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HomeMy WebLinkAboutPD 2021-0014; RANCHO CARILLO HOA SLOPE REPAIR; GEOTECHNICAL INVESTIGATION; 2017-03-21SCSI, Inc. Corporate Headquarters 6280 Riverdale Street San Diego, CA 92120 1 877.215.4321 P 619.280.4321 r 619.280.4717 W www.scst.com SDVOSB . DVB GEOTECHNICAL INVESTIGATION RANCHO CARRILLO MASTER ASSOCIATION EROSION STUDY CARLSBAD, CALIFORNIA PREPARED FOR: MS. JENNIFER OJEDA, CMCA, CCAM COMMUNITY ASSOCIATION MANAGER WALTERS MANAGEMENT 327 GREY HAWK COURT, SUITE 140 CARLSBAD, CALIFORNIA 92010 PREPARED BY: RC EIVED APR 02 2021 LAND DEVELOPMENT ENGI NEERING SCST, INC. 6280 RIVERDALE STREET SAN DIEGO, CALIFORNIA 92120 Providing Professional Engineering Services Since 1959 Respectfully Submitted, SCST, INC. Emil RudoIpWPE, Principal Engineer Andrew K. NeuII Senior Geologist SCSI, Inc. Corporate Headquarters 6280 Piverdale Street San Diego, CA 92120 T 877.215.4321 P 619.280.4321 619.280.4717 W www.scst.com SDV0SB.DVB March 21, 2017 Ms. Jennifer Ojeda, CMCA, CCAM Community Association Manager Walters Management 327 Grey Hawk Court, Suite 140 Carlsbad, California 92010 SCST No. 160550N Report No. I Subject: GEOTECHNICAL INVESTIGATION RANCHO CARRILLO MASTER ASSOCIATION EROSION STUDY CARLSBAD, CALIFORNIA Dear Ms. Ojeda: SCSI, Inc. (SCSI) is pleased to submit our report describing the geotechnical investigation performed for the planned slope reconstruction at the open space area on the north side of El Fuerte Street in Carlsbad, California. This investigation was conducted as a response to slope erosion that occurred along the slope. If you have any questions with this report, or need additional information, please call us at (619) 280-4321. AKN:ER:CJM:rt:aw (1) Addressee via e-mail: JOjeda@WaltersManagement.com TABLE OF CONTENTS SECTION PAGE EXECUTIVESUMMARY............................................................................................................... IINTRODUCTION.....................................................................................................................2 2 SCOPE OF WORK.................................................................................................................2 2.1. FIELD INVESTIGATION.................................................................................................2 2.2. LABORATORY TESTING...............................................................................................2 2.3. ANALYSIS AND REPORT..............................................................................................2 3 SITE AND SUBSURFACE CONDITIONS...............................................................................3 3.1. SITE DESCRIPTION......................................................................................................3 3.2. SITE HISTORY...............................................................................................................3 3.3. SUBSURFACE CONDITIONS........................................................................................3 4 CONCLUSIONS AND RECOMMENDATIONS .......................................................................4 4.1. EXCAVATION CONDITIONS .........................................................................................4 4.2. TEMPORARY EXCAVATION SLOPES..........................................................................4 4.3. SITE PREPARATION AND GRADING...........................................................................4 4.4. FILL MATERIAL .............................................................................................................5 4.5. COMPACTED FILL ........................................................................................................5 5 CLOSURE ..............................................................................................................................6 5.1 GEOTECHNICAL REVIEW ............................................................................................6 5.2 LIMITATIONS.................................................................................................................6 ATTACHMENTS FIGURES Figure1.................................................................................................................Site Vicinity Map Figure 2...............................................................................................Subsurface Exploration Map Figure 3.......................................................................................................Geologic Cross Section Figure 4 ........................................................................................................Stabilization Fill Detail APPENDICES AppendixI..........................................................................................................Field Investigation AppendixII ........................................................................................................ Laboratory Testing EXECUTIVE SUMMARY This report presents the results of the geotechnical investigation SCST, Inc. (SCST) performed for the subject project. The site is located in an open space area on the north side of El Fuerte Street in the city of Carlsbad, California. We understand erosion occurred on a slope at the site. The erosion consists of gullies that have cut through the existing slope surface materials and have undermined an existing concrete-lined brow ditch. The purpose of our work isto provide conclusions and recommendations regarding the geotechnical aspects of the project. The subsurface conditions were explored by mapping and logging the materials exposed in the side walls of the gullies on the slope using field measurements and observations. Additionally, four exploratory borings were advanced using hand tools along the slope to depths of between about 41/2 to 6 feet below the existing ground surface. An SCST geologist logged the borings and collected samples of the subsurface materials encountered for laboratory testing. The materials encountered in the exploratory borings consist of fill and Quaternary-age colluvium. The fill consists of moist, loose to medium dense, poorly-graded gravel with clay and sand, moist, medium dense clayey sand with gravel, and medium stiff sandy lean clay. The colluvium consists of medium dense silty and clayey sand. Groundwater was not encountered in the borings. At the time of our site visit, wet conditions were present due to recent rain events. The main geotechnical conditions affecting the project are difficult excavation and backfill conditions due to the presence of steep slopes, eroded soil, and cobbles and debris in the fill. In order to reduce the potential for surficial erosion, we recommend vegetation and/or other man-made erosion control measures be constructed on the fill slope. Additionally, debris greater than 12 inches in dimension may need to be removed. Walters Management March 21, 2017 Rancho Carrillo Master Association Erosion Study SCST No. 160550N-1 Carlsbad, California Page 2 I INTRODUCTION This report presents the results of the geotechnical investigation SCST, Inc. (SCST) performed for the subject project. The site is located in an open space area on the north side of El Fuerte Street in the city of Carlsbad, California. We understand erosion occurred on a slope at the site from surface water flow over an existing brow ditch that was filled with soil and debris. The erosion consists of gullies that have cut through the existing slope surface materials and have undermined an existing concrete-lined brow ditch. The gullies extend from the brow ditch to the bottom of the slope. The purpose of our work is to provide conclusions and recommendations regarding the geotechnical aspects of the project. Figure 1 shows the site and surrounding vicinity. 2 SCOPE OF WORK 2.1. FIELD INVESTIGATION The subsurface conditions were explored by mapping and logging the materials exposed in the side walls of the gullies on the slope using field measurements and observations. Additionally, four exploratory borings were advanced using hand tools along the slope to depths of between about 41/2 to 6 feet below the existing ground surface. Borings B-2 and B-3 were excavated within existing gullies. The gully sidewalls were logged and included as part of the boring logs. Figure 2 shows the approximate location of the borings. An SCST geologist logged the borings and collected samples of the subsurface materials encountered for laboratory testing. The logs of the borings are presented in Appendix I. Soils are classified according to the Unified Soil Classification System illustrated on Figure I-I. 2.2. LABORATORY TESTING Selected samples obtained from the borings were tested to evaluate pertinent soil classification and engineering properties and enable development of geotechnical conclusions and recommendations. The laboratory tests consisted of grain size distribution and Atterberg limits. The results of the laboratory tests, and brief explanations of test procedures, are presented in Appendix H. 23. ANALYSIS AND REPORT The results of the field and laboratory tests were evaluated to develop conclusions and recommendations regarding: Subsurface conditions along the slope repair Excavation conditions and the potential for difficult excavation Groundwater levels and the necessity for dewatering Allowable temporary excavation side slopes and the necessity for shoring Suitability of excavated materials for use as fill Appropriate types of fill materials as well as placement and compaction procedures SL Walters Management March 21, 2017 Rancho Carrillo Master Association Erosion Study SCST No. 160550N-1 Carlsbad, California Page 3 3 SITE AND SUBSURFACE CONDITIONS 3.1. SITE DESCRIPTION The site is located in an open space area on the north side of El Fuerte Street, approximately 150 feet west of Chorlito Street. The slope is approximately 75 feet high and descends to the west at an inclination of about 2:1 (horizontal to vertical). The upper approximately 20 feet of the slope is within rear yard areas of lots in a residential subdivision. The top of the existing slope is located approximately 130 feet west of Chorlito Street. A concrete-lined brow ditch separates the open space area and the residential lots. Figure 3 presents a cross section. Erosion has occurred below the brow ditch, undermining the concrete. The gullies extend from the brow ditch to near the toe of the slope. A concrete-lined storm water culvert, approximately 10 feet wide and 3 feet deep extends from a concrete head wall at the bottom of the fill slope to the northwest for about 400 feet. A corrugated metal pipe (CMP) exits the headwall and drains into the culvert. The CMP was observed to have corrosion in its bottom allowing water to seep below the pipe and culvert. The site was grubbed prior to our site visit to expose the erosional features. The area supports native grasses, bushes, and trees. Site elevations range from approximately 360 feet above mean sea level along Chorlito Street and 280 feet at the bottom of the slope near the culvert. 3.2. SITE HISTORY SCST obtained aerial photos to review for the property. Based on a review of aerial photographs, it appears the site consisted of a northwest-southeast trending drainage prior to the residential development. Mass grading appears to have been performed between the years of about 1967 to 1981. Generally, grading consisted of filling the drainage with about 75 feet of fill to create building pads. The subject property includes a portion of the slope and drainage. 3.3. SUBSURFACE CONDITIONS The materials encountered in the exploratory borings consist of fill and Quaternary-age colluvium. The fill consists of moist, loose to medium dense, poorly-graded gravel with clay and sand, moist, medium dense clayey sand with gravel, and medium stiff sandy lean clay. The colluvium consists of medium dense silty and clayey sand. Groundwater was not encountered in the borings. However, groundwater levels may fluctuate in the future due to rainfall, irrigation, broken pipes, or changes in site drainage. At the time of our site visit, wet conditions were present due to recent rain events. Because groundwater rise or seepage is difficult to predict, such conditions are typically mitigated if and when they occur. Walters Management March 21, 2017 Rancho Carrillo Master Association Erosion Study SCST No. 160550N-1 Carlsbad, California Page 4 4 CONCLUSIONS AND RECOMMENDATIONS We understand erosion occurred in the form of gullies on the slope from surface water flow over an existing brow ditch that was filled with soil and debris. In order to reduce the potential for further erosion, we recommend the gullies be filled as presented herein and the brow ditch restored. The main geotechnical conditions affecting the project are difficult excavation and backfill conditions due to the presence of steep slopes, eroded soil, and cobbles and debris in the fill. In order to reduce the potential for surficial erosion of the proposed fill slope, we recommend vegetation and/or other man-made erosion control measures be constructed on the fill slope. Additionally, debris greater than 12 inches in dimension may need to be removed. 4.1. EXCAVATION CONDITIONS An SCSI representative observed medium dense fill and colluvium during our field exploration. However, dense formational materials mapped as Tertiary-age Santiago Formation and Mesozoic- age metamorphosed and unmetamorphosed volcanic and sedimentary rocks can be anticipated below the fill and colluvium. The contractor should anticipate hard digging conditions, especially in deeper materials and have equipment capable of excavating dense materials on difficult access slopes. 4.2. TEMPORARY EXCAVATION SLOPES Temporary slopes in fill and colluvium should not be steeper than 1:1 (horizontal:vertical). The contractor's Competent Person should inspect the faces of temporary slopes daily before personnel are allowed to enter the excavation area. 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. Temporary slopes steeper than those described above will require shoring. Soldier piles and lagging, internally braced shoring, or trench boxes could be used. Ground surface deformations immediately adjacent to the trench could be greater where trench boxes are used compared to other methods of shoring. 4.3. SITE PREPARATION AND GRADING Site preparation should begin with the removal of the vegetation and deleterious matter in areas to receive fill. The existing fill exposed along the bottoms of the gullies should be excavated to approximately 2 feet. An SCSI representative should observe the conditions exposed in the bottom of the excavations to determine if additional excavation is required. Where fill is to be placed within the erosional repair on surfaces inclined steeper than 5:1 (horizontal to vertical), benches should be excavated to provide a relatively level surface for fill placement. Benches should extend through loose soils to expose competent material. An SCST representative S[ Walters Management March 21, 2017 Rancho Carrillo Master Association Erosion Study SCST No. 160550N-1 Carlsbad, California Page 5 should observe the conditions exposed in the bottom of the excavations to determine if additional excavation is required. A keyway should be established at the base of the fill slopes for the erosional repair. The keyway should be at least equipment width at the bottom, extend at least 2 feet into competent material and be sloped back at an inclination of about 2%. The keyway may need to be wider to accommodate compaction equipment. Final keyway recommendations will depend on the observations in the field. 4.4. FILL MATERIAL In general, the on-site soil will be suitable for backfill material of the slope. Due to the lack of on- site material, import fill will be needed. Imported fill should meet the recommended parameters for Caltrans Embankment Fill as modified in the following tables and tested by SCST prior to transport to the site. Table I - Import Fill Recommendations Sieve Size ASTM D422 Percent Passing 4" 100 146" 75-100 75-100 No.4 20-100 No.40 0-60 No. 200 0-50 Property Specification Test Method Plasticity Index 20 max CAL 204 pH 5-9 CAL 643 Sand Equivalent 10-20 CAL 217 4.5. COMPACTED FILL Fill should be placed in 6- to 8-inch thick loose lifts; moisture conditioned to near optimum moisture content, and compacted to at least 90% relative compaction. The maximum dry density and SFc Walters Management March 21, 2017 Rancho Carrillo Master Association Erosion Study SCST No. 160550N-1 Carlsbad, California Page 6 optimum moisture content for the evaluation of relative compaction should be determined in accordance with ASTM D1557. The compacted fill slope should not be constructed at an inclination greater than 2:1 (horizontal:vertical) unless soil reinforcement is installed accordance with manufacture's specifications and analysis by SCST. Compaction of slopes should be performed by back-rolling with a sheep foot compactor at vertical intervals of 2 feet or less as the fill is being placed, and by track-walking the face of the slope when the fill is completed. As an alternative, the fill slopes can be overfilled by at least 2 feet and cut back to expose dense material at the design line and grade. 5 CLOSURE 5.1 GEOTECHNICAL REVIEW The earthwork plans shall be reviewed by the geotechnical engineer to evaluate conformance with the intent of the conclusions and recommendations contained in this report. If project conditions or final design vary from those described in this report, SCSI should be contacted regarding the applicability of, and the necessity for any revisions to, the conclusions and recommendations presented in this report. Removal of unsuitable soils, and placement and compaction of backfill, should be observed by the geotechnical engineer. Appropriate field tests should be performed to provide quality control and quality assurance for backfill. 5.2 LIMITATIONS This report is based on the project as described.and the information obtained from the sub-surface investigation at the approximate locations indicated on Figure 2. The findings are based on the results of the field, laboratory and office investigations, combined with interpolation and extrapolation of conditions between and beyond the sub-surface investigation locations and reflect interpretation of the limited direct evidence obtained. This report has been prepared for the use of Walters Management in design of the described project. It may not contain sufficient information for other users or other purposes. This report has been prepared in accordance with generally accepted geotechnical practice in San Diego County. No warranty, express or implied, is given or intended with respect to the information contained in this report. o - ,,/, , e 10 0/ 511 q/ / e ,.o0" to -. / \ 0 -. - e - - Carrillo - Oe Ranch Park - insettia scot — _- - - e V .0 -------------- r Sil "o - 0 's, 41 r a Parad,seGle' Alga Norte ,? 0 \ Community Geode Lot'0 deco COzador nch,, 2J IF Park -- Project Site t'cS0Pat'cO0 60 C Se4o' ( setU3' 'tt' 01,,S0 Op ~01 Ra chO Cones Kinglet Ro'ad e Court 510 0 St eet p tapsR, 0' 0ç,arA0C0Oe ' '"5, Cocao)0R Limonite CO,, t <'.5 Col,bfl Lane S000rro Lane 3, - %eos, Voa I "(- °Ok Unic0r,so Street La Costa ee -o - ,\ Country °°elStreet ,1011P0°° — Club Sil : -a, ) 10 pl- 00,5 0 / Plaza ç de,00t,,, Paseo Real D // I 1' AlgaRoad Arg0t'0 .1 ' Ore. P,,,,,P Si —- C -- — ------ 0 — 0' °óei,5,00' Terra1A5''0 ,2 0 bera .11 cit '<asp,, CO El 14 S (:2 SCST, Inc. SITE VICINITY MAP Rancho Carrillo Erosion Study El Fuerte St & Chorlito Carlsbad, California Date: March, 2017 By: MAW Job No.: 160550N-1 Figure: 1 im Concrete-lined 330 11 Bench 32 310 Headwall LHead 300 Qf 290- orrUgated QC01 Metal 27& Pipe 350 340 330 9- 320 0 Co 310 CD Qf Chorlito UA Street A' Brow 120 130 140 150 160 110 180 Horizontal Distance (feet) in SCST LEGEND: Approximate Location of Boring (Depth in Feet from Existing Slope Surface) Approximate Location of Geologic Contact, Queried Where Uncertain I1 Z u SCST, Inc. Qf Fill Qcol Colluvium CROSS SECTION Rancho Carrillo Erosion Study El Fuerte St & Chorlito St Carlsbad, California 0 40' 80' Scale Date: March, 2017 By: MAW Job No.: I 60550N-1 0 Figure: 3 3' TYPICAL BLANKET FILL IF RECOMMENDED BY THE GEOTECHNICAL ENGINEER TOP WIDTH OF FILL AS SPECIFIED BY THE GEOTECHNICAL ENGINEER COMPETENT MATERIAL ACCEPTABLE TO THE SOIL ENGINEER COMPACTED FILL . ......... FACE OF FINISHED SLOPE I L MINIMUM HEIGHT OF BENCHES IS 4' OR AS RECOMMENDED BY L MINIMUM TILT BACK GEOTECHNICAL ENGINEER OR 2% SLOPE (WHICHEVER IS GREATER) 0 10' 20' mmmm Scale STABILIZATION FILL DETAIL NEI" Date: March, 2017 Figure: de Rancho Carrillo Erosion Study El LU By: MAW SCST, Inc. Fuerte St & Chorlito St Carlsbad, California Job No.: 160550N-1 4 2' MINIMUM KEY DEPTH APPENDIX I APPENDIX I FIELD INVESTIGATION Our field investigation consisted of mapping and logging the materials exposed in the side walls of the gullies and excavating four exploratory borings with hand tools on February 13, 2017. Figure 2 shows the approximate boring locations. The field investigation was performed under the observation of an SCSI geologist who also logged the borings and obtained disturbed bulk samples of the materials encountered. The soils are classified in accordance with the Unified Soil Classification System as illustrated on Figure I-I. Logs of the test pits are presented on Figures 1-2 through 1-5. S, SUBSURFACE EXPLORATION LEGEND UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION GROUP SYMBOL TYPICAL NAMES COARSE GRAINED, more than 50% of material is larger than No. 200 sieve size. GRAVELS CLEAN GRAVELS More than half of GW Well graded gravels, gravel-sand mixtures, little or no fines 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 More than half of SW Well graded sand, gravelly sands, little or no fines. 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. FINE GRAINED, more than 50% of material is smaller than No. 200 sieve size. SILTS AND CLAYS ML Inorganic silts and very fine sands, rock flour, sandy gilt 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. SILTS 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. SAMPLE SYMBOLS LABORATORY TEST SYMBOLS - Bulk Sample AL - Atterberg Limits CAL - Modified California sampler CON - Consolidation CK - Undisturbed Chunk sample COR - Corrosivity Tests MS - Maximum Size of Particle (Resistivity, pH, Chloride, Sulfate) ST - Shelby Tube DS - Direct Shear SPT I - Standard Penetration Test sampler El - Expansion Index MAX - Maximum Density GROUNDWATER SYMBOLS RV - R-Value V - Water level at time of excavation or as indicated SA - Sieve Analysis UC - Unconfined Compression - Water seepage at time of excavation or as indicated Rancho Carrillo Master Association Erosion Study • Inc. Carlsbad, California By: CJM Date: March, 2017 II SCST, Job Number: 160550N-1 Figure: 1-1 * LOG OF EXPLORATORY BORING B-I Date Drilled: 2/13/2017 Logged by: CJM Equipment Hand Tools Project Manager: AKN Elevation (ft): Depth to Groundwater (ft):Not encountered - SAMPLES W • CO) I- w I vi z W 0 SUMMARY OF SUBSURFACE CONDITIONS E W- zo D 0 a - SC FILL (Of): CLAYEY SAND with GRAVEL, moderate yellowish brown, fine grained, moist, - - - - - - - medium dense, cobble up to 4-inches in diameter encountered, fragments of sandstone and concrete. -1 Moderate brown 11/2 X SA AL -2 - -2% - CL SANDY LEAN CLAY, mottled brown and yellowish brown, fine grained, moist, medium stiff. .31/2 SA - 41/2 - - - - - - - PRACTICAL REFUSAL AT 41/2 FEET COBBLES -5 .5% -6 -6% .7 -7% -8 -8% -9 -9% -10— I Rancho Carrillo Master Association Erosion Study 0 OIL I ac Carlsbad, California I SCST, Inc I H . By: CJM March, 2017 IJob Number: 160550N-1 1-2 I LOG OF EXPLORATORY BORING B-2 Date Drilled: 2/13/2017 Logged by: CJM Equipment: Hand Tools Project Manager: AKN Elevation (ft): Depth to Groundwater (ft):Not encountered - - SAMPLES W I— .S '— 0 — z W z I I— >- I UJ z ci,• 0 W (L D SUMMARY OF SUBSURFACE CONDITIONS O Z9 z 0 W GP- FILL FILL (Of): POORLY-GRADED GRAVEL with CLAY and SAND, moderate yellowish -2 GC brown, fine to coarse grained, moist, loose, cobble up to 6-inches in diameter SA encountered. AL Fine grained, more fines. 11/2 -2 Fine to coarse grained, loose to medium dense. -2% -3 -4 .41/2 Approximate bottom of gully -5 -- .51/2 PRACTICAL REFUSAL AT 6 FEET ON COBBLES -6% -7 .71/2 -8 -8% -9 .91/2 -10— Rancho Carrillo Master Association Erosion Study I cc Carlsbad, California I SCST, Inc. IBy: CJM March, 2017 I IJob Number: 160550N-1 1-3 - I LOG OF EXPLORATORY BORING B-3 Date Drilled: 2113/2017 Logged by: CJM Equipment: Hand Tools Project Manager: AKN Elevation (ft): Depth to Groundwater (ft): Not encountered - SAMPLES C. W I— z CI) I VJ 0 Z — _ W I— i Q Z W D 0 0 W 0 SUMMARY OF SUBSURFACE CONDITIONS > W .- zo Z D 0 U) >- - SC FILL (Of): CLAYEY SAND with GRAVEL, moderate yellowish brown, fine grained, moist, - - - - - - 1/2 loose, cobble up to 8-inches in diameter encountered. -1 - I /2 Moist to wet. -2 -2% 3 -- Approximate bottom of gully .3112 -4 -41/2 - - - - - - - PRACTICAL REFUSAL AT 41/2 FEET ON COBBLES -5 -5% -6 -6% -7 -7% -8 -8% -9 -9% -10— - - - - - - I Rancho Carrillo Master Association Erosion Study Carlsbad, California MHz I SCSI, Inc. By: CJM March, 2017 IJob Number: 160550N-1 1-4 LOG OF EXPLORATORY BORING B-4 Date Drilled: 2/13/2017 Logged by: CJM Equipment: Hand Tools Project Manager: AKN Elevation (ft): Depth to Groundwater (ft): Not encountered - - SAMPLES .B I— Lu - I— I U, w I— U) 0 co Z w 0 0 a.SUMMARY OF SUBSURFACE CONDITIONS w -. of z >IM 0 0 - CL FILL (Qfl: SANDY CLAY, reddish brown, fine grained, moist, medium stiff, cobble up to 4- - - - - - - /'2 inches encountered. - COLLUVIUM (Qcol): SILTY SAND, mottled light yellowish brown, fine grained, moist, medium dense, massive, oxidation. - 11/2 2 V SA 21/2 Moderate gray, moist to wet. 3 31/2 - — aaTn,un dense, massivigi I I BORING TERMINATED AT 5 6 6% 7 71/2 8 9 10 Rancho Camllo Master Association Erosion Study NEU. I cc Carlsbad, California I S CST, Inc. By: CJM March, 2017 I IJob Number: 160550N-1 1-5 APPENDIX II APPENDIX II LABORATORY TESTING Laboratory tests were performed to provide geotechnical parameters for engineering analyses. The following tests were performed: CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. GRAIN SIZE DISTRIBUTION: The grain size distribution was determined on four samples in accordance with ASTM D422. The test results are presented on Figures Il-I through 11-4. ATTERBERG LIMITS: The Atterberg limits were determined on two soil samples in accordance with ASTM D4318. The test results are presented on Figures Il-I and 11-3. Soil samples not tested are now stored in our laboratory for future reference and analysis, if needed. Unless notified to the contrary, all samples will be disposed of 30 days from the date of this report S ' SAMPLE LOCATION I B-i at I to 2 Feet I Inc. Rancho Carrillo Master Association Erosion Study Carlsbad, California By: CJM Date: March, 2017 Job Number: 160550N-1 Figure: Il-I U.S. Standard Stave Sizes 6" 3" 3/4" 3/8" #4 #8 #10 #16 #30 #40#50 #100 #200 100 90 70 M 60 if 50 1:: 20 10 0 ,. 1000 100 10 1 0.1 0.01 Grain Size in Millimeters Cobbles Gravel Sand Silt or Clay Coarse I Fine Coarse I Medium Fine I UNIFIED SOIL CLASSIFICATION: SC CLAYEY SAND with I I DESCRIPTION GRAVEL ATERBERG LIMITS ___________ LIQUID LIMIT 50 PLASTIC LIMIT 20 PLASTICITY INDEX 30 U.S. Standard Sieve Sizes 6" 3" 144" 3/4" 3/8" #4 #8#10 #16 #30 #40#50 #100 #200 100 -... 90 80 60 50 840 30 20 10 0 1000 100 10 1 0.1 0.01 Grain Size in Millimeters Cobbles Gravel I Sand Silt or Clay Coarse I Fine I Coarse I Medium I Fine SAMPLE LOCATION B-I at 3 to 41% Feet UNIFIED SOIL CLASSIFICATION: I CL DESCRIPTION I SANDY LEAN CLAY ATTERBERG LIMITS LIQUID LIMIT NIT PLASTIC LIMIT NIT PLASTICITY INDEX NIT S©.. Rancho Carrillo Master Study SCST, Inc. Carlsbad, California CJM I Date: Number: I60550N-1 lFigur h, 2017 11-2 I SAMPLE LOCATION B-2 at 0 to 1 Foot I 0 Ell II SCST, Inc. Rancho Carrillo Master Association Erosion Study Carlsbad, California By: CJM Date March 2017 Job Number: 160550N-1 1Figure: 11-3 U.S. Standard Sieve Sizes 6" 3" l-W 3/4' 3/8" #4 #8 #10 #16 #30 #40#50 #100 #200 100 90 80 R 70 60 8) j50 40 0 30 20 10 0 1000 100 10 1 0.1 0.01 Grain Size in Millimeters Cobbles Gravel Sand Silt or Clay Coarse I Fine Coarse I Medium I Fine UNIFIED SOIL CLASSIFICATION: GP-GC POORLY GRADED DESCRIPTION GRAVEL with CLAY and SAND ATERBERG LIMITS LIQUID LIMIT 34 PLASTIC LIMIT 24 PLASTICITY INDEX 10 U.S. Standard Steve Sizes 6. 3 1-W 314 3/8 #4 #8 #10 #16 #30 #40#50 #100 #200 100 90 80 R 70 60 50 it- 40 IL 30 20 10 1000 100 10 1 0.1 0.01 Grain Size in Millimeters Cobbles Gravel I Sand Silt or Clay Coarse I Fine I Coarse I Medium I Fine SAMPLE LOCATION UNIFIED SOIL CLASSIFICATION: I SM B-4 at Ito 3% Feet I DESCRIPTION I SILTY SAND ATTERBERG LIMITS LIQUID LIMIT NIT PLASTIC LIMIT N/T PLASTICITY INDEX NIT Rancho Carrillo Master Association Erosion Study I Carlsbad, California I SCST, Inc. lJob By: CJM Date: March, 2017 Number: 160550N-1 Figure: 11-4 I