HomeMy WebLinkAboutSDP 2017-0002; PACIFIC VISTA COMMERCE CENTER BUILDING PADS B & C; INTERIM SOILS REPORT; 2018-02-09References to elevations and locations herein are based on as-graded survey information obtained from
grade checkers' or surveyors' stakes in the field. Geocon Incorporated does not provide surveying
services and, therefore, has no opinion regarding the accuracy of the as-graded elevations or surface
geometry with respect to the approved grading plans or proper surface drainage.
GRADING
Fine grading of the sheet-graded pad consisted ofremoving compacted fill and granitic rock to achieve
finish grade elevations. Due to cut/fill transitions, the cut portions of the pads (and shallow fill areas)
were overexcavated at least 5 feet below finish grade. The lateral limits of the overexcavation
extended at least 5 feet outside the building footprints. Prior to placing fill, the ground surface was
scarified, if practical, moisture conditioned, and compacted prior to receiving fill. Grading consisted of
maximum cuts and fills of approximately 10 feet and 15 feet, respectively.
The grading was performed in conjunction with testing and observation services provided by Geocon
Incorporated. Fill soils derived from on-site and imported excavations were placed and compacted in
layers until the design elevations were attained.
Fill Materials and Placement Procedures
The on-site fill materials generally consisted of silty sands with gravel, cobble, and boulder sized rock
fragments. The oversize rock hold-down restrictions presented in our referenced report were modified
by Ryan Companies as discussed in Section 1.0 Conclusions and Recommendations. The fills were
placed in lifts no thicker than would allow for adequate bonding and compaction. The soil was
moisture conditioned as necessary and mixed during placement.
Field In-Place Density and Laboratory Testing
During the grading operation, compaction procedures were observed and in-place density tests were
performed to evaluate the relative compaction of the fill material. The in-place density tests were
performed in general conformance with ASTM Test Method D 6938 (nuclear). Results of the field
density tests and moisture content tests performed during grading have been summarized on Table I.
In general, the in-place density test results indicate that the fill, at the locations tested, has a relative
compaction of at least 90 percent.
Laboratory tests were performed on samples of materials used for fill to evaluate moisture-density
relationships, optimum moisture content and maximum dry density (ASTM D 1557). Additionally,
laboratory tests were performed on samples to determine the expansion potential (ASTM D 4829) and
the water-soluble sulfate content (California Test Method No. 417). The results of the laboratory tests
are summarized on Tables II through V.
Project No. 06442-32-28A -2 -February 9, 2018
Finish Grade Soil Conditions
Observations and laboratory test results indicate that the prevailing soils within 3 feet of finish grade
of the building pads have Expansion Index (El's) of zero and are considered to be "non-expansive"
(expansion index [EI] of 20 or less) as defined by 2016 California Building Code (CBC)
Section 1803.5.3 (see Table 1). Table V presents a summary of the expansion classification for the
prevailing finish grade soils on each lot.
TABLE 1
EXPANSION CLASSIFICATION BASED ON EXPANSION INDEX
Expansion Index (EI) Expansion Classification 2016 CBC
Expansion Classification
0-20 Very Low Non-Expansive
21 -50 Low
51-90 Medium
91 -130 High
Expansive
Greater Than 13 0 Very High
We performed laboratory tests on samples of the site materials to evaluate the percentage of water-
soluble sulfate. Results from the laboratory water-soluble sulfate content testing are presented in
TableIV and indicate that the on-site materials at the locations tested possess a "Not Applicable" and
"SO" sulfate exposure to concrete structures as defined by 2016 CBC Section 1904 and ACI 318-14
Chapter 19. The CBC provides no specific recommendations for concrete subjected to "not
applicable" sulfate exposure. It should be noted that the presence of water-soluble sulfates is not a
visually discernible characteristic; therefore, other soil samples from the site could yield different
concentrations. Additionally, over time landscaping activities (i.e. addition of fertilizers and other soil
nutrients) may affect the concentration.
Geocon Incorporated does not practice m the field of corrosion engineering. Therefore, it is
recommended that further evaluation by a corrosion engineer be performed if improvements are
planned that are susceptible to corrosion.
SOIL AND GEOLOGIC CONDITIONS
The soil and geologic conditions encountered during grading were found to be generally similar to
those described in the referenced geotechnical report.
Project No. 06442-32-28A -3 -February 9, 2018
CONCLUSIONS AND RECOMMENDATIONS
1.0 General
1.1 Based on observations and test results, it is the opinion of Geocon Incorporated that the
grading within the structure footprints on the subject building pads has been performed in
substantial conformance with the recommendations of the referenced project soil report. Soil
and geologic conditions encountered during grading which differ from those anticipated by
the project soil report are not uncommon. Where such conditions required a significant
modification to the recommendations of the project soil reports, they have been described
herein.
1.2 During grading, Ryan Companies revised the rock size placement criteria to:
• Rock fragments greater than 6 inches in maximum dimension should not be placed
within one foot of finish grade.
• Rock Fragments greater than 14 inches in maximum dimension should not be placed
within ten feet of finish grade.
1.3 Based on our observations during grading, the original rock hold-down restrictions were not
strictly followed. Ryan Company representatives were made aware of the grading
contractor's inability to adhere to these restrictions and Geocon was informed that any
future impacts to subcontractors resulting from the oversize materials would be managed by
the Ryan Companies. The presence of over-size rock in the upper portions of the
embankments however should not adversely affect the performance of the compacted fill.
2.0 Future Grading and Improvements
2.1 Additional grading or planned improvements performed at the site should be accomplished
in conjunction with our geotechnical services. Plans for any future improvements should be
reviewed by Geocon Incorporated prior to finalizing. Any additional trench backfill in
excess of I-foot-thick should be compacted to at least 90 percent relative compaction.
This office should be notified at least 48 hours prior to commencing additional grading or
backfill operations.
3.0 Seismic Design Criteria
3.1 We used the computer program US. Seismic Design. Maps, provided by the USGS. Table 3
summarizes site-specific design criteria obtained from the 2016 California Building Code
(CBC; Based on the 2015 International Building Code [IBC) and ASCE 7-10), Chapter 16
Structural Design, Section 1613 Earthquake Loads. The short spectral response uses a period of
0.2 seconds. The values presented in Table 3 are for the risk-targeted maximum considered
Project No. 06442-32-28A -4 -February 9, 2018
earthquake (MCfa). Based on soil conditions and planned grading, Buildings B and C may be
designed using Site Class D. We evaluated the Site Class based on the discussion in
Section 1613.3.2 of the 2016 CBC and Table 20.3-1 of ASCE 7-10.
TABLE 3
2016 CBC SEISMIC DESIGN PARAMETERS
Parameter Value 2016 CBC
Reference
Site Class D Section 1613.3.2
Spectral Response -Class B (0.2 sec), Ss 1.039 g Figure I 613.3.1 (1)
Spectral Response -Class B (I sec), S1 0.404 g Figure 1613.3.1(2)
Site Coefficient, Fa 1.084 Table 1613.3.3(1)
Site Coefficient, Fv 1.596 Table 1613.3.3(2)
Maximum Considered Earthquake 1.127 g Section 1613.3.3 (Eqn 16-37) Spectral Response Acceleration (0.2 sec), SMs
Maximum Considered Earthquake 0.644 g Section 1613.3.3 (Eqn 16-38) Spectral Response Acceleration (1 sec), SM1
5% Damped Design 0.751 g Section 1613.3.4 (Eqn 16-39) Spectral Response Acceleration (0.2 sec), Sos
5% Damped Design 0.430 g Section 1613.3.4 (Eqn 16-40) Spectral Response Acceleration (1 sec), Soi
3 .2 Conformance to the criteria for se1sm1c design does not constitute any guarantee or
assurance that significant structural damage or ground failure will not occur in the event of a
maximum level earthquake. The primary goal of seismic design is to protect life and not to
avoid all damage, since such design may be economically prohibitive.
4.0 Foundation and Concrete Slab-On-Grade Recommendations
4.1 The project is suitable for the use of continuous strip footings, isolated spread footings, or
appropriate combinations thereof, provided the preceding grading recommendations are
followed.
4.2 The following recommendations are for the planned structures and assume that the
foundation systems for the structures will bear on properly compacted fill.
Buildings B and C: continuous footings should be at least 12 inches wide and should
extend at least 24 inches below lowest adjacent pad grade. Isolated spread footings should
be at least two feet square and extend a minimum of 24 inches below lowest adjacent pad
grade.
Project No. 06442-32-28A -5 -February 9, 2018
4.3 Isolated footings, which are located beyond the perimeter of the buildings and support
structural elements connected to the building, should be connected to the building
foundation system with grade beams.
4.4 The project structural engmeer should design the reinforcement for the footings. For
continuous footings, however, we recommend minimum reinforcement consisting of four
No. 5 steel reinforcing bars, two placed near the top of the footing and two placed near the
bottom. The project structural engineer should design reinforcement of isolated spread
footings.
4.5 The recommended allowable bearing capacity for foundations designed as recommended
above is 2,500 pounds per square foot (pst) for foundations in properly compacted fill soil.
This soil bearing pressure may be increased by 300 psf and 500 psf for each additional foot
of foundation width and depth, respectively, up to a maximum allowable soil bearing of
4,000 psf.
4.6 The allowable bearing pressures recommended above are for dead plus live loads only and
may be increased by up to one-third when considering transient loads such as those due to
wind or seismic forces.
4. 7 The estimated maximum total and differential settlement for the planned structures due to
foundation loads is 1 inch and ¾ inch, respectively over a span of 40 feet.
4.8 Building interior concrete slabs-on-grade should be at least five inches in thickness. Slab
reinforcement should consist of No. 3 steel reinforcing bars spaced 18 inches on center in
both directions placed at the middle of the slab. If the slabs will be subjected to heavy loads,
consideration should be given to increasing the slab thickness and reinforcement. The
project structural engineer should design interior concrete slabs-on-grade that will be
subjected to heavy loading (i.e., fork lift, heavy storage areas). Subgrade soils supporting
heavy loaded slabs should be compacted to at least 95 percent relative compaction.
4.9 A vapor retarder should underlie slabs that may receive moisture-sensitive floor coverings
or may be used to store moisture-sensitive materials. The vapor retarder design should be
consistent with the guidelines presented in the American Concrete Institute's (ACI) Guide
for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials (ACI 302.2R-06). In
addition, the membrane should be installed in a manner that prevents puncture in accordance
with manufacturer's recommendations and ASTM requirements. The project architect or
developer should specify the type of vapor retarder used based on the type of floor covering
that will be installed and if the structure will possess a humidity-controlled environment.
Project No. 06442-32-28A - 6 -February 9, 20 I 8
4.10 The project foundation engineer, architect, and/or developer should determine the thickness
of bedding sand below the slab. Typically, 3 to 4 inches of sand bedding is used in the San
Diego County area. Geocon should be contacted to provide recommendations if the bedding
sand is thicker than 6 inches.
4.11 Exterior slabs not subject to vehicle loads should be at least 4 inches thick and reinforced
with 6x6-W2.9/W2.9 (6x6-6/6) welded wire mesh or No. 3 reinforcing bars spaced at
24 inches on center in both directions to reduce the potential for cracking. The mesh should
be placed in the middle of the slab. Proper mesh positioning is critical to future performance
of the slabs. The contractor should take extra measures to provide proper mesh placement.
Prior to construction of slabs, the subgrade should be moisture conditioned to at least
optimum moisture content and compacted to a dry density of at least 90 percent of the
laboratory maximum dry density in accordance with ASTM 1557.
4.12 To control the location and spread of concrete shrinkage and/or expansion cracks, it is
recommended that crack-control joints be included in the design of concrete slabs. Crack-
control joint spacing should not exceed, in feet, twice the recommended slab thickness in
inches ( e.g., 10 feet by 10 feet for a 5-inch-thick slab). Crack-control joints should be
created while the concrete is still fresh using a grooving tool or shortly thereafter using saw
cuts. The structural engineer should take criteria of the American Concrete Institute into
consideration when establishing crack-control spacing patterns.
4.13 The above foundation and slab-on-grade dimensions and mm1mum reinforcement
recommendations are based upon soil conditions only, and are not intended to be used in
lieu of those required for structural purposes. The project structural engineer should design
actual concrete reinforcement.
4.14 No special subgrade presaturation is deemed necessary prior to placement of concrete.
However, the slab and foundation subgrade should be moisture conditioned as necessary to
maintain a moist condition as would be expected in any concrete placement.
4.15 The recommendations of this report are intended to reduce the potential for cracking of slabs
due to expansive soil (if present), differential settlement of existing soil or soil with varying
thicknesses. However, even with the incorporation of the recommendations presented
herein, foundations, stucco walls, and slabs-on-grade placed on such conditions may still
exhibit some cracking due to soil movement and/or shrinkage. The occurrence of concrete
shrinkage cracks is independent of the supporting soil characteristics. Their occurrence may
be reduced and/or controlled by limiting the slump of the concrete, proper concrete
Project No. 06442-32-28A - 7 -February 9, 2018
placement and curing, and by the placement of crack control joints at periodic intervals, in
particular, where re-entrant slab comers occur.
4.16 A representative of Geocon Incorporated should observe the foundation excavations prior to
the placement of reinforcing steel or concrete to check that the exposed soil conditions are
consistent with those anticipated. If unanticipated soil conditions are encountered,
foundation modifications may be required.
4.17 Geocon Incorporated should be consulted to provide additional design parameters as
required by the structural engineer.
5.0 Lateral Loading
5.1 To resist lateral loads, a passive earth pressure equivalent to a fluid with a density of
300 pounds per cubic foot (pd) should be used for design of footings or shear keys poured
neat against properly compacted granular fill soils or undisturbed formational material. The
passive pressure assumes that a horizontal ground surface extends away from the base of the
wall at least five feet or three times the depth of the surface generating the passive pressure,
whichever is greater. The upper 12 inches of material in areas not protected by floor slabs or
pavement should not be included in design for passive resistance.
5.2 If friction is to be used to resist lateral loads, an allowable coefficient of friction between
soil and concrete of 0.35 should be used for design for footings founded in compacted fill.
The recommended passive pressure may be used concurrently with frictional resistance
without reduction and may be increased by one-third for transient wind or seismic loading.
6.0 Retaining Walls
6.1 Retaining walls not restrained at the top and having a level backfill surface should be
designed for an active soil pressure equivalent to the pressure exerted by a fluid with a
density of 35 pounds per cubic foot (pcf). Where the backfill will be inclined at 2: I
(horizontal:vertical), an active soil pressure of 50 pcf is recommended. These soil pressures
assume that the backfill materials within an area bounded by the wall and a 1: 1 plane
extending upward from the base of the wall possess an Expansion Index less than 50.
Imported low expansion granular soil would be required.
6.2 If moderately expansive soils (EI greater than 50) are used for backfill, the active earth
pressure would increase to 80 pcf for level backfill and 95 pcf for backfill inclined at 2: I
(horizontal:vertical). These soil pressures assume that the backfill materials within an area
bounded by the wall and a 1: I plane extending upward from the base of the wall possess an
Project No. 06442-32-28A -8 -February 9, 2018
Expansion Index less than 130. Backfill material exhibiting an Expansion Index greater than
130 should not be used.
6.3 Retaining walls shall be designed to ensure stability against overturning sliding, excessive
foundation pressure and water uplift. Where a keyway is extended below the wall base with
the intent to engage passive pressure and enhance sliding stability, it is not necessary to
consider active pressure on the keyway.
6.4 Where walls are restrained from movement at the top, an additional uniform pressure of
8H psf (where H equals the height of the retaining wall portion of the wall in feet) should be
added to the active soil pressure where the wall possesses a height of 8 feet or less and 12H
where the wall is greater than 8 feet. For retaining walls subject to vehicular loads within a
horizontal distance equal to two-thirds the wall height, a surcharge equivalent to two feet of
fill soil should be added (total unit weight of soil should be taken as 130 pct).
6.5 Soil contemplated for use as retaining wall backfill, including import materials, should be
identified in the field prior to backfill. At that time Geocon Incorporated should obtain
samples for laboratory testing to evaluate its suitability. Modified lateral earth pressures may
be necessary if the backfill soil does not meet the required expansion index or shear
strength. City or regional standard wall designs, if used, are based on a specific active lateral
earth pressure and/or soil friction angle. In this regard, on-site soil to be used as backfill may
or may not meet the values for standard wall designs. Geocon Incorporated should be
consulted to assess the suitability of the on-site soil for use as wall backfill if standard wall
designs will be used.
6.6 Unrestrained walls will move laterally when backfilled and loading is applied. The amount
of lateral deflection is dependent on the wall height, the type of soil used for backfill, and
loads acting on the wall. The wall designer should provide appropriate lateral deflection
quantities for planned retaining walls structures, if applicable. These lateral values should be
considered when planning types of improvements above retaining wall structures.
6.7 Retaining walls should be provided with a drainage system adequate to prevent the buildup
of hydrostatic forces and should be waterproofed as required by the project architect. The
use of drainage openings through the base of the wall (weep holes) is not recommended
where the seepage could be a nuisance or otherwise adversely affect the property adjacent to
the base of the wall. If conditions different than those described are expected, or if specific
drainage details are desired, Geocon Incorporated should be contacted for additional
recommendations.
Project No. 06442-32-28A - 9 -February 9, 2018
6.8 In general, wall foundations having a minimum depth of 24 inches and width of 12 inches
may be designed for an allowable soil bearing pressure of 2,000 psf. The recommended
allowable soil bearing pressure may be increased by 300 psf and 500 psf for each additional
foot of foundation width and depth, respectively, up to a maximum allowable soil bearing
pressure of 4,000 psf.
6.9 The proximity of the foundation to the top of a slope steeper than 3: 1 could impact the
allowable soil bearing pressure. Therefore, Geocon Incorporated should be consulted where
such a condition is anticipated. As a minimum, wall footings should be deepened such that
the bottom outside edge of the footing is at least seven feet from the face of slope when
located adjacent and/or at the top of descending slopes.
6.10 The structural engineer should determine the Seismic Design Category for the project in
accordance with Section 1613.3.5 of the 2016 CBC or Section 11.6 of ASCE 7-10. For
structures assigned to Seismic Design Category of D, E, or F, retaining walls that support
more than 6 feet of backfill should be designed with seismic lateral pressure in accordance
with Section 1803.5.12 of the 2016 CBC. The seismic load is dependent on the retained
height where His the height of the wall, in feet, and the calculated loads result in pounds per
square foot (psf) exerted at the base of the wall and zero at the top of the wall. A seismic
load of 21H should be used for design. We used the peak ground acceleration adjusted for
Site Class effects, PGAM, of 0.438g calculated from ASCE 7-10 Section 11.8.3 and applied
a pseudo-static coefficient of 0.33.
6.11 If conditions different than those described are anticipated, or if specific drainage details are
desired, Geocon Incorporated should be contacted for additional recommendations. If on-
site highly expansive soils are used as retaining wall backfill, modifications to the design
parameters provided above would be required.
7.0 Mechanically Stabilized Earth (MSE) Retaining Walls
7.1 We are providing geotechnical parameters for mechanically stabilized earth (MSE)
reinforced retaining walls that are being considered for the project. Geogrid retaining walls
are alternative walls that consist of modular block facing units with geogrid reinforced earth
behind the block. The geogrid attaches to the block units and is typically placed at specified
vertical intervals and embedment lengths. Spacing and lengths are based on the wall height
and type of soil used for backfill.
7.2 For design of MSE retaining walls, we recommend an active soil pressure equivalent to the
pressure exerted by a fluid density of 35 pound per cubic foot (pct) for level backfill. Where
Project No. 06442-32-28A February 9, 2018
the backfill will be inclined at 2: 1 (horizontal:vertical), an active soil pressure of 50 pcf is
recommended. Expansive soil should not be used as backfill material behind retaining walls.
Soil placed for retaining wall backfill should have an Expansion Index~ 50 and should meet
the geotechnical parameters listed in Table 7.
TABLE 7
GEOTECHNICAL PARAMETERS FOR GEOSYNTHETIC REINFORCED WALLS
Parameter Reinforced Zone Retained Zone Foundation Zone
Angle oflnternal Friction 30 degrees 30 degrees 30 degrees
Cohesion 0 psf 0 psf 0 psf
Wet Unit Weight 130 pcf 130 pcf 130 pcf
Notes:
Reinforced Zone is the area where geotextile reinforcing grid is placed.
Retained Zone is the area behind the reinforced zone and within a 1: 1 plane extending up and out from
the bottom of the reinforced zone to a horizontal distance equal to the height of the retaining wall.
Foundation Zone is the area below the reinforced zone and within a 1: I plane extending down and
out from the bottom of the wall block.
7.3 Based on previous laboratory testing, the on-site soils should meet the soil properties listed
in Table 7 and soil properties specified by the wall engineer. Laboratory testing should be
performed on samples of the proposed soils to check if the shear strength of the soil meets
the design values and additional soil specifications required by the wall engineer. Results, if
they vary significantly from those in Table 7, should be provided to the wall designer for his
review and determination if modifications to the design are warranted. The designer should
re-evaluate stability of the walls based on the shear strength test results.
7.4 An allowable soil bearing pressure of 2,500 pounds per square foot (psf) can be used for
foundation design and calculations for wall bearing. This bearing pressure assumes a
minimum foundation width and depth of 12 inches. The allowable soil bearing pressure may
be increased by 300 psf and 500 psf for each additional foot of foundation width and depth,
respectively, up to a maximum allowable soil-bearing pressure of 4,000 psf. The foundation
bearing zone of the wall can be considered across the reinforced zone of the wan.
7.5 The bearing pressure may be increased by one-third for transient loads due to wind or
seismic forces.
7.6 The proximity of the foundation to the top of a slope steeper than 3: 1 could impact the
allowable soil bearing pressure. As a minimum, wall footings should be deepened such that
the bottom outside edge of the footing is at least seven feet from the face of slope when
located adjacent and/or at the top of descending slopes.
Project No. 06442-32-28A -11 -February 9, 2018
7. 7 Soil placed within the reinforced zone of the wall should be compacted to at least 90 percent
of the laboratory maximum dry density at or slightly above optimum moisture content. This
is applicable to the entire embedment width of the geogrid reinforcement. Typically, wall
designers specify no heavy compaction equipment within three feet of the face of the wall to
reduce the potential for wall deformation during construction. However, smaller equipment
(e.g., walk-behind, self-driven compactors or hand whackers) can be used to compact the
materials without causing deformation of the wall. If the designer specifies no compaction
effort for this zone, then the uncompacted soil does not meet the minimum shear strength
(angle of internal friction) presented in Table 7 and this portion of geogrid should not be
relied upon for reinforcement, and overall embedment lengths will have to be increased to
account for the difference.
7.8 The wall should be provided with a drainage system sufficient enough to prevent excessive
seepage through the wall and water at the base of the wall to prevent hydrostatic pressures
behind the wall.
7.9 Geosynthetic reinforcement must elongate to develop full tensile resistance. This elongation
generally results in movement at the top of the wall. The amount of movement is dependent
upon the height of the wall (e.g., higher walls rotate more) and the type of geogrid
reinforcing used. In addition, over time geogrid has been known to exhibit creep (sometimes
as much as 5 percent) and can undergo additional movement. Given this condition,
structures and pavement placed within the reinforced and retained zones of the wall might
undergo movement. Planned buildings and settlement sensitive improvements should not be
placed within the reinforced and retained zones of the wall.
8.0 Slope Maintenance
8.1 Slopes that are steeper than 3: I (horizontal:vertical) may, under conditions which are both
difficult to prevent and predict, be susceptible to near surface slope instability. The
instability is typically limited to the outer three feet of a portion of the slope and does not
directly impact the improvements on the pad areas above or below the slope. The
occurrence of surficial instability is more prevalent on fill slopes and is usually preceded by
a period of heavy rainfall, excessive irrigation, or the migration of subsurface seepage. The
disturbance and/or loosening of the surficial soils, as might result from root growth, soil
expansion, or excavation for irrigation lines and slope planting, may also be a significant
contributing factor for surficial instability. It is, therefore, recommended that, to the
maximum extent practical (a) disturbed/loosened surficial soils be either removed or
properly recompacted, (b) irrigation systems be periodically inspected and maintained to
eliminate leaks and excessive irrigation, and (c) surface drains on, and adjacent to, slopes
should be periodically maintained to preclude ponding or erosion. It should be noted that
Project No. 06442-32-28A -12 -February 9, 2018
although the incorporation of the above recommendations should reduce the potential for
surficial slope instability, it will not eliminate the possibility, and, therefore, it may be
necessary to rebuild or repair a portion of the project's slopes in the future.
9.0 Site Drainage and Moisture Protection
9.1 Adequate site drainage is critical to reduce the potential for differential soil movement,
erosion and subsurface seepage. Under no circumstances should water be allowed to pond
adjacent to footings. The site should be graded and maintained such that surface drainage is
directed away from structures in accordance with 2016 CBC 1804.4 or other applicable
standards. In addition, surface drainage should be directed away from the top of slopes into
swales or other controlled drainage devices. Roof and pavement drainage should be directed
into conduits that carry runoff away from the proposed structure.
9.2 Underground utilities should be leak free. Utility and irrigation lines should be checked
periodically for leaks, and detected leaks should be repaired promptly. Detrimental soil
movement could occur if water is allowed to infiltrate the soil for prolonged periods of time.
LIMITATIONS
The conclusions and recommendations contained herein apply only to our work with respect to
grading and represent conditions at the date of our final observation on February 9, 2018. Changes in
the conditions of a property can occur with the passage of time due to natural processes or the works
of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may
occur, resulting from legislation or the broadening of knowledge in the fields of geotechnical
engineering or geology. Accordingly, the findings of this report may be invalidated wholly or partially
by changes outside our control. Therefore, this report is subject to review and should not be relied
upon after a period of three years. Any subsequent grading should be done in conjunction with our
observation and testing services.
As used herein, the term "observation" implies only that we observed the progress of the work with
which we agreed to be involved. Our services did not include the evaluation or identification of the
potential presence of hazardous or corrosive materials. Our conclusions and opinions as to whether the
work essentially complies with the job specifications are based on our observations, experience and
test results. Due to the inaccuracies inherent in most field and laboratory soil tests, and the necessary
assumption that the relatively small soil sample tested is representative of a significantly larger volume
of soil, future tests of the same soil, location or condition should not be expected to duplicate specific
individual test results of this report. Subsurface conditions, and the accuracy of tests used to measure
such conditions, can vary greatly at any time. We make no warranty, express or implied, except that
Project No. 06442-32-28A -13 -February 9, 2018
I
0GEOCON
TABLE 1
SUMMARY OF FIELD DENSITY TEST RESULTS
Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-:
Elev. >¾" Max. Opt. Field Field Relative Test No. Date Curve Dry Moist Dry Moisture (MM/DD Location or Rock Compaction Depth No. Density Content Density Content /YY) (feet) (%) (pct) (%) (pct) (%) (%)
Pre. No. Re.
I 11 /28/17 E Building C 378 12 0 132.5 9.8 116.4 3.3 88
I A 11 /29/17 E Building C 378 12 0 132.5 9.8 118 .1 5.2 89
1 B 11 /30/17 E Building C 378 12 0 132.5 9.8 122.1 I 1.0 92
2 11 /29/17 E Driveway E 382 12 0 132.5 9.8 118.5 5.3 89
2 A 11 /30/17 E Driveway E 382 12 0 132.5 9.8 122.8 10.9 93
3 12/01/17 E Building C 379 4 0 134.9 7.4 124.5 8.7 92
4 12/01/17 E Building C 378 4 0 134.9 7.4 119.8 4.0 89
4 R 12t'Q4ff7 .g Eh1i!Eliflg G J.+& 4 Q ~ +A +2-M &..J &9
5 12/04/17 E Building C 381 4 0 134.9 7.4 125.0 8.8 93
6 12/04/17 E building C 380 4 0 134.9 7.4 126.1 9.1 93
7 12/04/17 E Building C 379 4 0 134.9 7.4 125.6 8.9 93
8 12/04/17 E Building C 380 4 0 134.9 7.4 124.6 8.5 92
9 12/05/17 E Building C 381 4 0 134.9 7.4 126.1 8.5 93
10 12/05/17 E Building C 380 4 0 134.9 7.4 123.5 9.3 92
11 12/07/17 E Building C 383 4 0 134.9 7.4 128.4 8.6 95
12 12/07/17 E Building C 382 4 0 134.9 7.4 127.0 8.9 94
13 12/07/17 E Building C 382 4 0 134.9 7.4 127.1 8.8 94
14 12/08/17 w Building C 386 4 0 134.9 7.4 118.4 4.4 88
14 A 12/11/17 w Building C 386 4 0 134.9 7.4 123.6 9.1 92
15 12/08/17 w Building C 385 4 0 134.9 7.4 120.5 5.1 89
15 A 12/11 /17 w Building C 385 4 0 134.9 7.4 122.4 9.4 91
16 12/11/17 w Building C 388 4 0 134.9 7.4 124.7 9.2 92
17 12/11/17 w Building C 386 4 0 134.9 7.4 126.6 8.5 94
18 12/12/17 w Building C 386 4 0 134.9 7.4 123.7 9.3 92
19 12/12/17 w Building C 386 4 0 134.9 7.4 122.3 8.5 91
20 12/12/17 E Building C 384 4 0 134.9 7.4 124.4 8.8 92
21 12/13/17 w Building C 387 4 0 134.9 7.4 122.2 8.6 91
22 12/13/17 w Building C 385 4 0 134.9 7.4 125.1 10.4 93
23 12/13/17 E Building C 384 4 0 134.9 7.4 126.4 8.4 94
24 12/13/17 E Building C 383 4 0 134.9 7.4 123.7 9.1 92
I I \
~GEOCON
TABLE 1
SUMMARY OF FIELD DENSITY TEST RESULTS
Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-:
Date Elev. >¾" Max. Opt. Field Field Relative Test No. or Curve Dry Moist Dry Moisture (MM/DD Location Depth No. Rock Density Content Density Content Compaction
/YY) (%) (%)
Pre. No. Re. (feet) (pct) (%) (pct) (%)
~ R l~il4ff7 g Qrive:way-F'. ~ 4 Q H4,9 M +-l-8--d 6.,6 &&
26 12/15/17 SE Building C 375 4 0 134.9 7.4 124.1 8.1 92
27 12/15/17 SE Building C 376 4 0 134.9 7.4 118.4 5.5 88
27 A 12/15/17 SE Building C 376 4 0 134.9 7.4 122.9 7.8 91
28 12/15/17 SE Building C 377 4 0 134.9 7.4 120.0 6.1 89
28 A 12/15/17 SE Building C 377 4 0 134.9 7.4 124.5 8.3 92
29 12/15/17 s Building C 378 4 0 134.9 7.4 121.9 8.0 90
30 12/15/17 s Building C 380 4 0 134.9 7.4 125.2 8.7 93
31 12/18/17 E Driveway F 377 4 0 134.9 7.4 120.6 4.3 89
31 A 12/18/17 E Driveway F 377 4 0 134.9 7.4 124.4 8.9 92
32 12/18/17 SE Building C 383 4 0 134.9 7.4 125.9 8.2 93
33 12/18/17 w Building C 388 4 0 134.9 7.4 125.8 9.0 93
34 12/18/ 17 E Driveway F 378 4 0 134.9 7.4 122.7 9.6 91
35 12/19/17 w Building C 389 4 0 134.9 7.4 125.9 8.9 93
36 12/19/17 Mid Building C 387 4 0 134.9 7.4 124.7 8.5 92
37 12/19/17 E Building C 385 4 0 134.9 7.4 124.3 8.8 92
38 12/20/17 E Building C 385 4 0 134.9 7.4 120.6 4.3 89
38 A 12/21/17 E Building C 385 4 0 134.9 7.4 122.7 8.9 91
39 12/20/17 E Building C 384 4 0 134.9 7.4 120.3 4.1 89
39 A 12/21/17 E Building C 384 4 0 134.9 7.4 123.1 9.1 91
40 12/20/17 E Driveway F 380 4 0 134.9 7.4 119.8 4.4 89
40 A 12/21/17 E Driveway F 380 4 0 134.9 7.4 122.2 9.3 91
41 12/22/17 Driveway F 381 4 0 134.9 7.4 124.3 8.1 92
42 12/22/17 Mid Building C 387 4 0 134.9 7.4 124.0 7.9 92
43 12/22/17 w Building C 389 4 0 134.9 7.4 125.6 7.6 93
44 12/26/17 SE Building C 384 4 0 134.9 7.4 120.6 2.5 89
44 A 12/27/17 SE Building C 384 4 0 134.9 7.4 120.1 3.4 89
44 B 12/27/17 SE Building C 384 4 0 134.9 7.4 124.7 8.9 92
45 12/26/17 w Building B 386 4 0 134.9 7.4 118. l 2.4 88
45 A 01/04/18 w Building B 386 4 0 134.9 7.4 120.5 2.9 89
\ I I
0GEOCON
TABLE 1
SUMMARY OF FIELD DENSITY TEST RESULTS
Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-:
Elev. >¾" Max. Opt. Field Field Relative Test No. Date Curve Dry Moist Dry Moisture (MM/DD Location or Rock Compaction Depth No. Density Content Density Content /YY) (feet) (%) (pct) (%) (pct) (%) (%)
Pre. No. Re.
45 B 01/05/18 w Building B 386 4 0 134.9 7.4 125.8 8.9 93
46 12/26/17 SE Building C 380 4 0 134.9 7.4 120.3 4.5 89
46 A 12/26/17 SE Building C 380 4 0 134.9 7.4 123 .1 8.5 91
47 12/16/17 w Building C 384 4 0 134.9 7.4 125 .1 8.6 93
48 12/26/17 w Building C 383 4 0 134.9 7.4 125.5 8.7 93
49 12/26/17 E Driveway F 368 4 0 134.9 7.4 121 .3 8.5 90
50 12/28/17 SE Building C 381 4 0 134.9 7.4 122.9 8.8 91
51 12/28/17 s Building C 385 4 0 134.9 7.4 125.3 8.7 93
52 12/28/17 NW Building C 385 4 0 134.9 7.4 127.4 9.0 94
53 12/29/17 s Building C 386 4 0 134.9 7.4 125.6 8.6 93
54 12/29/17 NW Building C 386 4 0 134.9 7.4 119.6 2.6 89
54 A 12/29/17 NW Building C 386 4 0 134.9 7.4 121.9 8.5 90
55 12/29/17 SW Building C 390 4 0 134.9 7.4 123 .8 9.1 92
56 12/29/1 7 NE Building C 385 4 0 134.9 7.4 125.4 8.9 93
57 12/29/17 SE Building B 385 4 0 134.9 7.4 119.8 3.8 89
57 A 01 /02/18 SE Building B 385 4 0 134.9 7.4 120.6 2.9 89
57 B 01 /02/18 SE Building B 385 4 0 134.9 7.4 120.3 4.6 89
57 C 01 /03 /18 SE Building B 385 4 0 134.9 7.4 120.3 3.8 89
57 D 01 /03 /18 SE Building B 385 4 0 134.9 7.4 118.4 3.0 88
57 E 01 /04/18 SE Building B 385 4 0 134.9 7.4 124.2 8.5 92
58 12/29/17 SW Building B 383 4 0 134.9 7.4 I 16.7 2.0 87
58 A 01 /02/18 SW Building B 383 4 0 134.9 7.4 119.2 2.2 88
58 B 01/02/18 SW Building B 383 4 0 134.9 7.4 119.1 4.2 88
58 C 01 /03/18 SW Building B 383 4 0 134.9 7.4 119.7 4.3 89
58 D 01/03/18 SW Building B 383 4 0 134.9 7.4 120.6 2.5 89
58 E 01 /04/18 SW Building B 383 4 0 134.9 7.4 124.0 8.9 92
59 01/02/ l 8 w BuildingB 386 16 20 136.4 6.6 120.7 3.2 88
59 A 01/04/18 w Building B 386 16 20 136.4 6.6 126.4 8.0 93
60 01/02/18 E Building B 386 4 0 134.9 7.4 1 I 9.4 4.1 89
60 A 01/04/18 E Building B 386 4 0 134.9 7.4 122.6 9.1 91
I I
~GEOCON
TABLE 1
SUMMARY OF FIELD DENSITY TEST RESULTS
Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-:
Elev. >¾" Max. Opt. Field Field Relative Date Test No. or Curve Dry Moist Dry Moisture (MM/DD Location Depth No. Rock Density Content D~nsity Content Compaction
/YY) (feet) (%) (pct) (%) (pct) (%) (%)
Pre. No. Re.
61 01/03/18 w Driveway F 387 4 0 134.9 7.4 119.6 3.5 89
61 A 01/05/18 w Driveway F 387 4 0 134.9 7.4 123.7 9.1 92
62 01/03/18 E Driveway F 381 4 0 134.9 7.4 120.4 3.9 89
62 A 01/05/18 E Driveway F 381 4 0 134.9 7.4 122.2 8.5 91
63 01/04/18 NW Building B 387 4 0 134.9 7.4 120.1 2.6 89
63 A 01/05/18 NW Building B 387 4 0 134.9 7.4 124.5 9.0 92
FG 64 01/08/18 E Building C 386 4 0 134.9 7.4 124.8 8.8 93
FG 65 01/08/18 E Building C 387 4 0 134.9 7.4 125.4 9.2 93
FG 66 01/08/18 N Building C 388 4 0 134.9 7.4 126.1 9.0 93
FG 67 01/08/18 w Building C 389 4 0 134.9 7.4 122.7 8.8 91
FG 68 01/08/18 w Building C 391 4 0 134.9 7.4 123.9 9.3 92
69 01/16/18 w Driveway F 386 4 0 134.9 7.4 124.3 8.5 92
70 01/16/18 E Driveway F 383 4 0 134.9 7.4 125. l 8.8 93
71 01/16/18 N Building A 392 16 20 136.4 6.6 120.3 4.2 88
71 A 01/20/18 N Building A 392 16 20 136.4 6.6 126.0 8.2 92
72 01/16/18 s Building A 392 16 20 136.4 6.6 121.0 4.5 89
72 A 01/20/18 s Building A 392 16 20 136.4 6.6 126.5 7.8 93
+J R Oltl €it! 8 I:}five•,1,'ay I< ~ -1-6 +o ~ M -1--l--&d u &9
74 01/18/18 w Building B 388 4 0 134.9 7.4 122.8 9.0 91
FG 75 01/18/18 w BuildingB 390 4 0 134.9 7.4 126.3 8.8 94
FG 76 01/18/18 w Building B 389 4 0 134.9 7.4 125.8 9.2 93
FG 77 01 /18/18 E Building B 388 4 0 134.9 7.4 126.7 8.6 94
FG 78 01/18/18 E Building B 387 4 0 134.9 7.4 124.4 9.1 92
79 01/19/18 w Building A 391 16 10 133.5 7.4 122.5 8.8 92
80 01/19/18 E Building A 393 16 10 133 .5 7.4 126.1 8.6 94
81 01/19/18 Building A 394 16 10 133.5 7.4 123.7 9.0 93
82 01/20/18 E Edge of Site 375 4 0 134.9 7.4 126.1 9.1 93
83 01/20/18 s Building A 388 16 10 133 .5 7.4 125.3 8.6 94
84 01/23/18 E Building A 390 16 10 133 .5 7.4 122.9 8.8 92
85 01/23/18 w Building A 394 16 10 133.5 7.4 123.7 9.2 93
Proctor
Curve No.
4
12
Sample No.
EI-I
EI-2
TABLE II
SUMMARY OF LABORATORY MAXIMUM DRY DENSITY
AND OPTIMUM MOISTURE CONTENT TEST RESULTS
ASTM D 1557
Maximum
Source and Description Dry Density
(pct)
Dark reddish brown, Silty fine SAND 134.9
Brown Silty, fine to course SAND 132.5
TABLE Ill
SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS
ASTM D 4829
Moisture Content Dry Density
Before Test (%) After Test(%) (pct)
7.6 13.5 119.4
7.2 12.2 120.7
TABLE IV
Optimum
Moisture
Content(%)
7.4
9.8
Expansion
Index
0
0
SUMMARY OF LABORATORY WATER-SOLUBLE SULFATE TEST RESULTS
CALIFORNIA TEST NO. 417
Sample No. Water-Soluble Sulfate(%) Sulfate Exposure
El-I 0.003 Not Applicable
EI-2 0.002 Not Applicable
TABLE V
SUMMARY OF FINISH GRADE EXPANSION INDEX AND SULFATE
EXPOSURE TEST RESULTS, AND RECOMMENDED FOUNDATION CATEGORY
Building Sample at Expansion CBC Recommended Sulfate Expansion Foundation Number Finish Grade Index Classification Category Exposure
B EI-2 0 Very Low I Not Applicable
C EI-I 0 Very Low I Not Applicable
Project No. 06442-32-28A February 9, 2018