HomeMy WebLinkAboutPD 2023-0012; VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION; GEOTECHNICAL REPORT FOR VALLEY MIDDLE SCHOOL MODERNIZATION; 2023-02-16
4373 Viewridge Avenue Suite B San Diego, California 92123 858.292.7575 944 Calle Amanecer Suite F San Clemente, CA 92673 949.388.7710 www.usa-nova.com
NOVA Project No. 2022253
February 16, 2023
Valley Middle School Modernization
1645 Magnolia Avenue, Carlsbad, CA 92008
Submitted to:
Carlsbad Unified School District
6225 El Camino Real
Carlsbad, CA 92009
UPDATE GEOTECHNICAL REPORT
-~ CARLSBAD ~~-Unified School District
Jl \ , ••
NOVA
Services
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION DVBE SBE SDVOSB SLBE
4373 Viewridge Avenue, Suite B
San Diego, CA 92123
P: 858.292.7575
www.usa-nova.com 944 Calle Amanecer, Suite F
San Clemente, CA 92673
P: 949.388.7710
Chad Conrad, Bond Program Manager February 16, 2023
Carlsbad Unified School District NOVA Project No. 2022253
6225 El Camino Real
Carlsbad, California 92009
Subject: Update Geotechnical Report
Valley Middle School Modernization
1645 Magnolia Avenue, Carlsbad, California 92008
Dear Mr. Conrad:
NOVA Services, Inc. (NOVA) is pleased to present our update geotechnical report for the Valley Middle
School Modernization project. NOVA’s services were conducted in accordance with our proposal dated
November 11, 2022 and our change order request dated January 27, 2023. Our work was completed
in accordance with Chapter 18A of Title 24, Part 2 of the 2022 California Building Code (CBC) and
California Geological Survey (CGS) Note 48, which includes requirements for geotechnical evaluation
of public-school sites.
This site is considered geotechnically suitable for the proposed improvements provided the
recommendations within this report are followed.
NOVA appreciates the opportunity to be of continued service to Carlsbad Unified School District. If you
have any questions regarding this report, please do not hesitate to call us at 858.292.7575 x 413.
Sincerely,
NOVA Services, Inc.
___________________________ _________________________
Melissa Stayner, CEG 2707 Tom Canady, PE 50057
Senior Engineering Geologist Principal Engineer
________________________
John F. O’Brien, GE 651
Principal Geotechnical Engineer
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
i
UPDATE GEOTECHNICAL REPORT
Valley Middle School Modernization
1645 Magnolia Avenue, Carlsbad, CA 92008
TABLE OF CONTENTS
1. INTRODUCTION ...................................................................................................... 1
2. SCOPE OF WORK .................................................................................................. 3
2.1. Subsurface Exploration .............................................................................................. 3
2.2. Laboratory Testing ..................................................................................................... 4
2.3. Borehole Percolation Testing ..................................................................................... 4
2.4. Analysis and Report Preparation ................................................................................ 4
3. SITE AND PROJECT DESCRIPTION ..................................................................... 5
3.1. Site Description .......................................................................................................... 5
3.2. Proposed Construction ............................................................................................... 5
4. GEOLOGY AND SUBSURFACE CONDITIONS ..................................................... 6
4.1. Regional Geology ....................................................................................................... 6
4.2. Site-Specific Geology ................................................................................................. 7
4.3. Groundwater .............................................................................................................. 7
4.3.1 Water Table Aquifer ...................................................................................... 8
4.3.2 Perched Water .............................................................................................. 8
5. GEOLOGIC HAZARDS ........................................................................................... 9
5.1. Faulting and Surface Rupture ..................................................................................... 9
5.2. Historical Seismicity ................................................................................................... 9
5.3. Site Class ................................................................................................................. 10
5.4. Seismic Design Parameters ..................................................................................... 10
5.4.1 ASCE 7-16 .................................................................................................. 10
5.5. Landslides and Slope Stability .................................................................................. 11
5.6. Liquefaction and Seismic Compression .................................................................... 11
5.7. Flooding, Tsunamis, and Seiches ............................................................................. 11
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
ii
5.8. Subsidence .............................................................................................................. 11
5.9. Hydro-Consolidation ................................................................................................. 11
6. CONCLUSIONS ..................................................................................................... 12
7. RECOMMENDATIONS .......................................................................................... 13
7.1. Earthwork ................................................................................................................. 13
7.1.1 Site Preparation .......................................................................................... 13
7.1.2 Remedial Grading – Building 900 ................................................................ 13
7.1.3 Remedial Grading – Pedestrian Hardscape ................................................ 13
7.1.4 Remedial Grading – Site Walls and Retaining Walls ................................... 14
7.1.5 Expansive Soil............................................................................................. 14
7.1.6 Compacted Fill ............................................................................................ 14
7.1.7 Subgrade Stabilization ................................................................................ 14
7.1.8 Imported Soil ............................................................................................... 14
7.1.9 Excavation Characteristics .......................................................................... 14
7.1.10 Oversized Material ...................................................................................... 15
7.1.11 Temporary Excavations ............................................................................... 15
7.1.12 Temporary Shoring ..................................................................................... 15
7.1.13 Surface Drainage ........................................................................................ 15
7.1.14 Grading Plan Review................................................................................... 16
7.2. Foundations ............................................................................................................. 16
7.2.1 General ....................................................................................................... 16
7.2.2 Spread Footings .......................................................................................... 16
7.2.3 CIDH Piles .................................................................................................. 17
7.2.4 Settlement Characteristics .......................................................................... 18
7.2.5 Foundation Plan Review ............................................................................. 18
7.2.6 Foundation Excavation Observations .......................................................... 18
7.3. Interior Slabs-On-Grade ........................................................................................... 18
7.4. Hardscape ................................................................................................................ 18
7.5. Conventional Retaining Walls ................................................................................... 19
7.5.1 Foundations ................................................................................................ 19
7.5.2 Earth Pressures .......................................................................................... 19
7.5.3 Seismic Increment ....................................................................................... 19
7.5.4 Drainage ..................................................................................................... 19
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
iii
7.5.5 Backfill ........................................................................................................ 20
7.6. Pavements ............................................................................................................... 21
7.7. Pipelines .................................................................................................................. 21
7.8. Corrosivity ................................................................................................................ 22
8. INFILTRATION FEASIBILITY................................................................................ 23
8.1. Public Health and Safety Considerations .................................................................. 24
8.2. Conclusions.............................................................................................................. 25
9. CLOSURE .............................................................................................................. 26
10. REFERENCES ..................................................................................................... 27
List of Figures
Figure 1-1. USGS Quadrangle Map
Figure 1-2. Site Location Map Presenting Areas of Campus Improvements
Figure 2-1. Subsurface Investigation Map
Figure 4-1. Regional Geology Map
Figure 4-2. Old Paralic Deposits in Boring B-2
Figure 5-1. Faulting in the Site Vicinity
Figure 7-1. Typical Conventional Retaining Wall Backdrain Details
Figure 8-1. Infiltration Restriction Considerations
List of Tables
Table 5-1. 2022 CBC and ASCE 7-16 Seismic Design Parameters
Table 7-1. AC and PCC Pavement Sections
Table 8-1. Infiltration Rates Determined by Percolation Testing
List of Plates
Plate 1 Geotechnical Map
Plate 2 Cross-Section A-A’ and B-B’
List of Appendices
Appendix A Use of the Geotechnical Report
Appendix B Boring Logs
Appendix C Geotechnical Laboratory Testing
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
1
1. INTRODUCTION
This report presents NOVA’s geotechnical update for the proposed Valley Middle School
Modernization project, located at 1645 Magnolia Avenue in the City of Carlsbad, San Diego County,
California. NOVA previously performed a geotechnical investigation at the site for remodeling the
interior of Building 900 and constructing a new canopy at the front entrance (NOVA, 2023). Other
currently proposed improvements include three areas of new flatwork, two new ADA ramps, two new
shade structures, new stormwater Best Management Practices (BMPs) facilities constructed as tree
wells in front of Building 900, and a stormwater capture and infiltration vault east of Building 500.
The purpose of NOVA’s work is to provide recommendations regarding the geotechnical aspects of
the project.
Figure 1-1 presents the site location on a United States Geologic Survey (USGS) 7.5 Minute
Quadrangle Map. Figure 1-2 presents a site location map.
Figure 1-1. USGS Quadrangle Map (Source: San Luis Rey 7.5 Minute Quadrangle, 1997)
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
2
Figure 1-2. Site Location Map Presenting Areas of Campus Improvements
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
3
2. SCOPE OF WORK
2.1. Subsurface Exploration
NOVA explored the subsurface conditions by drilling two geotechnical borings (B-1 through B-2), five
hand auger boring (HA-1 through HA-5) and four percolation test borings (P-1 through P-4) to depths
up to about 20½ feet below the ground surface (bgs). Boring B-1 was drilled using a truck-mounted,
hollow-stem auger drill rig. Boring B-2 and the percolation borings were drilled using a track-mounted,
limited access, hollow-stem auger drill rig. Borings HA-1 through HA-5 were drilled using a hand auger.
The boring locations were coordinated with the architect, civil engineer, and landscape architect. We
also utilized the results of our previous shear wave velocity survey (NOVA, 2020) and two previous
borings by SCST (2014). Figure 2-1 presents the approximate locations of the borings. Plate 1 presents
the exploration locations on a larger scale.
Figure 2-1. Subsurface Investigation Map
-
:. ~
~ ~ ~
7
®
I_ j, ., ,'
HA-5
@
P-4
HANO AUGER BORING
(NOVA, 2023)
BOREHOLE
PERCOLATION TEST
B-2
8
S-1
1----1
CJ
GEOTECHNICAL BORING
(SCST, 2014)
SEISMIC SHEAR WAVE
SURVEY, (NOVA, 2020)
PROPOSED FLATWORK
IMPROVEMENT AREAS
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
4
A NOVA geologist logged the borings and collected samples of the materials encountered for
laboratory testing. Relatively undisturbed samples were obtained using a modified California (CAL)
sampler, a ring-lined split tube sampler with a 3-inch outer diameter and 2½-inch inner diameter.
Standard Penetration Testing (SPT) was performed in the borings using a 2-inch outer diameter and
1⅜-inch inner diameter split tube sampler. The CAL and SPT samplers were driven using an automatic
hammer with a calibrated Energy Transfer Ratios (ETR) of 70.6% (CME 95) or 80.8% (CME 75 LAR).
The number of blows needed to drive the sampler 18 inches is noted in three, 6-inch intervals on the
logs. Sampler refusal was encountered when 50 blows were applied during any one of the three 6-
inch intervals, a total of 100 blows was applied, or there was no discernible sampler advancement
during the application of 10 successive blows. The field blow counts, N, were corrected to a standard
hammer (cathead and rope) with a 60% ETR. The corrected blow counts are noted on the boring logs
as N60. Disturbed bulk samples were obtained from the SPT sampler and the drill cuttings.
Logs of the borings are presented in Appendix B. Soils are classified according to the Unified Soil
Classification System
2.2. Laboratory Testing
NOVA tested selected samples from the borings to evaluate soil classification and engineering
properties and develop geotechnical conclusions and recommendations. The laboratory tests
consisted of particle-size distribution, Atterberg limits, expansion index, R-value, corrosivity, and direct
shear.
The results of the laboratory tests and brief explanations of the test procedures are presented in
Appendix C.
2.3. Borehole Percolation Testing
Borehole percolation testing was performed in P-1 through P-4 to evaluate feasibility of stormwater
infiltration. Borehole percolation testing was performed in accordance with the test method described
in the City of Carlsbad BMP Design Manual, January 2023 Edition (hereinafter `BMP Manual'). The
procedure and results are discussed in Section 8 of this report.
2.4. Analysis and Report Preparation
The results of the field investigation and laboratory testing were evaluated to develop conclusions and
recommendations regarding the geotechnical aspects of the proposed construction and site
improvements.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
5
3. SITE AND PROJECT DESCRIPTION
3.1. Site Description
The site is bounded on the northwest by Magnolia Avenue, on the northeast by Valley Street, on the
southwest by residential development, and on the southeast by Valley Middle School sports fields and
tennis courts.
The campus slopes to the west, with ground surface elevations ranging from about El +180 feet mean
sea level (msl) along the eastern boundary to +150 feet along the western boundary. However, as
seen in Figure 2-1, the areas of the proposed improvements are generally localized to areas in the
center of the campus where elevations are generally around +163 feet msl.
A review of historic aerial photos shows that the site was used for agricultural purposes until about
1966, when the existing school was constructed.
3.2. Proposed Construction
The project will consist of remodeling the interior of Building 900 and constructing a new canopy at the
front entrance. Along the center of the campus there are three areas of new flatwork proposed: in front
of Building 900, behind Building 900, and behind the Multi-Purpose Room (MPR). Two new shade
structures are proposed in the open area behind Building 900 and behind the MPR. Two new ADA
ramps are proposed along the north eastern portion of the campus near the parking lots. These ramps
will be constructed using small retaining walls. New stormwater BMPs will be constructed as tree wells
in front of Building 900, and a stormwater capture and infiltration vault between Building 500 and the
library. These areas of proposed improvements are called out on Plate 1.
NOVA’s understanding of planning for the Valley Middle School campus modernization is based in
part upon review of the current precise grading plan (PLSA, 2022), architectural drawings (ASDG
2022), and landscape design drawings (ASDG 2023). In addition, NOVA discussed planning for
Building 900 foundations with the structural engineer.
Building 900 is a single-story structure. Proposed construction includes remodeling the inside of
Building 900 and construction of a new canopy at the front entrance. Remodeling may drive a
requirement for construction of new interior footings. NOVA is advised that loads to footings will be
consistent with those used for the original design. Changes to existing wall loads will likely be
negligible. Loads from the canopy to foundations will be light. Uplift related to wind loads may be a
primary consideration in foundation design for the canopy in front of Building 900 and the two proposed
shade structures located south of Building 900 and the multi-purpose building, respectively.
It is expected that earthwork will be minimal, primarily consisting of remedial grading for the new
flatwork. The civil engineer estimates earthwork will be associated with about 500 cubic yards (cy) of
cut and 200 cy of fill, exporting a net 300 cy of soil.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
6
4. GEOLOGY AND SUBSURFACE CONDITIONS
4.1. Regional Geology
The site is located within the Peninsular Ranges Geomorphic Province of California, which stretches
from the Los Angeles basin to the tip of Baja California in Mexico. This province is characterized as a
series of northwest-trending mountain ranges separated by subparallel fault zones and a coastal plain
of subdued landforms. The mountain ranges are underlain primarily by Mesozoic metamorphic rocks
that were intruded by plutonic rocks of the Peninsular Ranges Batholith, while the coastal plain is
underlain by subsequently deposited marine and nonmarine sedimentary formations. The site is
located within the coastal plain portion of the province and is underlain Quaternary old paralic deposits,
Unit 2-4.
Figure 4-1 presents the regional geology in the vicinity of the site. Plate 2 following the text of this
report presents the geologic cross-sections across the areas of proposed construction and
improvements.
Figure 4-1. Regional Geology Map
KEY TO SYMBOLS
I Qop2_4 I oLDPARAucDEPos1Ts, I Qvop12 I UNIT 2-4, UNDIVIDED
I Qop6_7 I oLDPARAucDEPos1Ts, I Qvop13 I UNIT 6-7, UNDIVIDED
VERY OLD PARALIC
DEPOSITS, UNIT 12
VERY OLD PARALIC
DEPOSITS, UNIT 13
SANTIAGO FORMATION
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
7
4.2. Site-Specific Geology
Subsurface investigations by NOVA and SCST indicate that the site is underlain by Quaternary-aged
old paralic deposits (SCST 2014), with localized areas with thin layers of fill, less than 4 feet in
thickness. It appears the portion of the campus where Building 900 is located is cut into the old paralic
deposits. Based on the geotechnical borings performed by NOVA and SCST, the elevation of the old
paralic deposits is generally consistent along the center of the campus where the proposed
improvements are located. The description of the material encountered in the borings is presented
below. Plate 1 (provided following the text of the report) presents the site-specific geology. Plate 2
presents geologic cross-sections.
Fill (af): Fill was encountered in borings B-2, HA-1 through HA-5, and P-1 through P-4 to depths
between about ½ to 3½ feet bgs. As encountered in the borings, the fill generally consisted of loose
clayey sand, silty sand, and poorly graded sand. NOVA has no records regarding the placement and
compaction of the fill; therefore, it is considered undocumented and at risk for variations in quality.
Quaternary Old Paralic Deposits (Qop2-4): Old paralic deposits were encountered in each of
the borings. As encountered in the borings, these deposits consisted of medium dense to very
dense, weakly cemented silty to clayey sandstone and poorly graded sandstone. Testing of the
near-surface materials indicated a very low expansion potential. These deposits are considered
suitable for support of the proposed campus structures and improvements. Figure 4-2 presents
a photograph of the old paralic deposits encountered in B-2.
Figure 4-2. Old Paralic Deposits in Boring B-2
4.3. Groundwater
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
8
4.3.1 Water Table Aquifer
Groundwater was not encountered in the borings to the maximum-explored depth of 20½ feet bgs.
The groundwater table is expected to be below a depth that could affect the planned construction.
4.3.2 Perched Water
Perched groundwater conditions may occur in the future due to changes in land use and/or following
periods of heavy rain. Seasonal fluctuations of groundwater elevations should be expected over time.
In general, local zones of perched groundwater may be develop within the near-surface deposits due
to local landscape irrigation or precipitation, especially during rainy seasons. Because such
groundwater rise or seepage is difficult to predict, such conditions are typically mitigated if and when
they occur.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
9
5. GEOLOGIC HAZARDS
5.1. Faulting and Surface Rupture
There are no known active faults underlying the site. The nearest mapped active faults are offshore
approximately 8.6 kilometers to the southwest, within the oceanside section of the Newport-Inglewood-
Rose Canyon Fault Zone. Due to the lack of active faulting, the probability of fault rupture at this site
is considered low. Figure 5-1 reproduces mapping of faulting in the site vicinity.
Figure 5-1. Faulting in the Site Vicinity
5.2. Historical Seismicity
Most of the large historical earthquakes that have been documented in this area of San Diego County
have occurred east of the site, 60 or more miles away. Most of these appear to be on splays of the
San Jacinto Fault Zone. In 1954 the San Jacinto Fault Earthquake (Mw 6.4) cracked plaster walls in
\
\
\
\
\
\
\
Fa ult a Ion g l'lhich historic (last 200
years) displacement has occurred
-------~
Holocene fault displacement (during past
11,700 ,ears) l'\ilhout histonc record.
-~ncin it
. \
1\l.
KEY TO SYMBOLS
-------4
Lale Quaternary fault displacement
(during past 700,000 ,ears).
----- ---*
Quaternary fault (age undifferentiated).
-------4
Pre-Quaternary fault (older than 1.6 million years) or
fault wthout recognized Quaternary displacement.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
10
San Diego. In 1968 the Borrego Mountain Earthquake (Mw 6.5) reportedly severed powerlines in San
Diego County. Two additional large quakes without local damage reports have been noted from the
SCEC website: The Imperial Valley Earthquake (Mw 6.4) on October 15, 1979, and the Superstition
Hills Earthquake (Mw 6.6) In 1987. In summary, in the event of a large earthquake on one of the larger
southern California fault zones, ground motion acceleration may be noted at the site, but it appears
doubtful based on historical seismicity that the proposed structure will experience anything more than
minor cosmetic damage.
5.3. Site Class
Site Class is determined by the weighted average of shear-wave velocity or standard penetration
resistance (N-value) within the upper 100 feet of the soil and rock beneath a site. Sites underlain by
soil and rock with a weighted average standard penetration resistance greater than 50 blows per foot
within the upper 100 feet are classified as Site Class C. Based on the penetration resistances
encountered in our borings, the site is classified as Site Class C in accordance with Table 20.3-1 and
the formulas in Section 20.4 of ASCE 7-16. Additionally, in 2020 NOVA performed shear wave testing
within the eastern parking lot at Valley Middle School during design of a new solar structure. The Vs100
was found to be 1,284 feet/second, which is a Site Class C in accordance with ASCE 7-16.
5.4. Seismic Design Parameters
5.4.1 ASCE 7-16
The site coefficients and maximum considered earthquake (MCER) spectral response acceleration
parameters per the 2022 CBC and ASCE 7-16 for Site Class C are presented in Table 5-1.
Table 5-1. 2022 CBC and ASCE 7-16 Seismic Design Parameters
Site Coordinates
Latitude: 33.158636° Longitude: -117.3296°
Site Coefficients and Spectral Response Acceleration Parameters Value
Site Class C
Site Coefficients, Fa 1.2
Site Coefficients, Fv 1.5
Mapped Spectral Response Acceleration at Short Period, Ss 1.037g
Mapped Spectral Response Acceleration at 1-Second Period, S1 0.377g
Mapped Design Spectral Acceleration at Short Period, SDS 0.829g
Design Spectral Acceleration at 1-Second Period, SD1 0.377g
Site Peak Ground Acceleration, PGAM 0.55g
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
11
5.5. Landslides and Slope Stability
Evidence of landslides, deep-seated landslides, or slope instabilities were not observed at the time of
the field investigation. Additionally, there are no mapped landslides in the vicinity of the project site.
Due to the flat-lying geologic structure underlying the site, the potential for landslides or slope
instabilities to occur at the site is considered very low.
5.6. Liquefaction and Seismic Compression
Liquefaction occurs when loose, saturated, generally fine sands and silts are subjected to strong
ground shaking. The soils lose shear strength and become liquid, resulting in large total and differential
ground surface settlements, as well as possible lateral spreading during an earthquake. Due to the
lack of shallow groundwater and given the very dense, cemented nature of the sandstones beneath
the site, there is no potential for liquefaction.
As used herein, seismic compression is intended to describe the accrual of contractive volumetric
strains in unsaturated sands and silts because of a seismic event. Variously also referenced as
‘dynamic settlement’ and ‘dry sand settlement’, the phenomenon is well recognized as a cause of
seismically induced damage to structures and infrastructure. The dense, cemented sandstones
beneath this site are not at risk for seismic compression.
5.7. Flooding, Tsunamis, and Seiches
The site is mapped within an area of minimal flood hazard (FEMA, 2012). The site is not located within
a mapped area on the Tsunami Hazard Area Map for San Diego County (CGS, 2022a); therefore,
damage due to tsunamis is considered negligible. Seiches are periodic oscillations in large bodies of
water such as lakes, harbors, bays, or reservoirs. The site is not located adjacent to any lakes or
confined bodies of water; therefore, the potential for a seiche to affect the site is considered negligible.
5.8. Subsidence
The site is not located in an area of known subsidence associated with fluid withdrawal (groundwater
or petroleum); therefore, the potential for subsidence due to the extraction of fluids is considered
negligible.
5.9. Hydro-Consolidation
Hydro-consolidation can occur in recently deposited sediments (less than 10,000 years old) that were
deposited in a semi-arid environment. Examples of such sediments are eolian sands, alluvial fan
deposits, and mudflow sediments deposited during flash floods. The pore spaces between the particle
grains can readjust when inundated by groundwater, causing the material to consolidate. The potential
for hydro-consolidation can be reduced by over excavation and recompaction of the materials
susceptible to hydro-consolidation. The formational sandstone deposits underlying the site are not
susceptible to hydro-consolidation.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
12
6. CONCLUSIONS
Based on the findings of this investigation, NOVA considers the proposed construction feasible from a
geotechnical standpoint provided the recommendations contained in this report are followed.
Geotechnical conditions exist that should be addressed prior to construction.
Geotechnical design and construction considerations include the following.
• There are no known active faults underlying the site. The primary seismic hazard at the site is
the potential for moderate to severe ground shaking in response to large-magnitude
earthquakes generated during the lifetime of the proposed construction. The risk of strong
ground motion is common to all development in this area of California and is typically mitigated
through building design in accordance with the CBC. While strong ground motion could affect
the site, the risk of liquefaction or related seismic phenomena is considered negligible.
• The site is underlain by Quaternary-aged old paralic deposits (Qop) to the maximum-explored
depths. The old paralic deposits are considered suitable for support of fill or structural loads.
The upper 2 feet of the old paralic deposits are considered potentially compressible and
unsuitable for support of structural or fill loads. Recommendations for remedial grading are
provided in this report.
• The on-site soils have a very low expansion potential. These soils are suitable for reuse as
compacted fill. Expansive clays, if encountered, are not considered suitable for direct support of
buildings or heave-sensitive improvements.
• In general, the old paralic deposits are anticipated to be readily excavatable using standard
heavy earthmoving equipment in good-working order with experienced operators. Localized
cemented formational materials may require extra excavation effort.
• The proposed canopy structure at the entrance of Building 900, the two shade structures, and
the two ADA ramp retaining walls can be supported on shallow spread footings bearing either
entirely on formational materials or entirely on compacted fill. Recommendations for foundations
are provided in this report. Loads from the canopy to foundations will be light, such that transitory
uplift loads related to wind may control foundation selection.
• Groundwater was not encountered in either the NOVA borings or the 2014 borings by SCST.
The permanent groundwater table is anticipated to be below a depth that will affect the proposed
development. See page related to perched water could develop in the future. Because seepage
is difficult to predict, such conditions are typically mitigated if and when they occur.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
13
7. RECOMMENDATIONS
The remainder of this report presents recommendations regarding earthwork construction as well as
preliminary geotechnical recommendations for the design of the proposed improvements. These
recommendations are based on empirical and analytical methods typical of the standard-of-practice in
southern California. If these recommendations appear not to address a specific feature of the project,
please contact our office for additions or revisions to the recommendations.
7.1. Earthwork
Grading and earthwork should be conducted in accordance with the CBC and the recommendations
of this report. The following recommendations are provided regarding specific aspects of the proposed
earthwork construction. These recommendations should be considered subject to revision based on
field conditions observed by NOVA staff during grading.
7.1.1 Site Preparation
Site preparation should begin with the removal of existing improvements, vegetation, and debris.
Subsurface improvements that are to be abandoned should be removed, and the resulting excavations
should be backfilled and compacted in accordance with the recommendations of this report. Pipeline
abandonment can consist of capping or rerouting at the project perimeter and removal within the
project perimeter. If appropriate, abandoned pipelines can be filled with grout or slurry as
recommended by and observed by the geotechnical consultant.
7.1.2 Remedial Grading – Building 900
Formational sandstones were encountered within a foot of the ground surface at existing Building 900.
Any fill encountered at the location of new foundations should be removed to contact with the level of
the formational sandstones. Horizontally, this removal should extend the limits of the new foundation.
Thereafter, new foundations should be embedded a minimum of 6 inches into competent formational
sandstone. To accommodate bearing on formational sandstone, 2-sack sand/cement slurry can be
placed between the bottom of footing and the underlying formation.
7.1.3 Remedial Grading – Pedestrian Hardscape
Beneath proposed hardscape, the on-site soils should be excavated to a depth of at least 2 feet below
planned subgrade elevation. Horizontally, the excavations should extend at least 2 feet outside the
planned hardscape or up to existing improvements, whichever is less. If competent formational
materials are exposed, excavation need not be performed. NOVA should observe the conditions
exposed in the bottom of excavations to evaluate whether additional excavation is recommended. The
resulting surface should then be scarified to a depth of 6 to 8 inches, moisture conditioned to near
optimum moisture content, and compacted to at least 90% relative compaction. If competent
formational materials are exposed, scarification and recompaction need not be performed. The
excavation should be filled with compacted fill having an expansion index (EI, after ASTM D4829) of
EI ≤ 20.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
14
7.1.4 Remedial Grading – Site Walls and Retaining Walls
Beneath proposed site walls and retaining walls not connected to buildings, the existing surface soils
should be excavated to a depth of at least 2 feet below bottom of footing. Horizontally, the excavations
should extend at least 2 feet outside the planned hardscape, wall footing, or up to existing
improvements, whichever is less. If competent formational materials are exposed below the entire wall,
over-excavation need not be performed. NOVA should observe the conditions exposed in the bottom
of excavations to evaluate whether additional excavation is recommended. Any required fill should
have an EI ≤ 20.
7.1.5 Expansive Soil
The on-site soils tested have EI = 0, classified as very low expansion potential. To reduce the potential
for expansive heave, the top 2 feet of material beneath building footings, concrete slabs-on-grade,
hardscape, and site and retaining wall footings should have EI ≤ 20. Horizontally, the soils having EI ≤
20 should extend at least 5 feet outside the planned perimeter building foundations, at least 2 feet
outside site/retaining wall footings and hardscape, or up to existing improvements, whichever is less.
NOVA expects that the on-site sands will meet the EI criterion.
7.1.6 Compacted Fill
Fill and backfill should be placed in 6- to 8-inch-thick loose lifts, moisture conditioned 2% over optimum
moisture content and compacted to at least 90% relative compaction. The maximum density and
optimum moisture content for the evaluation of relative compaction should be determined in
accordance with ASTM D1557.
7.1.7 Subgrade Stabilization
Excavation bottoms should be firm and unyielding prior to placing fill. In areas of saturated or yielding
subgrade, a reinforcing geogrid such as Tensar® Triax® TX-5 or equivalent can be placed on the
excavation bottom, and then at least 12 inches of aggregate base placed and compacted. Once the
surface of the aggregate base is firm enough to achieve compaction, then the remaining excavation
should be filled to finished grade with suitable material.
7.1.8 Imported Soil
Imported soil should consist of predominately granular soil, free of organic matter, and rocks greater
than 6 inches with an expansion index (EI) of EI <20 after ASTM D4829. Imported soil should be
observed and, if appropriate, tested by NOVA prior to transport to the site to evaluate suitability for the
intended use.
7.1.9 Excavation Characteristics
Given the shallow earthwork anticipated to complete the improvements, difficult excavation is not
anticipated. Material encountered during the earthwork is expected to be readily excavated with typical
construction equipment for a project of this scope.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
15
7.1.10 Oversized Material
Excavations may generate oversized material. Oversized material is defined as rocks or cemented
clasts greater than 6 inches in largest dimension. Oversized material should be broken down to no
greater than 6 inches in largest dimension to be used in fill. Oversized material greater than 6 inches
may be used as landscape material or disposed of off-site.
7.1.11 Temporary Excavations
Temporary excavations 3 feet deep or less can be made vertically. Deeper temporary excavations in
fill should be laid back no steeper than 1:1 (horizontal:vertical). Deeper temporary excavations in old
paralic deposits should be laid back no steeper than ¾:1 (h:v). The faces of temporary slopes should
be inspected daily by the contractor’s Competent Person before personnel are allowed to enter the
excavation. Any zones of potential instability, sloughing, or raveling should be brought to the attention
of the engineer and corrective action implemented before personnel begin working in the excavation.
Excavated soils should not be stockpiled behind temporary excavations within a distance equal to the
depth of the excavation. NOVA should be notified if other surcharge loads are anticipated so that lateral
load criteria can be developed for the specific situation. If temporary slopes are to be maintained during
the rainy season, berms are recommended along the tops of slopes to prevent runoff water from
entering the excavation and eroding the slope faces.
Slopes steeper than those described above will require shoring. Additionally, temporary excavations
that extend below a plane inclined at 1½:1 (h:v) downward from the outside bottom edge of existing
structures or improvements will require shoring. Soldier piles and lagging, internally braced shoring, or
trench boxes could be used. If trench boxes are used, the soil immediately adjacent to the trench box
is not directly supported. Ground surface deformations immediately adjacent to the pit or trench could
be greater where trench boxes are used compared to other methods of shoring.
7.1.12 Temporary Shoring
For design of cantilevered shoring with level backfill, an active earth pressure equal to a fluid weighing
35 pounds per cubic foot (pcf) can be used. An additional 20 pcf should be added for 2:1 (h:v) sloping
ground. The surcharge loads on shoring from traffic and construction equipment working adjacent to
the excavation can be modeled by assuming an additional 2 feet of soil behind the shoring. For design
of soldier piles, an allowable passive pressure of 350 pounds per square foot (psf) of embedment can
be used, over two times the pile diameter up to a maximum of 5,000 psf. Soldier piles should be spaced
at least three pile diameters apart, center on center.
7.1.13 Surface Drainage
Final surface grades around structures should be designed to collect and direct surface water away
from structures, including retaining walls, and toward appropriate drainage facilities. The ground
around the structure should be graded so that surface water flows rapidly away from the structure
without ponding. In general, NOVA recommends that the ground adjacent to the structure slope away
at a gradient of at least 2%. Densely vegetated areas where runoff can be impaired should have a
minimum gradient of at least 5% within the first 5 feet from the structure.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
16
Roof gutters with downspouts that discharge directly into a closed drainage system are recommended
on structures. Drainage patterns established at the time of fine grading should be maintained
throughout the life of the proposed structures. Site irrigation should be limited to the minimum
necessary to sustain landscape growth. Should excessive irrigation, impaired drainage, or unusually
high rainfall occur, saturated zones of perched groundwater can develop.
7.1.14 Grading Plan Review
NOVA should review the grading plans and earthwork specifications to ascertain whether the intent of
the recommendations contained in this report have been implemented, and that no revised
recommendations are needed due to changes in the development scheme.
7.2. Foundations
7.2.1 General
The foundation recommendations provided herein are considered generally consistent with methods
typically used in southern California. Other alternatives may be available. These recommendations are
only minimum criteria based on geotechnical factors and should not be considered a structural design
or preclude more restrictive criteria of governing agencies or the structural engineer. The design of the
foundation system should be performed by the structural engineer, incorporating the geotechnical
parameters described herein and the requirements of applicable building codes.
New footings for Building 900, the proposed canopy at the entrance of the building, ADA ramp retaining
walls, and the two proposed shade structures may be shallow spread footings with bottom levels
bearing on the formational sandstones.
Site walls and retaining walls not connected to buildings can be supported on shallow spread footings
with bottom levels bearing on formational materials or compacted fill
7.2.2 Spread Footings
Bearing
Footings should extend at least 24 inches below lowest adjacent finished grade and embed a minimum
6 inches into sound formational sandstone. A minimum width of 12 inches is recommended for
continuous footings and 24 inches for isolated or wall footings. An allowable bearing capacity of 4,500
psf can be used for footings supported on the formational sandstones. The allowable bearing capacity
can be increased by 500 psf for each foot of depth below the minimum and 250 psf for each foot of
width beyond the minimum up to a maximum of 6,000 psf. The bearing value can be increased by ⅓
when considering the total of all loads, including wind or seismic forces. Footings located adjacent to
or within slopes should be extended to a depth such that a minimum horizontal distance of 10 feet
exists between the lower outside footing edge and the face of the slope.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
17
Lateral Resistance
Lateral loads will be resisted by friction between the bottoms of footings and passive pressure on the
faces of footings and other structural elements below grade. An allowable coefficient of friction of 0.35
can be used. An allowable passive pressure of 350 psf per foot of depth below the ground surface can
be used for level ground conditions.
The allowable passive pressure should be reduced for sloping ground conditions. The passive
pressure can be increased by ⅓ when considering the total of all loads, including wind or seismic
forces. The upper 1 foot of soil should not be relied on for passive support unless the ground is covered
with pavements or slabs.
Uplift Resistance
Uplift resistance of footings can be developed from the weight of the footing and the overlying soils.
The weight of the soils will lie within a prism defined by diagonal planes extending up from the top of
the perimeter of the foundation to the ground surface at an angle of 20 degrees from the vertical.
The allowable uplift capacity should be taken as a sum of the effective weight of soil plus the dead
weight of the foundation, divided by an appropriate factor of safety. A soil unit weight of 115 pcf should
be used for the backfill above the footing.
7.2.3 CIDH Piles
Short cast-in-drilled hole (CIDH) piles can be used for uplift resistance. CIDH piles should be a
minimum of 10 inches diameter, spaced at least 3 diameters center on center, and be embedded at
least 4 pile diameters (3D) into formational sandstones.
The axial downward capacity of piles will be obtained from skin friction. The axial uplift resistance of
piles will be obtained by skin friction and the weight of the pile. An allowable downward skin friction of
400 psf and an allowable end bearing of 2,000 psf can be used. If end bearing is used, the bottom of
drilled holes should be cleaned of loose soil prior to placing concrete. The axial uplift capacity of piles
can be obtained from skin friction and the weight of the pile. An allowable uplift skin friction of 300 psf
can be used.
Lateral loads can be resisted by passive pressure on the piles. An allowable passive pressure of 350
psf per foot of embedment acting on twice the pile diameter up to a maximum of 5,000 psf can be
used, based on a lateral deflection up to ½ inch at the ground surface and level ground conditions.
The uplift and passive pressure values can be increased by ⅓ when considering the total of all loads,
including wind or seismic forces. The upper 1 foot of soil should not be relied on for passive support
unless the ground is covered with pavements or slabs.
Groundwater was not encountered in the borings. In the event seepage related to perched
groundwater occurs, installation will require procedures and equipment necessary to ensure a stable
hole free of loose soil. Hard drilling conditions could be encountered in cemented zones within the
formational sandstones. Piles should be filled with concrete immediately after drilling. The holes should
not be left open overnight.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
18
7.2.4 Settlement Characteristics
Total foundation settlements of either shallow foundations or piles are estimated to be less than 0.5
inch. Differential settlements between adjacent unevenly loaded columns and across continuous
footings are estimated to be less than ½ inch over a distance of 40 feet. Settlements will be elastic,
completing shortly after structural loads are applied.
7.2.5 Foundation Plan Review
NOVA should review the foundation plans to ascertain that the intent of the recommendations in this
report has been implemented and that revised recommendations are not necessary as a result of
changes after this report was completed.
7.2.6 Foundation Excavation Observations
A representative from NOVA should observe the foundation excavations prior to forming or placing
reinforcing steel.
7.3. Interior Slabs-On-Grade
Interior concrete slabs-on-grade should be underlain by at least 2 feet of material with an expansion
index of 20 or less. We recommend that conventional concrete slabs-on-grade floors may be designed
assuming a modulus of subgrade reaction (k) of k = 90 pounds per cubic inch (pci). It is recommended
that slabs be at least 5 inches thick and reinforced with at least No. 4 bars at 18 inches on center each
way. To reduce the potential for excessive cracking, concrete slabs-on-grade should be provided with
construction or ‘weakened plane’ joints at frequent intervals. The structural engineer should design on-
grade building slabs and joint spacing.
Moisture protection should be installed beneath slabs where moisture sensitive floor coverings will be
used. The architect should review the tolerable moisture transmission rate of the proposed floor
covering and specify an appropriate moisture protection system. Typically, a plastic vapor barrier is
used. Minimum 15-mil plastic is recommended. The plastic should comply with ASTM E1745. The
vapor barrier installation should comply with ASTM E1643. The slab can be placed directly on the
vapor barrier.
7.4. Hardscape
Hardscape should be underlain by at least 2 feet of material with EI ≤ 20. Exterior concrete slabs
should be at least 4 inches thick and reinforced with at least No. 3 bars at 18 inches on center each
way. Slabs should be provided with weakened plane joints. Joints should be placed in accordance with
the American Concrete Institute (ACI) guidelines. The architect should select the final joint patterns. A
1-inch maximum size aggregate mix is recommended for concrete for exterior slabs. The corrosion
potential of on-site soils with respect to reinforced concrete will need to be taken into account in
concrete mix design. Coarse and fine aggregate in concrete should conform to the “Greenbook”
Standard Specifications for Public Works Construction.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
19
7.5. Conventional Retaining Walls
7.5.1 Foundations
Conventional retaining walls can be supported on spread footings. The recommendations for spread
footings provided in the foundation section of this report are also applicable to conventional retaining
walls.
7.5.2 Earth Pressures
The active earth pressure for the design of unrestrained retaining walls with level backfill can be taken
as equivalent to the pressure of a fluid weighing 35 pcf. The at-rest earth pressure for the design of
restrained retaining wall with level backfill can be taken as equivalent to the pressure of a fluid weighing
55 pcf. These values assume a granular and drained backfill condition. Higher lateral earth pressures
would apply if walls retain clay soils. An additional 20 pcf should be added to these values for walls
with 2:1 (h:v) sloping backfill. An increase in earth pressure equivalent to an additional 2 feet of retained
soil can be used to account for surcharge loads from light traffic.
The above values do not include a factor of safety. Appropriate factors of safety should be incorporated
into the design. If any other surcharge loads are anticipated, NOVA should be contacted for the
necessary increase in soil pressure.
7.5.3 Seismic Increment
The seismic increment of lateral earth pressure for walls taller than 6 feet can be taken as equivalent
to the pressure of a fluid pressure weighing 20 pcf. This value is for level backfill and does not include
a factor of safety. Appropriate factors of safety should be incorporated into the design. This pressure
is in addition to the un-factored, active earth pressure. The total equivalent fluid pressure can be
modeled as a triangular pressure distribution with the resultant acting at a height of H/3 up from the
base of the wall, where H is the retained height of the wall. The passive resistance and bearing capacity
can be increased by ⅓ in determining the seismic stability of the wall.
7.5.4 Drainage
Retaining walls should be provided with a backdrain to reduce the accumulation of hydrostatic
pressures or be designed to resist hydrostatic pressures. Backdrains can consist of a 2-foot-wide zone
of ¾-inch crushed rock. The crushed rock should be separated from the adjacent soils using a non-
woven filter fabric, such as Mirafi 140N or equivalent. A perforated pipe should be installed at the base
of the backdrain and sloped to discharge to a suitable storm drain facility, or weep holes should be
provided.
As an alternative, a geocomposite drainage system such as Miradrain 6000 or equivalent placed
behind the wall and connected to a suitable storm drain facility can be used. The project architect
should provide dampproofing/waterproofing specifications and details. Figure 7-1 presents typical
conventional retaining wall backdrain details. Note that the guidance provided on Figure 7-1 is
conceptual. A variety of options are available to drain retaining walls.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
20
Figure 7-1. Typical Conventional Retaining Wall Backdrain Details
7.5.5 Backfill
Wall backfill should consist of granular, free-draining material having EI ≤ 20. The backfill zone is
defined by a 1:1 plane projected upward from the heel of the wall. Expansive or clayey soil should not
be used. Additionally, backfill within 3 feet from the back of the wall should not contain rocks greater
than 3 inches in dimension. Backfill should be compacted to at least 90% relative compaction.
Backfill should not be placed until walls have achieved adequate structural strength. Compaction of
wall backfill will be necessary to minimize settlement of the backfill and overlying settlement sensitive
improvements. However, some settlement should still be anticipated. Provisions should be made for
RETAINING
WALL
FIN ISHED
GRADE
CONCRETE
BROWDITCH
GROUND SURFACE
j __________ FILTER FABRIC ENVELOPE
(MIRAFI 140N OR APPROVED
EQUIVALENT)
12" 3/4" CRUSHED ROCK
(1 CU.FT./FT.)
FILTER FABRIC
ENVELOPE
MIRAFI 140N OR
EQUIVAL ENT
4" DIA. SCH EDULE 40
FOOTING PERFORATED PVC PIPE
OR TOTAL DRAIN
,'--..'-.:./j J\"'-,'--..'-.:./>-/~ EXTEND ED TO
APPROVED OUTLET
COM PETENT BE DROCK
OR MATERIAL AS
EVALUATED BY THE
GEOTECHNICAL
CONSULTANT
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
21
some settlement of concrete slabs and pavements supported on backfill. Additionally, any utilities
supported on backfill should be designed to tolerate differential settlement.
7.6. Pavements
The pavement support characteristics of the soils encountered during NOVA’s investigation are
considered low to medium. An R-value of 11 was assumed for design of preliminary pavement
sections. The actual R-value of the subgrade soils should be determined after grading, and the final
pavement sections should be provided. Based on an R-value of 11, preliminary pavement structural
sections are provided for the assumed traffic indexes on Table 7-1
Subgrade preparation should be performed immediately prior to placement of the pavement section.
The upper 12 inches of subgrade should be scarified, moisture conditioned to near optimum moisture
content, and compacted to at least 95% relative compaction. All soft or yielding areas should be
stabilized or removed and replaced with compacted fill or aggregate base.
Aggregate base and asphalt concrete should conform to the Caltrans Standard Specifications or the
“Greenbook” Standard Specifications for Public Works Construction and should be compacted to at
least 95% relative compaction. Aggregate base should have an R-value of not less than 78. All
materials and methods of construction should conform to good engineering practices and the minimum
local standards.
Table 7-1. AC and PCC Pavement Sections
Traffic Type Traffic Index Asphalt Concrete
(inches)
Portland Cement Concrete
(inches)
Parking Stalls 4.5 3 AC / 7 AB 7 PCC
Driveways 6.0 4 AC / 11 AB 7½ PCC
Fire Lanes 7.5 5 AC / 13 AB 8 PCC
AC: Asphalt Concrete
AB: Aggregate Base
PCC: Portland Cement Concrete
7.7. Pipelines
For level ground conditions, a passive earth pressure of 350 psf per foot of depth below the lowest
adjacent final grade can be used to compute allowable thrust block resistance. A value of 150 psf per
foot should be used below groundwater level, if encountered.
A modulus of soil reaction (E’) of 1,500 pounds per square inch (psi) can be used to evaluate the
deflection of buried flexible pipelines. This value assumes that granular bedding material is placed
adjacent to the pipe and is compacted to at least 90% relative compaction.
Pipe bedding as specified in the “Greenbook” Standard Specifications for Public Works Construction
can be used. Bedding material should consist of clean sand having a sand equivalent not less than 20
and should extend to at least 12 inches above the top of pipe. Alternative materials meeting the intent
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
22
of the bedding specifications are also acceptable. Samples of materials proposed for use as bedding
should be provided to the engineer for inspection and testing before the material is imported for use
on the project. The on-site materials are not expected to meet “Greenbook” bedding specifications.
The pipe bedding material should be placed over the full width of the trench. After placement of the
pipe, the bedding should be brought up uniformly on both sides of the pipe to reduce the potential for
unbalanced loads. No voids or uncompacted areas should be left beneath the pipe haunches. Ponding
or jetting the pipe bedding should not be allowed.
Where pipeline inclinations exceed 15%, cutoff walls are recommended in trench excavations.
Additionally, we do not recommend that open graded rock be used for pipe bedding or backfill because
of the potential for piping erosion. The recommended bedding is clean sand having a sand equivalent
not less than 20 or 2-sack sand/cement slurry. If sand/cement slurry is used for pipe bedding to at least
1 foot over the top of the pipe, cutoff walls are not considered necessary. The need for cutoff walls
should be further evaluated by the project civil engineer designing the pipeline.
7.8. Corrosivity
Representative samples of the on-site soils were tested to evaluate corrosion potential. The test results
are presented in Appendix B. The project design engineer can use the sulfate results in conjunction
with ACI 318 to specify the water/cement ratio, compressive strength, and cementitious material types
for concrete exposed to soil. A corrosion engineer should be contacted to provide specific corrosion
control recommendations.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
23
8. INFILTRATION FEASIBILITY
Final stormwater infiltration Best Management Practices (‘stormwater BMP’) locations were identified
by the civil engineer prior to the investigation. The stormwater BMP areas consist of three wells in front
of Building 900, and a stormwater capture and infiltration vault east of Building 500.
Four geotechnical borings (P-1 through P-4) were converted to borehole percolation tests following
the recommendations presented in the BMP Manual on January 28th, 2023. The borings were drilled
with a track-mounted drill rig to depths of about 5 feet bgs. Field measurements were taken to confirm
that the borings were drilled to approximately 8 inches in diameter. The borings were logged by a
NOVA geologist, who observed and recorded exposed soil cuttings and the boring conditions. Plate 1
depicts the locations of the percolation test wells and associated exploratory geotechnical borings.
This section provides the results of the testing performed on January 29th, 2023, and related
recommendations for management of stormwater in conformance with the BMP Manual.
Once the borings were drilled to the desired depth, approximately 2 inches of ¾-inch gravel was placed
on the bottom, then a 3-inch diameter Schedule 40 perforated PVC pipe was inserted into the borehole
that extended to the ground surface. The ¾-inch gravel was used to partially fill the annular space
around the perforated pipe below existing finish grade to minimize the potential of soil caving. The
borehole percolation tests were pre-soaked by filling the holes with water to the ground surface level
and testing commenced within a 26-hour window.
On the day of testing, two 25-minute trials were conducted in each well. The water did not percolate
over 6 inches within 25 minutes. Based on the results of the trials, water levels were recorded every
30 minutes for 6 hours. At the beginning of each test interval, the water level was raised to
approximately the same level as the previous tests, to maintain a near-constant head during the test
periods. It should be noted that the percolation rate of a soil profile is not the same as its infiltration
rate (‘I’). Therefore, the field percolation rates were converted to an estimated infiltration rate utilizing
the Porchet Method in accordance with guidance contained in the BMP Manual. Table 8-1 summarizes
the percolation test conditions and related infiltration rates.
Table 8-1. Infiltration Rates Determined by Percolation Testing
BMP
Location
Test
Wells
Depth
(feet)
Test Well
Ground
Surface
Elevations
(Feet, msl)
Materials at
Test Depth
Average
Infiltration
Rates
(in/hr,
FS=2)1
Infiltration
Condition
Northern
BMP
5 162 Old paralic deposits:
clayey sandstone
0.06 Partial
Infiltration
Southern
BMP
5 161 Old paralic deposits: silty
sandstone
0.18 Partial
Infiltration
Note 1: FS indicates ‘Factor of Safety’ as determined by Section D.2.3 ‘Safety Factors’
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
24
As shown in Table 8-1, a factor of safety (FS) is applied to the infiltration rate (I). Per the BMP Manual,
if the proposed BMP utilizes an underdrain, a default safety factor of 2 may be applied. This factor of
safety considers the nature and variability of subsurface materials, as well as the natural tendency of
infiltration structures to become less efficient with time.
8.1. Public Health and Safety Considerations
Appendix D.1 of the BMP Manual presents restriction elements that should be considered by the
project geotechnical professional while assessing the feasibility of infiltration related to geotechnical
conditions. These elements are listed in the Table D.1.1 (Figure 8-1). It is NOVA’s judgement that the
site is not restricted by elements that may pose a significant risk to human health and safety which
cannot be reasonably resolved through site design changes. As such, infiltration may be feasible;
however, when finalizing the BMP locations, the civil engineer should verify that BMPs are at least 10
feet from the nearest underground utility.
Figure 8-1. Infiltration Restriction Considerations
T able D.1-1: Considerations for Geotechnical Analysis of Infiltration Restrictions
Mandatory
Considerations
Optional
Considerations
Result
Restriction Element
BMP is within 100' of Con taminated Soils
Bt-.~ is within 100' of Industrial Activities Lacking Source Control
Bt-.~ is within 100' of Well/G roundwater Basin
Bt-.~ is within 50' of Septic Tanks/Leach Fields
BMP is within 10' of Structures/T anks/Walls
; .
; . .
; ..
Bt-.~ is within Highly Liquefiable Soils and has Connectivity to Structures
BMP is within 1.5 T imes the H eight of Adjacent Steep Slopes (2::25%)
County Staff has Assigned "Restricted" Infiltration Category
Bt-.~ is '.vithin Predominantly Type D Soil
Bt-.~ is '.vithin 1 0' of Property Line
Bt-.~ is '.vithin Fill Depths of 2::5' (Existing or Proposed)
Bt-.~ is within 1 0' of Underground tilities
Bt-.~ is within 250' of E phemeral Stream
Other (Provide detailed geotechnical support)
Based on e.,ramination of tl'le best available information,
Is Element
Applicable?
(Yes/No) -NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
!JI
I have not identified anv restrictions above. U nrestricted
Based on examination of tl'le best available information, D
I have identified one or more restrictions above. Restricted
Table D .1-1 1s divided into 1andatory Considerations and Optional Considerations. 1andatory
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
25
8.2. Conclusions
In consideration of the foregoing, it is NOVA’s judgment that the site is not restricted by elements that
may pose a significant risk to human health and safety which cannot be reasonably resolved through
site design changes. Design for the proposed BMPs may utilize an infiltration rate of 0.06 inches per
hour at the northern BMP (P-1 and P-2) and 0.18 inches per hour at the southern BMP (P-3 and P-4).
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
26
9. CLOSURE
NOVA should review project plans and specifications prior to bidding and construction to check that
the intent of the recommendations in this report has been incorporated. Observations and tests should
be performed during construction. If the conditions encountered during construction differ from those
anticipated based on the subsurface exploration program, the presence of personnel from NOVA
during construction will enable an evaluation of the exposed conditions and modifications of the
recommendations in this report or development of additional recommendations in a timely manner.
NOVA should be advised of changes in the project scope so that the recommendations contained in
this report can be evaluated with respect to the revised plans. Changes in recommendations will be
verified in writing. The findings in this report are valid as of the date of this report. Changes in the
condition of the site can, however, occur with the passage of time, whether they are due to natural
processes or work on this or adjacent areas. In addition, changes in the standards of practice and
government regulations can occur. Thus, the findings in this report may be invalidated wholly or in part
by changes beyond NOVA’s control. This report should not be relied upon after a period of two years
without a review by NOVA verifying the suitability of the conclusions and recommendations to site
conditions at that time.
In the performance of professional services, NOVA exercises the level of care and skill ordinarily
exercised by members of the geotechnical profession currently practicing under similar conditions and
in the same locality. The client recognizes that subsurface conditions may vary from those encountered
at the boring locations and that the data, interpretations, and recommendations reported herein are
based solely on the information obtained by NOVA. NOVA will be responsible for those data,
interpretations, and recommendations, but shall not be responsible for interpretations by others of the
information developed. Our services consist of professional consultation and observation only, and no
warranty whatsoever, express or implied, is made or intended in connection with the work performed
or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of
oral or written reports or findings.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
27
10. REFERENCES
AlphaStudio Design Group, 2022, Architectural Drawings, Carlsbad Unified School District, Valley
Middle School, 1645 Magnolia Ave., Carlsbad, California 92008, Campus Modernization, Sheets A-
101, A-215, A-216, A-807, Project 20-017, November 8, 2022.
______, 2023a, Landscape Drawings, Carlsbad Unified School District, Valley Middle School, 1645
Magnolia Ave., Carlsbad, CA 92008, Campus Modernization, 50% Construction Documents, Sheets
LT-100, LC-101, LC-102, Project 20-017, January 16, 2023.
______, 2023b, Autodesk, AutoCAD Drawings, Carlsbad Unified School District, Valley Middle School,
1645 Magnolia Ave., Carlsbad, CA 92008, Campus Modernization, 22118 Base.dwg, Project 20-017,
January 18, 2023.
American Concrete Institute, 2014, Building Code Requirements for Structural Concrete (ACI 318-14)
and Commentary, dated September.
California Department of Transportation (Caltrans), 2018, Standard Specifications.
California Emergency Management Agency (Cal EMA), California Geological Survey, University of
Southern California, 2009, Tsunami Inundation Map for Emergency Planning, Oceanside and San Luis
Rey Quadrangle, dated June 1.
California Geological Survey (CGS), 2018, Earthquake Fault Zones, A Guide for Government Agencies
Property Owners / Developers, and Geoscience Practitioners for assessing Fault Rupture Hazards in
California, Special Publication 42, Revised 2018.
______, 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication
117A, dated September.
______, 2022a, Tsunami Hazard Area Map, County of San Diego, dated October 7.
______, 2022b, Fault Activity Map of California, https://maps.conservation.ca.gov/cgs/fam/, accessed in
December.
______, 2022c, Earthquake Zones of Required Investigation Website,
https://maps.conservation.ca.gov/cgs/EQZApp/app/, accessed in December.
California State Water Resources Control Board (2022), “GeoTracker,” accessed November.
City of Carlsbad, 2023, Engineering Standards, Volume 5, Carlsbad BMP Design Manual (Post
Construction Treatment BMPS), 2023 Edition, Dated January.
Federal Emergency Management Agency, 2012, FIRM Flood Insurance Rate Map, San Diego County,
Firm Panel 06073C0762G, https://msc.fema.gov/portal/search, effective 05/16/2012; accessed in
November 2022.
Historic Aerials Website, https://www.historicaerials.com/viewer, accessed in January 2023.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
28
International Code Council, 2021, 2022 California Building Code, California Code of Regulations, Title
24, Part 2, Volume 2 of 2, Based on the 2021 International Building Code, Effective 1/1/23.
Kennedy, M.P. and Tan, S.S., 2007, Geologic Map of the Oceanside 30’ x 60’ Quadrangle, California,
California Geological Survey, Regional Geologic Map No. 2, Scale 1:100,000.
NOVA, 2020, Seismic Shear-Wave Survey, Valley Middle School Solar Project, City of Carlsbad,
California.
______, 2023, Geotechnical Investigation, Valley Middle School, Building 900 Modernization, 1645
Magnolia Avenue, Carlsbad, CA, NOVA Project No. 2022253, January 17.
Pasco Laret Suiter & Associates (PLSA), 2022, Precise Grading Plan, Carlsbad Unified School District,
Valley Middle School, 1645 Magnolia Ave., Carlsbad, California 92008, Campus Modernization, 100%
DD Submittal, Sheets C-200 through C-205, Project 3483, December 5.
Public Works Standards, Inc., 2021, “Greenbook” Standard Specifications for Public Works
Construction, 2021 Edition.
Southern California Soil & Testing, Inc. (SCST), 2014, Geotechnical Investigation New Locker/Shower
Building, Valley Middle School Modernization, submitted September 8.
Structural Engineers Association of California (SEAOC), 2022, OSHPD Seismic Design Maps: found
at https://seismicmaps.org/, accessed in December.
United States Geological Survey (USGS), 2022a, USGS Geologic Hazards Science Center, U.S.
Quaternary Faults, accessed in December.
U.S. Department of the Interior, United States Geological Survey (USGS), 1997, San Luis Rey
Quadrangle, California – San Diego Co. 7.5-Minute Series (Topographic), Contour Interval 20 feet,
Scale 1:24,000.
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
PLATES
12
"
T
D
18"
T
D
18
"
T
D
18"
T
D
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXX
G
15"
T
C
18
"
T
C
18
"
T
C
16
"
T
C
16
"
T
C
12"
T
C
10"
T
D
10"
T
D
10"
T
D
10"
T
D
10"
T
D
10"
T
D
10
"
T
D
10
"
T
D
10
"
T
D
16"
T
D
12
"
T
P
12"
T
P
12"
T
P
8"T
D
8"T
D
8"T
D
16"
T
P
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXX
XXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXX
XXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
G
G
G
G
E
E
2"T
D
2"T
D
2"T
D
2"T
D
2"T
D
8"T
D
6"T
D
6"T
D
6"T
D
6"T
D
6"T
D
8"T
P
8"T
P
8"T
P
8"T
P
8"T
D
8"T
D
16
"
T
P
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
G
G
E
6"T
D
12
"
T
D
8"T
D
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
G
G
G
G
E
16
"
T
P
16
"
T
P
12"
T
D
8"T
D
G
16"
T
D
6"T
D
6"T
D
6"T
D
16
"
T
P
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
U
U
U
C
XXXXX
182
182
181
181
180
180
18
0
180
17
9
179
179
179
179
179
179 178
178
178
178
17
8
178
178
178
177
177
177
177
177
177
177
177
176
176
176
176 176
176
176
176
176
17
5
175
175
175
175
175
175
17
5
175
175
175
174
17
4
174
174
174
174
174
174
174
174
174
174
174
174
174
173
173
173
173
173
173
173
173
173
173
173
172
172
172
172
172
172
172
172
172
172
172
171
171
171
17
1
171
171
171
171
171
171
171
170
170
170
170
170
17
0
170
170
170 170
170
169
169
169
169
169
169
169
169
169169
169 16
9
169
169
169
169
169
169
169
169
169
168
16
8 168
168
16
8
168
168
168
168
168
168
168
168
167
167
167
167
167
167
167
167
167
167
167
167
167
167
167
16
6166
166
166
166
166
166
166
166
166166
166
166
165 165
165
165
165 165
165
165
165
165
165
16
4
164
164
164
164
164
164
164
164
164 164
16
4
163
163
163
163
163
163
163
163
163
163
163
16
3
163
163
162
162
162
16
2
162
162
162
162
162
162
162
162
161
161
16
1
161
161
161
161
161
16
1
161
16
1
160
160
16
0
160
160
160
160
160
160
160
159
159
159
159
159
159
159
159
159
159
159
159
158
158
158
158
158
158
158
158
158
158
158
158
158
15
8
158
158
15
8
158
158
158
158
158
158
158
158
158 158
158
157
157
157
157
157
157
157
157
157
157
15
7
15
7
157
156
156
156
156
156
156
15
6
15
6
156
156 156 156
15
5
155
155
155
15
5
155
155
15
5
155
155
155
155
155
15
5
154
154
15
4
15
4
154
15
4
15
4
154
154
154
154
154
153
153153
153
15
3
15
3
15
3
15
3
15
3
152
15
2
152
152
152
152
152
152151151
151
151
151
151
151
150
150
150
150
150
150149
149
149
14814
8
148
148
14
8
M
A
G
N
O
L
I
A
A
V
E
N
U
E
360'
360'
360'
N
6
1
°
5
2
'
5
7
"
E
7
9
9
.
8
5
'
G
G
G
G
G
G
G
G
G
G
G
E
E
E
E
E
E
E
E
UU
18
0
180180
18
0
180
17
5
175
175
175
17
5
17
5
175
175
170
170
170
170
17
0
170
170
165
165
1
6
5
165
165
16
5
160
1
6
0
160
160
160
160
160
160
15
5
155
15
5
15
5
1
5
5
155
15
5
155
155
150
150 150 150
FILE
S911
PRIN
C
I
P
A
L
916
ELEC
T
.
913
OFFI
C
E
902
OFF
I
C
E
903
ELE
C
T
.
904
NUR
S
E
905
WOR
K
R
O
O
M
/
STAF
F
LOU
N
G
E
910
RECE
P
T
I
O
N
901
STO
R
A
G
E
919
STOR
A
G
E
920
ATT
E
N
D
A
N
C
E
912
OFFI
C
E
MAN
A
G
E
R
915
ASS
T
.
PRIN
C
I
P
A
L
914
CONF
E
R
E
N
C
E
917
MEN909WOM
E
N
907
RES
T
R
O
O
M
908
STUD
E
N
T
RES
O
U
R
C
E
918
MA
G
N
O
L
I
A
E
V
E
N
U
E
LIMIT OF
W
O
R
K
LIMIT OF
W
O
R
K
LIMIT OF
W
O
R
K
LIMIT O
F
W
O
R
K
LIM
I
T
O
F
W
O
R
K
LIM
I
T
O
F
W
O
R
K
LIM
I
T
O
F
W
O
R
K
LIM
I
T
O
F
W
O
R
K
LIMIT OF
W
O
R
K
LIMIT OF WORK
LIM
I
T
O
F
W
O
R
K
LIM
I
T
O
F
W
O
R
K
162.80
162.96
165
168
A
A'
B
B'
B-1
P-1
P-2
HA-3
HA-5
HA-2
HA-4P-4
P-3
B-2
B-1
B-2
HA-1
BUILDING 900
PROPOSED
MODERNIZATION
BUILDING 200
BUILDING 300
BUILDING 1200
PROPOSED SHADE
STRUCTURE
PROPOSED SHADE
STRUCTUREPROPOSED CANOPY
LIBRARY
MPR
BUILDING 500
BUILDING 400
BUILDING 600
S-1
PROPOSED ADA RAMPS
WITH RETAINING WALLS
PROPOSED STORMWATER
BMP LOCATION
PROPOSED STORMWATER
BMP LOCATION
FF=169'
FF=163'
L1 FF=150'
L2 FF=163'
FF=158'
0 60'100'
NW
EN
S
4373 Viewridge Avenue, Suite B
San Diego, CA 92123
P: 858.292.7575
944 Calle Amanecer, Suite F
San Clemente, CA 92673
P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
DVBE
www.usa-nova.com
PROJECT NO.:
DATE:
DRAWN BY:
REVIEWED BY:
2022253
FEB 2023
DTJ
MS
GEOTECHNICAL MAP
DRAWING TITLE:
SCALE:1"=60'
PLATE NO.1 OF 2
SBE SDVOSB SLBE
*BASE MAP
Alphastudio Design Group (2023)
VA
L
L
E
Y
M
I
D
D
L
E
S
C
H
O
O
L
CA
M
P
U
S
M
O
D
E
R
N
I
Z
A
T
I
O
N
16
4
5
M
A
G
N
O
L
I
A
A
V
E
N
U
E
CA
R
L
S
B
A
D
,
C
A
9
2
0
0
8
KEY TO SYMBOLS
af FILL
Qop OLD PARALIC DEPOSITS
HAND AUGER BORING
(NOVA, 2023)
HA-5 GEOLOGIC CROSS-SECTIONBB'
GEOTECHNICAL BORING
(NOVA, 2023)
B-2
GEOTECHNICAL BORING
(SCST, 2014)
B-2
SEISMIC SHEAR WAVE
SURVEY, (NOVA, 2020)
S-1
BOREHOLE PERCOLATION
TEST
P-4
PROPOSED FLATWORK
IMPROVEMENT AREAS
'~\ , __
.. .
L.....J
[J
L1 FF=150'
220
100
160
A
0 60 120 180 240 300 420 480 540
220
100
160
A'
El
e
v
a
t
i
o
n
,
f
e
e
t
El
e
v
a
t
i
o
n
,
f
e
e
t
600 660
TD=20'
B-1
TD=20'TD=5'TD=3½'
HA-3
TD=1'
HA-4
TD=20'
B-1
720
BUILDING
900
MPRLIBRARY
(PROJECTED47' WEST)
HA-2
(PROJECTED45' EAST)
(PROJECTED
40' WEST)
B-2(PROJECTED
29' WEST)
(PROJECTED
49' EAST)
Qop Qop
af
PROPOSED
CANOPY
PROPOSED
SHADE
STRUCTURE
PROPOSED
FLATWORK
AREA OF PROPOSED FLATWORK
AND SHADE STRUCTURE
L2 FF=163'FF=163'??????
220
100
160
B
0
El
e
v
a
t
i
o
n
,
f
e
e
t
60 120 180 240 300 360 420
220
100
160
B'
El
e
v
a
t
i
o
n
,
f
e
e
t
TD=2½'
HA-1 TD=5'TD=3½'
HA-2
(PROJECTED
23' NORTH)
HA-3
(PROJECTED
25' SOUTH)
Qop Qop
af af
BUILDING 400
BUILDING 200
PROPOSED
SHADE
STRUCTURE
FF=158'
FF=169'
0 60'120'
4373 Viewridge Avenue, Suite B
San Diego, CA 92123
P: 858.292.7575
944 Calle Amanecer, Suite F
San Clemente, CA 92673
P: 949.388.7710
NOVA
VA
L
L
E
Y
M
I
D
D
L
E
S
C
H
O
O
L
CA
M
P
U
S
M
O
D
E
R
N
I
Z
A
T
I
O
N
16
4
5
M
A
G
N
O
L
I
A
A
V
E
N
U
E
CA
R
L
S
B
A
D
,
C
A
9
2
0
0
8
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
DVBE
www.usa-nova.com
PROJECT NO.:
DATE:
DRAWN BY:
REVIEWED BY:
2022253
FEB 2023
DTJ
MS
GEOLOGIC
CROSS-SECTIONS
DRAWING TITLE:
SCALE:1"=60'
PLATE NO.2 OF 2
SBE SDVOSB SLBE
KEY TO SYMBOLS
af FILL GEOTECHNICAL BORING
(NOVA, 2023)
B-2
Qop OLD PARALIC DEPOSITS HAND AUGER BORING
(NOVA, 2023)
HA-4 GEOLOGIC CONTACT,
QUERIED WHERE UNCERTAIN?
GEOTECHNICAL BORING
(SCST, 2014)
B-2
--
l
1
------
•
1
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
APPENDIX A
USE OF THE GEOTECHNICAL REPORT
Im ortant Information About Your
Geotechnical Engineering Report
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.
The following information is provided to help you manage your risks.
Geotechnical Services Are Performed for
Specific Purposes, Persons, and Projects
Geotechnical engineers structure their services to meet the specific needs of
their clients. A geotechnical engineering study conducted for a civil engi-
neer may not fulfill the needs of a construction contractor or even another
civil engineer. Because each geotechnical engineering study is unique, each
geotechnical engineering report is unique, prepared solelyfor the client. No
one except you should rely on your geotechnical engineering report without
first conferring with the geotechnical engineer who prepared it. And no one
-not even you -should apply the report for any purpose or project
except the one originally contemplated.
Read the Full Report
Serious problems have occurred because those relying on a geotechnical
engineering report did not read it all. Do not rely on an executive summary.
Do not read selected elements only.
A Geotechnical Engineering R~port Is Based on
A Unique Set of Project-Specific Factors
Geotechnical engineers consider a number of unique, project-specific fac-
tors when establishing the scope of a study. Typical factors include: the
client's goals, objectives, and risk management preferences: the general
nature of the structure involved, its size, and configuration: the location of
the structure on the site: and other planned or existing site improvements,
such as access roads, parking lots, and underground utilities. Unless the
geotechnical engineer who conducted the study specifically indicates oth-
erwise, do not rely on a geotechnical engineering report that was:
• not prepared for you,
• not prepared for your project.
• not prepared for the specific site explored, or
• completed before important project changes were made.
Typical changes that can erode the reliability of an existing geotechnical
engineering report include those that affect:
• the function of the proposed structure, as when it's changed from a
parking garage to an office building , or from a light industrial plant
to a refrigerated warehouse,
• elevation, configuration, location, orientation, or weight of the
proposed structure,
• composition of the design team, or
• project ownership.
As a general rule, always inform your geotechnical engineer of project
changes-even minor ones-and request an assessment of their impact.
Geotechnical engineers cannot accept responsibility or liability for problems
that occur because their reports do not consider developments of which
they were not informed
Subsurface Conditions Can Change
A geotechnical engineering report is based on conditions that existed at
the time the study was performed. Do not rely on a geotechnical engineer-
ing reportwhose adequacy may have been affected by: the passage of
time; by man-made events, such as construction on or adjacent to the site;
or by natural events, such as floods, earthquakes, or groundwater fluctua-
tions. Always contact the geotechnical engineer before applying the report
to determine if it is still reliable. A minor amount of additional testing or
analysis could prevent major problems.
Most Geotechnical Findings Are Professional
Opinions
Site exploration identifies subsurface conditions only at those points where
subsurface tests are conducted or samples are taken. Geotechnical engi-
neers review field and laboratory data and then apply their professional
judgment to render an opinion about subsurface conditions throughout the
site. Actual subsurface conditions may differ-sometimes significantly-
from those indicated in your report. Retaining the geotechnical engineer
who developed your report to provide construction observation is the
most effective method of managing the risks associated with unanticipated
conditions.
A Report's Recommendations Are Not Final
Do not overrely on the construction recommendations included in your
report. Those recommendations are not final, because geotechnical engi-
neers develop them principally from judgment and opinion. Geotechnical
engineers can finalize their recommendations only by observing actual
subsurface conditions revealed during construction. The geotechnical
engineer who developed your report cannot assume responsibility or
liability for the report's recommendations if that engineer does not perform
construction observation.
A Geotechnical Engineering Report Is Subject to
Misinterpretation
Other design team members' misinterpretation of geotechnical engineering
reports has resulted in costly problems. Lower that risk by having your geo-
technical engineer confer with appropriate members of the design team after
submitting the report. Also retain your geotechnical engineer to review perti-
nent elements of the design team's plans and specifications. Contractors can
also misinterpret a geotechnical engineering report. Reduce that risk by
having your geotechnical engineer participate in prebid and preconstruction
conferences, and by providing construction observation.
Do Not Redraw the Engineer's Logs
Geotechnical engineers prepare final boring and testing logs based upon
their interpretation of field logs and laboratory data. To prevent errors or
omissions, the logs included in a geotechnical engineering report should
never be redrawn for inclusion in architectural or other design drawings.
Only photographic or electronic reproduction is acceptable, but recognize
that separating logs from the report can elevate risk.
Give Contractors a Complete Report and
Guidance
Some owners and design professionals mistakenly believe they can make
contractors liable for unanticipated subsurface conditions by limiting what
they provide for bid preparation. To help prevent costly problems, give con-
tractors the complete geotechnical engineering report, but preface it with a
clearly written letter of transmittal. In that letter, advise contractors that the
report was not prepared for purposes of bid development and that the
report's accuracy is limited; encourage them to confer with the geotechnical
engineer who prepared the report (a modest fee may be required) and/or to
conduct additional study to obtain the specific types of information they
need or prefer. A prebid conference can also be valuable. Be sure contrac-
tors have sufficient time to perform additional study. Only then might you
be in a position to give contractors the best information available to you,
while requiring them to at least share some of the financial responsibilities
stemming from unanticipated conditions.
Read Responsibility Provisions Closely
Some clients, design professionals, and contractors do not recognize that
geotechnical engineering is far less exact than other engineering disci-
plines. This lack of understanding has created unrealistic expectations that
have led to disappointments, claims, and disputes. To help reduce the risk
of such outcomes, geotechnical engineers commonly include a variety of
explanatory provisions in their reports. Sometimes labeled "limitations"
many of these provisions indicate where geotechnical engineers' responsi-
bilities begin and end, to help others recognize their own responsibilities
and risks. Read these provisions closely Ask questions. Your geotechnical
engineer should respond fully and frankly.
Geoenvironmental Concerns Are Not Covered
The equipment. techniques, and personnel used to perform a geoenviron-
mental study differ significantly from those used to perform a geotechnical
study. For that reason, a geotechnical engineering report does not usually
relate any geoenvironmental findings, conclusions, or recommendations;
e.g., about the likelihood of encountering underground storage tanks or
regulated contaminants. Unanticipated environmental problems have led
to numerous project failures. If you have not yet obtained your own geoen-
vironmental information, ask your geotechnical consultant for risk man-
agement guidance. Do not rely on an environmental report prepared for
someone else.
Obtain Professional Assistance To Deal with Mold
Diverse strategies can be applied during building design, construction,
operation, and maintenance to prevent significant amounts of mold from
growing on indoor surfaces. To be effective, all such strategies should be
devised for the express purpose of mold prevention, integrated into a com-
prehensive plan, and executed with diligent oversight by a professional
mold prevention consultant. Because just a small amount of water or
moisture can lead to the development of severe mold infestations, a num-
ber of mold prevention strategies focus on keeping building surfaces dry.
While groundwater, water infiltration, and similar issues may have been
addressed as part of the geotechnical engineering study whose findings
are conveyed in this report, the geotechnical engineer in charge of this
project is not a mold prevention consultant; none of the services per-
formed in connection with the geotechnical engineer's study
were designed or conducted for the purpose of mold preven-
tion. Proper implementation of the recommendations conveyed
in this report will not of itself be sufficient to prevent mold
from growing in or on the structure involved.
Rely, on Your ASFE-Member Geotechncial
Engineer for Additional Assistance
Membership in ASFE/The Best People on Earth exposes geotechnical
engineers to a wide array of risk management techniques that can be of
genuine benefit for everyone involved with a construction project. Confer
with you ASFE-member geotechnical engineer for more information.
ASFE
The Best People an Earth
8811 Colesville Road/Suite G106, Silver Spring, MD 20910
Telephone: 301/565-2733 Facsimile: 301/589-2017
e-mail: info@asfe.org www.asfe.org
Copyright 2004 by ASFE, Inc. Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly prohibited, except with ASFE'S
specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of ASFE, and only for
purposes of scholarly research or book review. Only members of ASFE may use this document as a complement to or as an element of a geotechnical engineering report. Any other
firm, individual, or other entity that so uses this document without being an ASFE member could be commiling negligent or intentional (fraudulent) misrepresentation.
IIGER06045.0M
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
APPENDIX B
BORING LOGS
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
NOVA BORING LOG
SUBSURFACE EXPLORATION LEGEND
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
SBEDVBE SDVOSB
4373 Viewridge Ave., Suite BSan Diego, CA 92123P: 858.292.7575
www.usa-nova.com
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
MAJOR DIVISIONS TYPICAL NAMES
GRAVEL
MORE THAN HALF
COARSE FRACTION
IS LARGER THAN
NO. 4 SIEVE GRAVEL WITH
15% OR MORE
FINES
CLEAN GRAVEL
WITH LESS THAN
15% FINES
CLEAN SAND
SAND
MORE THAN HALF
COARSE FRACTION
IS FINER THAN NO.
4 SIEVE SIZE
SAND WITH 15%
OR MORE FINES
WITH LESS THAN
15% FINES
SILTS AND CLAYS
LIQUID LIMIT 50% OR LESS
SILTS AND CLAYS
LIQUID LIMIT GREATER THAN 50%
HIGHLY ORGANIC SOILS
GW
GP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PT
WELL-GRADED GRAVEL WITH OR WITHOUT
SAND
POORLY GRADED GRAVEL WITH OR
WITHOUT SAND
SILTY GRAVEL WITH OR WITHOUT SAND
CLAYEY GRAVEL WITH OR WITHOUT SAND
WELL-GRADED SAND WITH OR WITHOUT
GRAVEL
POORLY GRADED SAND WITH OR WITHOUT
GRAVEL
SILTY SAND WITH OR WITHOUT GRAVEL
CLAYEY SAND WITH OR WITHOUT GRAVEL
SILT WITH OR WITHOUT SAND OR
GRAVEL
ELASTIC SILT WITH OR WITHOUT SAND
OR GRAVEL
FAT CLAY WITH OR WITHOUT SAND OR
GRAVEL
ORGANIC SILT OR CLAY OF HIGH
PLASTICITY WITH OR WITHOUT SAND OR
GRAVEL
PEAT AND OTHER HIGHLY ORGANIC SOILS
FI
N
E
-
G
R
A
I
N
E
D
S
O
I
L
S
CO
A
R
S
E
-
G
R
A
I
N
E
D
S
O
I
L
S
MO
R
E
T
H
A
N
H
A
L
F
I
S
F
I
N
E
R
T
H
A
N
N
O
.
2
0
0
S
I
E
V
E
M
O
R
E
T
H
A
N
H
A
L
F
I
S
C
O
A
R
S
E
R
T
H
A
N
N
O
.
2
0
0
S
I
E
V
E
RELATIVE DENSITY OF
COHESIONLESS SOILS
RELATIVE DENSITY
VERY LOOSE
LOOSE
MEDIUM DENSE
DENSE
VERY DENSE
SPT N60
BLOWS/FOOT
0 - 4
4 - 10
10 - 30
30 - 50
OVER 50
CONSISTENCY OF COHESIVE SOILS
CONSISTENCY
VERY SOFT
SOFT
MEDIUM STIFF
STIFF
VERY STIFF
HARD
0 - 2
2 - 4
4 - 8
8 - 15
15 - 30
OVER 30
NUMBER OF BLOWS OF 140 LB HAMMER FALLING 30 INCHES TO DRIVE A 2 INCH O.D.
(1-3/8 INCH I.D.) SPLIT-BARREL SAMPLER THE LAST 12 INCHES OF AN 18-INCH DRIVE
(ASTM-1586 STANDARD PENETRATION TEST).
IF THE SEATING INTERVAL (1st 6 INCH INTERVAL) IS NOT ACHEIVED, N IS REPORTED AS
REF.
0 - 0.25
0.25 - 0.50
0.50 - 1.0
1.0 - 2.0
2.0 - 4.0
OVER 4.0
LEAN CLAY WITH OR WITHOUT SAND
OR GRAVEL
ORGANIC SILT OR CLAY OF LOW TO
MEDIUM PLASTICITY WITH OR
WITHOUT SAND OR GRAVEL
SLBE
SPT N60
BLOWS/FOOT
POCKET PENETROMETER
MEASUREMENT (TSF)
BULK SAMPLE
SPT SAMPLE ( ASTM D1586)
MOD. CAL. SAMPLE (ASTM D3550)
UNRELIABLE BLOW COUNTS
GEOLOGIC CONTACT
SOIL TYPE CHANGE
*
GROUNDWATER / STABILIZED
GROUNDWATER SEEPAGE CORROSIVITY
DIRECT SHEAR
EXPANSION INDEX
MAXIMUM DENSITY
ATTERBERG LIMITS
CONSOLIDATIONCN
CR
DS
EI
MD
LAB TEST ABBREVIATIONS
AL
RESISTANCE VALUERV
SIEVE ANALYSISSA
SAND EQUIVALENTSE
REFUSALREF
LOG ABBREVIATIONS
2 /Y
~
181
IZI
□
-
I I
a I ..
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
2 IN OF GRASS COVER OVER 4 IN OF TOPSOIL
BORING TERMINATED AT 20 FT. NO GROUNDWATER ENCOUNTERED.
OLD PARALIC DEPOSITS (Qop): CLAYEY SANDSTONE; REDDISH BROWN, MOIST, FINE TO
MEDIUM GRAINED, WEAKLY CEMENTED, <5% GRAVEL
REDDISH ORANGE BROWN, DENSE, BLACK MINERALIZATION
WEAKLY TO MODERATELY CEMENTED
SILTY SANDSTONE; REDDISH ORANGE BROWN, MOIST, DENSE, FINE TO MEDIUM GRAINED,
SLIGHTLY MICACEOUS, WEAKLY CEMENTED, BLACK SAND GRAINS
DARK ORANGE BROWN
SA
AL
EI
CR
POORLY GRADED SANDSTONE WITH SILT; DARK REDDISH BROWN, MOIST, VERY DENSE,
FINE TO MEDIUM GRAINED, SLIGHTLY MICACEOUS, WEAKLY CEMENTED, BLACK AND WHITE
MINERALIZATION
POORLY GRADED SANDSTONE; DARK REDDISH BROWN, MOIST, DENSE, MEDIUM GRAINED,
SLIGHTLY MICACEOUS, WEAKLY CEMENTED
ORANGE BROWN
DS
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:ETR~70.6%, N60 ~ 70.60*N~1.18*N
LOGGED BY:
LOG OF BORING B-1
NOV 22, 2022
+163 MSL
N/A
CME 95 HAMMER: 140 LBS., DROP: 30 IN (AUTO)
8-INCH HOLLOW STEM AUGER GN
MS
APPENDIX: B.1
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
PROJECT: 2022253DRAFTED BY: GN
352919
201616
272318
181615
49
43
40
59
x ~------ ---
X
-
-----------------------------------------------------~--
-----------------------------------------------------~--
--------------------------------------------------------
A
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
10 27
SILTY SANDSTONE; MOTTLED ORANGE AND OLIVE GRAYISH BROWN, MOIST, DENSE, FINE
TO MEDIUM GRAINED
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:ETR~80.8%, N60 ~ 80.860*N~1.35*N
LOGGED BY:
LOG OF BORING B-2
JAN 28, 2023
+162 MSL
N/A
CME 75 LAR HAMMER: 35-LBS., DROP: 18-INCH (AUTO)
7-INCH HOLLOW STEM AUGER DTB
MS
APPENDIX: B.2PROJECT: 2022253DRAFTED BY: DTB
BORING TERMINATED AT 20½ FT. NO GROUNDWATER ENCOUNTERED.
FILL (af): CLAYEY SAND; DARK BROWN, MOIST, HAND AUGER ADVANCED WITH LITTLE
EFFORT, FINE TO COARSE GRAINED, SOME ROOTS
SILTY SAND; DARK BROWN, MOIST, HAND AUGER ADVANCED WITH LITTLE EFFORT, FINE TO
COARSE GRAINED, FEW ROOTS
OLD PARALIC DEPOSITS (Qop): SILTY SANDSTONE; REDDISH BROWN, MOIST, HAND
AUGER ADVANCED WITH MODERATE EFFORT, FINE TO COARSE GRAINED
POORLY GRADED SANDSTONE WITH SILT; GRAYISH BROWN, WET, MEDIUM DENSE, FINE TO
COARSE GRAINED
105
14116
201510
16129
34
47
38
CLAYEY SANDSTONE; REDDISH BROWN, MOIST, MEDIUM DENSE, FINE TO MEDIUM GRAINED
DENSE, FINE TO COARSE GRAINED
DARK REDDISH BROWN
SC
SM
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
CR
--------------------------------------------------------
X - - -/_ --------~------ --
-----
z
z
-----------------------------------------------------~--
A
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF HAND AUGER BORING HA-1
JAN 28, 2023
+157½ MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.3PROJECT: 2022253DRAFTED BY: DTB
BORING TERMINATED AT 2½ FT. NO GROUNDWATER ENCOUNTERED.
FILL (af): SILTY SAND; DARK BROWN, MOIST, HAND AUGER ADVANCED WITH LITTLE
EFFORT, FINE TO MEDIUM GRAINED, SOME ROOTS
OLD PARALIC DEPOSITS (Qop): SILTY SANDSTONE; ORANGE BROWN, MOIST, HAND AUGER
ADVANCED WITH MODERATE EFFORT, FINE TO MEDIUM GRAINED
SM
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
EI
-
-
-X
-I~ -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF HAND AUGER BORING HA-2
JAN 28, 2023
+163 MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.4PROJECT: 2022253DRAFTED BY: DTB
BORING TERMINATED AT 5 FT. NO GROUNDWATER ENCOUNTERED.
FILL (af): SILTY SAND; DARK BROWN, MOIST, HAND AUGER ADVANCED WITH LITTLE
EFFORT, FINE TO MEDIUM GRAINED, SOME ROOTS AND DEBRIS
OLD PARALIC DEPOSITS (Qop): SILTY SANDSTONE; MOTTLED ORANGE AND LIGHT
GRAYISH BROWN, MOIST, HAND AUGER ADVANCED WITH MODERATE EFFORT, FINE TO
MEDIUM GRAINED
SM
DARK GRAYISH BROWN
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
-
-
-J
-,
-' --
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF HAND AUGER BORING HA-3
JAN 28, 2023
+166 MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.5PROJECT: 2022253DRAFTED BY: DTB
BORING TERMINATED AT 3½ FT. NO GROUNDWATER ENCOUNTERED.
FILL (af): SILTY SAND; DARK BROWN, MOIST, HAND AUGER ADVANCED WITH LITTLE
EFFORT, FINE TO MEDIUM GRAINED, SOME ROOTS
OLD PARALIC DEPOSITS (Qop): SILTY SANDSTONE; LIGHT REDDISH BROWN, MOIST, HAND
AUGER ADVANCED WITH MODERATE EFFORT, FINE TO MEDIUM GRAINED
SM
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
-
-
-X
--
-
-I~ -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF HAND AUGER BORING HA-4
JAN 28, 2023
+158½ MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.6PROJECT: 2022253DRAFTED BY: DTB
BORING TERMINATED AT 1 FT. NO GROUNDWATER ENCOUNTERED.
FILL (af): POORLY GRADED SAND; LIGHT GRAYISH BROWN, MOIST, HAND AUGER
ADVANCED WITH LITTLE EFFORT, FINE TO COARSE GRAINED
OLD PARALIC DEPOSITS (Qop): CLAYEY SANDSTONE; REDDISH BROWN, MOIST, HAND
AUGER ADVANCED WITH MODERATE EFFORT, FINE TO MEDIUM GRAINED
SP
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
-
-
:::x:
-~ -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF HAND AUGER BORING HA-5
JAN 28, 2023
+167 MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.7PROJECT: 2022253DRAFTED BY: DTB
BORING TERMINATED AT 3½ FT. NO GROUNDWATER ENCOUNTERED.
FILL (af): CLAYEY SAND; GRAYISH BROWN, MOIST, HAND AUGER ADVANCED WITH LITTLE
EFFORT, FINE TO MEDIUM GRAINED, SOME ROOTS
OLD PARALIC DEPOSITS (Qop): SILTY SANDSTONE; REDDISH BROWN, MOIST, HAND
AUGER ADVANCED WITH MODERATE EFFORT, FINE TO MEDIUM GRAINED
SC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
EI
-
-
-~
-I\ -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF PERCOLATION BORING P-1
JAN 28, 2023
+162 MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.8PROJECT: 2022253DRAFTED BY: DTB
FILL (af): SILTY SAND; DARK REDDISH BROWN, MOIST, HAND AUGER ADVANCED WITH
LITTLE EFFORT, FINE TO MEDIUM GRAINED, FEW ROOTS
OLD PARALIC DEPOSITS (Qop): CLAYEY SANDSTONE; ORANGE, MOIST, HAND AUGER
ADVANCED WITH MODERATE EFFORT, FINE TO MEDIUM GRAINED
SM
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
BORING TERMINATED AT 5 FT AND CONVERTED TO A PERCOLATION WELL. NO
GROUNDWATER ENCOUNTERED.
SA
AL
-
-
-
-
-
-X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF PERCOLATION BORING P-2
JAN 28, 2023
+162½ MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.9PROJECT: 2022253DRAFTED BY: DTB
BORING TERMINATED AT 5 FT AND CONVERTED TO A PERCOLATION WELL. NO
GROUNDWATER ENCOUNTERED.
FILL (af): SILTY SAND; DARK REDDISH BROWN, MOIST, HAND AUGER ADVANCED WITH
LITTLE EFFORT, FINE TO MEDIUM GRAINED, FEW ROOTS
OLD PARALIC DEPOSITS (Qop): CLAYEY SANDSTONE; MOTTLED ORANGE WITH MODERATE
AMOUNTS OF GRAY SANDY CLAYSTONE, MOIST, HAND AUGER ADVANCED WITH
MODERATE EFFORT, FINE TO MEDIUM GRAINED
SM
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
-
-
-
-
-
-X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF PERCOLATION BORING P-3
JAN 28, 2023
+161 MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.10PROJECT: 2022253DRAFTED BY: DTB
BORING TERMINATED AT 5 FT AND CONVERTED TO A PERCOLATION WELL. NO
GROUNDWATER ENCOUNTERED.
FILL (af): CLAYEY SAND; DARK BROWN, MOIST, HAND AUGER ADVANCED WITH LITTLE
EFFORT, FINE TO MEDIUM GRAINED, SOME ROOTS
OLD PARALIC DEPOSITS (Qop): CLAYEY SANDSTONE; LIGHT REDDISH BROWN, MOIST,
HAND AUGER ADVANCED WITH MODERATE EFFORT, FINE TO MEDIUM GRAINED
SC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
SA
AL
-
-
-
-
-
-X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
DE
P
T
H
(
F
T
)
N60
BL
O
W
S
P
E
R
F
O
O
T
N
5
10
15
20
25
30
0
BU
L
K
S
A
M
P
L
E
SUMMARY OF SUBSURFACE CONDITIONS
(USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER)
LA
B
T
E
S
T
S
CA
L
/
S
P
T
S
A
M
P
L
E
SOIL DESCRIPTION
MO
I
S
T
U
R
E
(%
)
SO
I
L
C
L
A
S
S
.
(U
S
C
S
)
DR
Y
D
E
N
S
I
T
Y
(p
c
f
)
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
DRILLING EQUPMENT:
ELEVATION (FT):
GROUNDWATER DEPTH (FT):
DRILLING METHOD:
DATE DRILLED:SAMPLE METHOD:
NOTES:REVIEWED BY:N/A
LOGGED BY:
LOG OF PERCOLATION BORING P-4
JAN 28, 2023
+161 MSL
N/A
MANUAL HAND AUGER BULK CUTTINGS
6-INCH HAND AUGER DTB
MS
APPENDIX: B.11PROJECT: 2022253DRAFTED BY: DTB
FILL (af): CLAYEY SAND; DARK BROWN, MOIST, HAND AUGER ADVANCED WITH LITTLE
EFFORT, FINE TO MEDIUM GRAINED, SOME ROOTS
OLD PARALIC DEPOSITS (Qop): POORLY GRADED SANDSTONE WITH SILT; LIGHT REDDISH
BROWN, MOIST, HAND AUGER ADVANCED WITH MODERATE EFFORT, FINE TO MEDIUM
GRAINED
SC
BORING TERMINATED AT 5 FT AND CONVERTED TO A PERCOLATION WELL. NO
GROUNDWATER ENCOUNTERED.
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
-
-
-
-
-
-X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
A
♦ ♦ ♦
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
SCST (2014) BORING LOGS
SUBSURFACE EXPLORATION LEGEND
UNIFIED SOIL CLASSIFICATION CHART
SOIL DESCRIPTION GROUP TYPICAL NAMES SYMBOL
I. COARSE GRAINED, more than 50% of material is larger than No. 200 sieve size.
GRAVELS CLEAN GRAVELS GW Well graded gravels, gravel-sand mixtures, little or no fines More than half of
coarse fraction is GP Poorly graded gravels, gravel sand mixtures, little or no fines. larger than No. 4
sieve size but GRAVELS WITH FINES GM Silty gravels, poorly graded gravel-sand-silt mixtures. smaller than 3". (Appreciable amount of
fines) GC Clayey gravels, poorly graded gravel-sand, clay mixtures.
SANDS CLEAN SANDS SW Well graded sand, gravelly sands, little or no fines. More than half of
coarse fraction is SP Poorly graded sands, gravelly sands, little or no fines. smaller than No.
4 sieve size. SM Silty sands, poorly graded sand and silty mixtures.
SC Clayey sands, poorly graded sand and clay mixtures.
II. FINE GRAINED, more than 50% of material is smaller than No. 200 sieve size.
SIL TS AND CLAYS ML Inorganic silts and very fine sands, rock flour, sandy silt or clayey-silt-
(Liquid Limit less sand mixtures with slight plasticity.
than 50) CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays,
silty clays, lean clays.
OL Organic silts and organic silty clays or low plasticity.
SIL TS AND CLAYS MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils,
(Liquid Limit elastic silts.
greater than 50) CH Inorganic clays of high plasticity, fat clays.
OH Organic clays of medium to high plasticity.
Ill. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils.
FIELD SAMPLE SYMBOLS LABORATORY TEST SYMBOLS
IZ! -Bulk Sample AL -Atterberg Limits
CAL -Modified California penetration test sampler CON -Consolidation
CK -Undisturbed chunk sample COR -Corrosivity Test
MS -Maximum Size of Particle -Sulfate ~a -Water seepage at time of excavation or as indicated -Chloride
-pH and Resistivity
SPT -Standard penetration test sampler OS -Direct Shear
ST -Shelby Tube El -Expansion Index
sz -Water level at time of excavation or as indicated MAX -Maximum Density
RV -RValue
SA -Sieve Analysis
UC -Unconfined Compression
~ NEW SHOWER/LOCKER BUILDING
SOUTHERN CALIFORNIA VALLEY MIDDLE SCHOOL
SOIL & TESTING, INC. By: TBC !Date: 9/8/2014 ---Job Number: 14-0440P3-01 IFigure: 1-1
LOG OF BORING B-1
Date Drilled: 8/21/2014 Logged by: AKN
Equipment: CME-55, 8-inch Hollow Stem Auger Project Manager: TBC
Elevation (ft): 167 Depth to Groundwater (ft): Not Encountered
g
(J') I (.) I-(J') a.. :::> UJ
0
SC
-2
-4
-6
-8
I-
-10
-12
-14
-16
-18
--20
SAMPLES
w CJ.--. z Cl) -<( -~ ~ I-.... ~
Cl) ~ UJ z - 0 0:::: :::s::: Cl) ..., 0 UJ WO "' :::> ...J z SUMMARY OF SUBSURFACE CONDITIONS > :::> 0::: .E I-i:2 co (!) cii (J')
0 z ~ 6 - 0 >-~ -.0 0::: ._,
0
FILL (af)-CLAYEY SAND, orangish brown, fine to medium grained,
X
moist, medium dense.
-OLD PARALIC DEPOSITS {Qo12}-CLAYEY SANDSTONE, orangish
brown and gray, fine to medium grained, moist, very dense, I moderately cemented.
CAL 84 9.4
I \
-
SPT 44 49
CAL 50/3" 9.0
SPT 75 100
BOTTOM OF BORING AT 20 FEET
SOUTHERN CALIFORNIA
SOIL & TESTING, INC.
NEW SHOWER/LOCKER BUILDING
VALLEY MIDDLE SCHOOL
By: TBC Date:
Job Number: 14-0440P3-01 Figure:
13' (J')
~ I-
I-(J')
UJ I I-(!) ~ w ~ 0 I-!::: ~ z :::> 0 cc ~ <(
0 ...J
El
125.3
113.1
9/8/2014
1-2
LOG OF BORING B-2
Date Drilled: 8/21/2014 Logged by: AKN
Equipment: CME-55, 8-inch Hollow Stem Auger Project Manager: TBC
Elevation (ft): 167 Depth to Groundwater (ft): Not Encountered
g
(J') I (.) I-(J') a.. :::> UJ
0
SM
-2
-4
-6
--
-8
I-
-10
-12
-14
-16
-18
--20
SAMPLES
w CJ.--. z Cl) -<( -~ ~ I-.... ~
Cl) ~ UJ z - 0 0:::: :::s::: Cl) ..., 0 UJ WO "' :::> ...J z SUMMARY OF SUBSURFACE CONDITIONS > :::> 0::: .E I-i:2 co (!) cii (J')
0 z ~ 6 - 0 >-~ -.0 0::: ._,
0
FILL (af)-SIL TY SAND, orangish brown, fine to medium grained,
moist, medium dense. I
~
I \
-OLD PARALIC DEPOSITS {Qoe}-SIL TY SANDSTONE, orangish
brown and gray, fine to medium grained, moist, very dense,
moderately cemented. SPT 62 83
-------------------------------------CLAYEY SANDSTONE, orangish brown and gray, fine to medium
\ I grained, moist, very dense, moderately cemented.
CAL I \ 50/5" 12.2
-
SPT 86 115
CAL 50/4" 9.7
BOTTOM OF BORING AT 20 FEET
SOUTHERN CALIFORNIA
SOIL & TESTING, INC.
NEW SHOWER/LOCKER BUILDING
VALLEY MIDDLE SCHOOL
By: TBC Date:
Job Number: 14-0440P3-01 Figure:
13' (J')
~ I-
I-(J')
UJ I I-(!) ~ w ~ 0 I-!::: ~ z :::> 0 cc ~ <(
0 ...J
116.6
120.8
9/8/2014
1-3
Update Geotechnical Report
Valley Middle School Modernization, 1645 Magnolia Avenue, Carlsbad, CA 92008
NOVA Project No. 2022253
February 16, 2023
APPENDIX C
GEOTECHNICAL LABORATORY TESTING
Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested
procedures. Brief descriptions of the tests performed are presented below:
LAB TEST SUMMARY
·CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the
Unified Soils Classification System and are presented on the exploration logs in Appendix B.
·GRADATION ANALYSIS (ASTM D6913): Gradation analyses were performed on representative soil samples in general accordance with ASTM
D422. The grain size distributions of the samples were determined in accordance with ASTM D6913.
·ATTERBERG LIMITS (ASTM D4318): Tests were performed on selected representative fine-grained soil samples to evaluate the liquid limits, plastic
limits, and plasticity indexes in general accordance with ASTM D4318. These test results were utilized to evaluate the soil classification in accordance
with the Unified Soil Classification System.
·EXPANSION INDEX (ASTM D4829): The expansion indexes of selected materials were evaluated in general accordance with ASTM D4829.
Specimens were molded under a specified compactive energy at approximately 50 percent saturation (plus or minus 1 percent). The prepared 1-inch
thick by 4-inch diameter specimens were loaded with a surcharge of 144 pounds per square foot and were inundated with tap water. Readings of
volumetric swell were made for a period of 24 hours.
·CORROSIVITY TEST (CAL. TEST METHOD 417, 422, 643): Soil pH and minimum resistivity tests were performed on representative soil samples in
general accordance with test method CT 643. The sulfate and chloride contents of the selected samples were evaluated in general accordance with
CT 417 and CT 422, respectively.
·DIRECT SHEAR (ASTM D3080): A direct shear test was performed on a relatively undisturbed sample in general accordance with ASTM D3080 to
evaluate the shear strength characteristics of the selected material. The sample was inundated during shearing to represent adverse field conditions.
Soil samples not tested are now stored in our laboratory for future reference and evaluation, if needed. Unless notified to the contrary, samples will be disposed
of 90 days from the date of this report.
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
www.usa-nova.com
SBEDVBE SDVOSB SLBE
FIGURE: C.1PROJECT: 2022253BY: DTB REVIEWED BY: TC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
,, ~--. . •
CLASSIFICATION TEST RESULTS
Gravel Sand
Coarse FineMediumCoarseFine
Silt or Clay
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
www.usa-nova.com
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
SBEDVBE SDVOSB SLBE
Sample Location:
Depth (ft):
USCS Soil Type:
Passing No. 200 (%):
B-1
½ - 2
SC
33
21
11
10
Atterberg Limits (ASTM D4318):
Liquid Limit, LL:
Plastic Limit, PL:
Plasticity Index, PI:
FIGURE: C.2PROJECT: 2022253BY: GN REVIEWED BY: TC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
<E---Size (Inches) -----3,> .::'. U.S. Standard Sieve Sizes ' ,, Hydrometer Analysis ' ,, ..... ,.
0 0 0 0 0 0 0 0
~ ;;r; s: 00 .,. -N .,. <D -N - -
el c:i c:i c:i c:i c:i c:i c:i
1000 z z z z z z
1-w -. I I I I I
I I I ~ I I I
I I I ~ I I
90.0 I I I I I
I I I ·~ I I
I I I I I I
I I I I I, I I
I I I I • I I
80.0 ' I I I I ' I I
I I I I I I
I I I I ~ I I
O') 70.0 I I I I I I
C: ·; ·;;; I I I I I I
1/J I I I I I I I
CV I I I I .~ I I a.. 60.0 1, I I I I I \ I I -I I I I I \ I I C: I I I I I I I Cl)
0 I I I I I It I I ... I I I I I ' I I Cl) 50.0 a.. I I I I I \ I I
I I I I I ' I I
I I I I I ,1 I
40.0 I I I I I I
11 I I I I ~ I
I I I I I ' I
I I I I I I
I I I I I I
30.0 I I I I I
I I I I I
I I I I I
I I I I I 20.0
I I I I I
I I I I I
I I I I I
100 I I I I I
I I I I I
I I I I I
I I I I I
I I I I I
0.0
100 10 1 0.1 0.01 0.001
Grain Size (mm)
I I I I I I I
,, ~--. . .
CLASSIFICATION TEST RESULTS
Gravel Sand
Coarse FineMediumCoarseFine
Silt or Clay
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
www.usa-nova.com
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
SBEDVBE SDVOSB SLBE
Sample Location:
Depth (ft):
USCS Soil Type:
Passing No. 200 (%):
P-1
3½ - 5
SC
32
28
16
12
Atterberg Limits (ASTM D4318):
Liquid Limit, LL:
Plastic Limit, PL:
Plasticity Index, PI:
FIGURE: C.3PROJECT: 2022253BY: DTB REVIEWED BY: TC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
~ Size (Inches) '/ U.S. Standard Sieve Sizes '/ Hydrometer Analysis ' , -/
0 0 ;: 0 0 0 ;: 0
"' '1: s ~ .., N .., <D N
~ ~ <") c:i c:i c:i c:i c:i c:i c:i
100.0 z z z z z z --,, I I I I I
I I I I I I
I I I I I I
90.0 I I I \ I I
I I I I I I
I I I , , I I
I I I I \ I I
I I I I I I
80.0
I I I I \ I I
I I I I I I
I I I I I I
Cl 70.0 I I I I II I I
C: I' I' ·;;; I I I I ' I I
1/) I I I I I I I ca I I I I I I I
Q. 60.0 1, ' I
'E I I I I I \ I I
I I I I I I I Cl) I I I I I I I 0 ... I I I I I \ I I Cl) 50.0 Q. I I I I I \ I I
I I I I I \ I I
I I I I I \. I I
40.0 I I I I I .... I
11 ' ' ' ' ' T' 11
I I I I I I
I I I I I ~1, I
I I I I I
30.0 I I I I I
I I I I I
I I I I I
I I I I I
20.0
I I I I I
I I I I I
I I I I I
10.0 I I I I I
I I I I I
I I I I I
I I I I I
I I I I I
0.0
100 10 1 0.1 0.01 0.001
Grain Size (mm)
I I I I I I I
,, ~--. . .
CLASSIFICATION TEST RESULTS
Gravel Sand
Coarse FineMediumCoarseFine
Silt or Clay
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
www.usa-nova.com
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
SBEDVBE SDVOSB SLBE
Sample Location:
Depth (ft):
USCS Soil Type:
Passing No. 200 (%):
P-3
3½ - 5
SC-SM
27
21
14
7
Atterberg Limits (ASTM D4318):
Liquid Limit, LL:
Plastic Limit, PL:
Plasticity Index, PI:
FIGURE: C.4PROJECT: 2022253BY: DTB REVIEWED BY: TC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
-E---Size (Inches) ,,, U.S. Standard Sieve Sizes ,,, Hydrometer Analysis ' ,, ' ,, ' ,,
0 0 0 0 0 0 0 0
~ ;Ii ~ 00 " -N " <D -N - -
el 0 ~ 0 0 0 0 0
100.0 z z z z z -• I I I I I I
I I I I ~ I I I
I I I I ' I I
90.0 I I I I I I I
I I I I I I I
I I I I I \ I I
I I I I I 4-I I
I I I I I I I
80.0 II
I I I I I I I
I I I I I I I
I I I I I ~ I I
Cl 70.0 I I I I I I I I
C: 'iii I I I I I \ I I
t/J I I I I I I I
n, I I I I I I I
ll. 60.0 1, I I I I ,II I I .... I I I I I \ I I C: I I I I I I I Cl) I I I I I \ I I CJ ... I I I I I • I I Cl) 50.0 ll. I I I I I \ I I
I I I I I \ I I
I I I I I I I
40.0 I I I I I \ I I
11 I I I I I '\ I I
I I I I I ~ I
I I I I I I
I I I I I ' I
30.0 '-
I I I I I ' I I I I I
I I I I I I
I I I I I I 20.0
I I I I I I
I I I I I I
I I I I I I
10.0 I I I I I I
I I I I I I
I I I I I I
I I I I I I
I I I I I I
0.0
100 10 1 0.1 0.01 0.001
Grain Size (mm)
I I I I I I I
,, ~--. . .
LAB TEST RESULTS
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
www.usa-nova.com
944 Calle Amanecer, Suite FSan Clemente, CA 92673
P: 949.388.7710
SBEDVBE SDVOSB
Sample
Location
Expansion
Index
Expansion Index (ASTM D4829)
Sample Depth
(ft.)
Expansion
Potential
SLBE
Expansion
Potential
Classification of Expansive Soil (ASTM D4829)
Expansion
Index
0-20
21-50
51-90
91-130
>130
Very Low
Low
Medium
High
Very High
B-1 0½ - 2 Very Low
FIGURE: C.5PROJECT: 2022253BY: DTB REVIEWED BY: TC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
HA-1 00 - 2½Very Low
HA-5 00 - 3½Very Low
,, ~--. . .
LAB TEST RESULTS
Corrosivity (Cal. Test Method 417,422,643)
Sample
Location
Sample Depth
pH
Resistivity Sulfate Content Chloride Content
(ppm)(%)(Ohm-cm)(ft.)(ppm)(%)
Water-Soluble Sulfate Exposure (ACI 318 Table 19.3.1.1 and Table 19.3.2.1)
Water-Soluble Sulfate (SO4)
in Soil (% by Weight)
Exposure
Class
Cement Type
(ASTM C150)
Exposure
Severity
Max.
W/C
Min. fc'
(psi)
SO4 < 0.10
0.10 ≤ SO4 < 0.20
0.20 ≤ SO4 ≤ 0.20
SO4 > 2.00
N/A
Moderate
Severe
Very Severe
S0
S1
S2
S3
No type restriction
II
V
V plus pozzolan or slag cement
N/A
0.50
0.45
0.45
2,500
4,000
4,500
4,500
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
www.usa-nova.com
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
SBEDVBE SDVOSB SLBE
½ - 2 7.4 1400 130 85 0.0090.013B-1
FIGURE: C.6PROJECT: 2022253BY: DTB REVIEWED BY: TC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
0 - 2½7.4 7400 51 21 0.0020.005B-2
,, ~--. . .
FIGURE: C.7
NOVA
GEOTECHNICAL
MATERIALS
SPECIAL INSPECTION
4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575
www.usa-nova.com
944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710
SBEDVBE SDVOSB SLBE
DIRECT SHEAR TEST RESULTS
PROJECT: 2022253BY: GN REVIEWED BY: TC
VALLEY MIDDLE SCHOOL CAMPUS MODERNIZATION
1645 MAGNOLIA AVENUE
CARLSBAD, CA 92008
7,000
6,000
5,000
..... en .s
CJ) 4,000 CJ) w 0:: I-CJ)
0:: <( 3,000 w
I
CJ)
2,000
1,000
0
0 1,000 2,000 3,000 4,000 5,000 6,000 7,000
NORMAL STRESS (psf)
--Peak --Ultimate
Sample: B-1 @ 6'-6½' Peak Ultimate
<I>' 33 ° 31 °
Description: Old Paralic Deposits (Qop): Silty C' 160 psf 110 psf
Sand
In Situ As Tested
Sample Type: In Situ Yd 106.4 pcf 106.4 pcf
We 9.5 % 18.1 %
Strain Rate: 0.003 in./min.