Appendix B: Geotechnical Report

Transcription

1 Appendix B: Geotechnical Report

2 August 24, 2016 Mr. Brad Perozzi Branch West 5000 Birch Suite 600 East Tower Newport Beach, California Subject: Geotechnical Due-Diligence Investigation, Proposed Multi-Family Residential Development, 1725 W. Katella Avenue, City of Orange, California. Dear Mr. Perozzi Albus-Keefe & Associates, Inc. is pleased to present to you our geotechnical due-diligence report for the proposed residential development at the subject site. This report presents the results of our historical aerial photographs and literature review, subsurface exploration, laboratory testing, and engineering analyses. Conclusions relevant to the feasibility of the proposed site development are also presented herein based on the findings of our work. We appreciate this opportunity to be of service to you. If you have any questions regarding the contents of this report, please do not hesitate to call. Sincerely, Patrick M. Keefe Principal Engineering Geologist

3 Branch West August 24, 2016 Page i TABLE OF CONTENTS REPORT 1.0 INTRODUCTION PURPOSE AND SCOPE SITE LOCATION AND DESCRIPTION PROPOSED DEVELOPMENT INVESTIGATION RESEARCH SUBSURFACE EXPLORATION LABORATORY TESTING SUBSURFACE CONDITIONS SOIL CONDITIONS GROUNDWATER FAULTING ANALYSES SEISMICITY STATIC SETTLEMENT Liquefaction CONCLUSIONS FEASIBILITY OF PROPOSED DEVELOPMENT GEOLOGIC HAZARDS Ground Rupture Ground Shaking Landsliding GROUNDWATER LIQUEFACTION STATIC SETTLEMENT EARTHWORK AND MATERIAL CHARACTERISTICS SOIL EXPANSION FOUNDATIONS CONCRETE MIX DESIGN PERCOLATION CHARACTERISTICS LIMITATIONS REFERENCES Figure 1 - Site Location Map Plate 1 Geotechnical Map FIGURES AND PLATES

4 Branch West August 24, 2016 Page ii TABLE OF CONTENTS REPORT APPENDIX A - Exploratory Logs Boring Logs - Plates A-1 through A-9 APPENDICES APPENDIX B - Laboratory Test Program Table B - Summary of Laboratory Test Results Plate B-1 Grain-Size Distribution Plot Plates B-2 and B-3 Direct Shear Plots

5 Branch West August 24, 2016 Page INTRODUCTION 1.1 PURPOSE AND SCOPE The purpose of our work was to evaluate the feasibility of proposed site development in order to assist you in your land acquisition evaluation and due-diligence review. The scope of our work for this investigation was focused primarily on the geotechnical issues that we expect to have significant fiscal impacts on future site development. While this report is comprehensive for the intended purpose, it is not intended for final design purposes. As such, additional geotechnical studies may be warranted based on our review of future rough grading plans and foundation plans. The scope of our geotechnical due-diligence work included the following: Review of available historical aerial photographs for the site and surrounding area Review of published geologic and seismic data for the site and surrounding area Exploratory drilling and soil sampling Laboratory testing of selected soil samples Engineering analyses of data obtained from exploration and laboratory testing Evaluation of site seismicity, liquefaction potential, settlement potential Preparation of this report 1.2 SITE LOCATION AND DESCRIPTION The site is located at 1725 W. Katella Avenue within the city of Orange, California. The property is bordered by the parking lot for Stadium Promenade Shopping Center to the north, an office building and an associated parking lot to the west, W. Katella Avenue to the south, and by a landscape area and water pumping station to the east. The location of the site and its relationship to the surrounding areas is shown on Figure 1, Site Location Map. The site comprises approximately one acre of land and is currently occupied by a two-story, commercial/office building. Improvements associated with the commercial/office building include asphalt paved parking areas to the north and south of the building, an asphalt paved drive isle along the west property line, minor concrete flatwork around the building, and scattered landscape islands. The northeast property line is bounded by chain-link fencing while the north and west property lines are bounded by masonry block walls retaining as much as 7 feet. Topographically the site is relatively flat with elevations ranging from approximately 172 feet above Mean Seal Level (MSL) in the northeast portion of the site to approximate 166 feet above MSL in the southwest portion of the site (based on Google Earth). The subject site is elevated in relation to the neighboring properties to the north and west. Drainage is generally directed to the south and southwest onto W. Katella Avenue via concrete gutters.

6 Branch West August 24, 2016 Page 2 SITE N SITE LOCATION MAP Branch West Proposed Residential Development 1725 W. Katella Avenue Orange, California NOT TO SCALE 2016 Google FIGURE 1

7 Branch West August 24, 2016 Page 3 Vegetation at the site consists of some grassy areas with minor shrubs and small to medium sizedtrees in the southern portion of the site adjacent W. Katella Avenue. Minor shrubs and small trees are also present within a few scattered landscape islands. 1.3 PROPOSED DEVELOPMENT We understand the proposed site development will consist of a new 5-story multi-family residential complex with one level of subterranean parking located beneath the residential units. Associated interior driveways, decorative hardscape, on-grade parking areas, subterranean parking improvements and underground utilities are also anticipated. No grading or structural plans were available in preparing of this proposal. However, we anticipate the structure will utilize up to 5 levels of wood framing over a concrete podium deck. The subterranean portion may consist of poured-in-place concrete walls, shotcrete walls, or CMU walls and column supports spaced about 30 feet on center. We anticipate minor rough grading of the site will be required to achieve future surface configurations beyond the limits of proposed subterranean improvements. Subterranean parking improvements will involve deeper excavations that will likely result in export operations of excess soils. Subterranean parking elements of the project will likely require shoring improvements during construction that are either temporary or incorporated as part of the permanent wall system. 2.1 RESEARCH 2.0 INVESTIGATION We have reviewed the referenced geologic publications, maps and aerial photographs (see references). Data from these sources were utilized to develop some of the findings and conclusions presented herein. Our research and review of available historical aerial photographs indicates that the site and the adjacent properties to the north and west were part of a historical aggregate mining operation that took place along the southeast bank of the Santa Ana River drainage course. Associated mining excavations appear to have been primarily located within the northern and western portions of the property. The mining operations were terminated sometime between 1967 and 1970 and the resulting excavations were backfilled with undocumented fill materials. By 1973, the perimeter retaining walls were constructed and by 1978, the existing building and asphalt paved parking lot were constructed. The site appears to have remained relatively unchanged since its development in SUBSURFACE EXPLORATION Subsurface exploration for this investigation was conducted on July 23, Our exploration consisted of drilling three (3) exploratory borings to depths of 36.5 to 51.5 feet below the existing ground surface utilizing a truck-mounted, hollow-stem-auger drill rig. Representatives of Albus- Keefe & Associates, Inc. logged the exploratory excavation. Visual and tactile identifications were made of the materials encountered, and their descriptions are presented in the Exploration Logs in

8 Branch West August 24, 2016 Page 4 Appendix A. The approximate locations of the exploratory excavations completed by this firm are shown on the enclosed Geotechnical Map, Plate 1. Bulk, standard penetration test (SPT) and relatively undisturbed samples were obtained at selected depths within the exploratory boring for subsequent laboratory testing. Relatively undisturbed samples were obtained using a 3-inch O.D., 2.5-inch I.D., California split-spoon soil sampler lined with brass rings. SPT samples were obtained using a standard SPT soil sampler. During each sampling interval, the sampler was driven 12 to 18 inches with successive drops of a 140-pound automatic hammer free falling approximately 30 inches. The number of blows required to advance the split-spoon and SPT samplers were recorded for each six inches of advancement. The total blow count for the lower 12 inches of advancement per sample is recorded on the boring logs. Samples were placed in sealed containers or plastic bags and transported to our laboratory for analyses. The borings were backfilled with auger cuttings and capped with AC cold patch upon completion of sampling. Two additional borings were drilled adjacent borings B-1 and B-2 for percolation testing. 2.3 LABORATORY TESTING Selected samples of representative earth materials from the borings excavated at the site were tested in the laboratory. Tests consisted of in-situ moisture content and dry density, maximum dry density and optimum moisture content, expansion index, soluble sulfate content, direct shear strength, grainsize analysis, minus #200 wash, Atterberg limits, and corrosion series. Descriptions of laboratory test criteria and a summary of the test results are presented in Appendix B and on the boring logs in Appendix A. 3.1 SOIL CONDITIONS 3.0 SUBSURFACE CONDITIONS Descriptions of the earth materials encountered during our investigation are summarized below and are presented in detail on the Exploration Logs presented in Appendix A. Soil materials encountered at the site consist of alluvial deposits overlain by undocumented artificial fills associated with the previous mining operations. Based on our exploratory borings, the artificial fill materials typically measure 5 to 8 feet below existing grades. However, artificial fills of greater thickness may be present within portions of the site due to the past mining activities and underground utilities. The artificial fill materials are generally comprised of dark brown and very dark gray clayey sand and silty sand with some gravel and miscellaneous debris. These materials are typically damp to moist and loose to medium dense. The alluvial deposits were encountered below the artificial fill materials to the maximum depth of exploration, 51.5 feet below the ground surface (bgs). The alluvial deposits are comprised of predominantly coarse-grained soils with occasional fine-grained layers. The coarse-grained soils typically consist of sand, sand with silt, silty sand, and silty sand with gravel. These deposits are typically damp to very moist and loose to medium dense but become dense to very dense at a depth of about 35 feet beneath the ground surface.

9 Branch West August 24, 2016 Page 5 The fine grained deposits typically consist of various shades of brown sandy clay, sandy silty clay, sandy clay with gravel, clay with sand, and clay with gravel. These deposits are typically moist, medium stiff to hard, and are up to 4 feet in thickness. 3.2 GROUNDWATER Groundwater was not encountered during this firm s subsurface exploration to the maximum depth explored, 51.5 feet below the existing ground surface. A review of the CDMG Seismic Hazard Zone Report 011 indicates that historical high groundwater levels for the general site area have been reported as shallow as 15 to 20 feet below the existing ground surface. However review of well records in the vicinity of the site going back to 1932 indicates that the shallowest groundwater level in the general area was at a depth of 57.9 feet below ground surface (measured in May 2006). 3.3 FAULTING Based on our review of the referenced publications and seismic data, no faults are known to project through or immediately adjacent the site and the site does not lie within an "Earthquake Fault Zone" as defined by the State of California in the Alquist-Priolo Earthquake Fault Zoning Act. Table 3.1 presents a summary of all the known active faults within 10 miles of the site, based on the 2008 U.S.G.S. National Seismic Hazard Maps. TABLE 3.1 Summary of Faults Name Distance (miles) Slip Rate (mm/yr.) Preferred Dip (degrees) Slip Sense Rupture Top (km) Fault Length (km) Puente Hills (Coyote Hills) thrust San Joaquin Hills thrust Elsinore;W+GI+J 8.17 n/a 84 strike slip Elsinore;W+GI+T+J 8.17 n/a 84 strike slip Elsinore;W+GI+T+J+CM 8.17 n/a 84 strike slip Elsinore;W+GI 8.17 n/a 81 strike slip 0 83 Elsinore;W strike slip 0 46

10 Branch West August 24, 2016 Page ANALYSES 4.1 SEISMICITY We have performed probabilistic seismic analyses utilizing the U.S. Seismic Design Maps web application by the U.S. Geological Survey (USGS). From our analyses, we obtain a PGA of 0.50g in accordance with Figure 22-7 of ASCE The F PGA factor for site class D is 1.0. Therefore, the PGA M = 1.0 x 0.50g = 0.50g. The mean event associated with a probability of exceedance equal to 2% over 50 years has a moment magnitude of 6.53 and the mean distance to the seismic source is 10.1 miles. 4.2 STATIC SETTLEMENT Engineering analyses were performed to evaluate the settlement potential of footings. Structural loads are not know at this time but we have assumed the maximum column load will generally be 500 kips. Footings were assumed to be founded at a depth of 2 feet below finish floor and a bearing pressure of 3,500 psf was assumed. Three analyses were performed to evaluate differing finish floor elevations corresponding to depths of 5, 7, and 10 feet below current grade. Based on these assumptions, our estimated total settlements are summarized in Table 4.1 below. Finished Floor Depth (ft) Liquefaction Embedment of Footing below FF (ft) TABLE 4.1 Estimated Settlement of Footings Thickness of Eng. Fill below Footing (ft) Bearing Pressure (psf) Total Settlement (in) Modulus of Subgrade Reaction (pci) In consideration of the indication of historical shallow groundwater indicated by the CDMG, we performed liquefaction analysis to evaluate the potential effects if such conditions were to exist during a strong ground motion event. A groundwater depth of 18 feet was used for this analysis. Our analyses followed the guidelines presented in the CGS Special Publication 117A (2008), as modified in the procedures by Youd, et al. (2001). These analyses are based on field test data and laboratory test results from this investigation, PGA M =0.50g (discussed in Section 4.1). Based on the material description and blow count in the two borings (B-1 and B-2) that reached depth 51.5 feet, boring B-1 shows greater potential for liquefaction. As result, liquefaction analysis was done using the subsurface profile of this boring. Blow counts obtained from the larger California

11 Branch West August 24, 2016 Page 7 ring-lined sampler were corrected in the analyses (SCEC, 1999). Fine-grained soils that do not have a Plasticity Index (PI) less than 12 and field moisture contents greater than 85% of liquid limit (LL) or soils with corrected blow counts greater than 30 blows per foot were assumed to be not susceptible to liquefaction. Based on our analyses, a sand layer between the depths of approximately 18 and 26 feet has factors of safety below 1.3 and as such, is prone to liquefaction during a strong ground motion event if these materials are located below groundwater. Analyses were performed to evaluate the potential magnitude of settlement resulting from liquefaction of the layers with a liquefaction safety factor less than 1.3. The estimated settlement caused by saturated soil liquefaction was evaluated for the site based on the empirical procedures developed by Ishihara and Yoshimine (1992) and Tokimatsu and Seed (1987) which compare the volumetric strain in the soil with the induced cyclic stress ratios/liquefaction safety factors. Taking the average of these two methods, we estimate liquefaction settlement in the order of 2.5 inches. Differential seismic settlement is anticipated to be limited to 1/2 of the total or 1.3 inches. 5.0 CONCLUSIONS 5.1 FEASIBILITY OF PROPOSED DEVELOPMENT From a geotechnical point of view, the proposed site development is considered feasible provided the recommendations presented in this report are incorporated into the design and construction of the project. Furthermore, it is also our opinion that the proposed development will not adversely impact the stability of adjoining properties. Key issues that could have significant fiscal impacts on the geotechnical aspects of the proposed site development are discussed in the following sections of this report. 5.2 GEOLOGIC HAZARDS Ground Rupture No active faults are known to project through the site nor does the site lie within the boundaries of an "Earthquake Fault Zone" as defined by the State of California in the Alquist-Priolo Earthquake Fault Zoning Act. The closest known active fault is the Puente Hills (Coyote Hills) Fault located approximately 5.31 miles from the site. As such, the potential for ground rupture due to a fault displacement beneath the sites is considered very low Ground Shaking The site is situated in a seismically active area that has historically been affected by generally moderate to occasionally high levels of ground motion. The site lies in relative close proximity to several active faults; therefore, during the life of the proposed improvements, the property will probably experience similar moderate to occasionally high ground shaking from these fault zones, as well as some background shaking from other seismically active areas of the Southern California region. Design and construction in accordance with the current California Building Code (CBC) requirements is anticipated to address the issues related to potential ground shaking.

12 Branch West August 24, 2016 Page Landsliding The site is not located within an area identified by the California Geologic Survey (CGS) as having potential for seismic slope instability. Geologic hazards associated with landsliding are not anticipated at the sites. 5.3 GROUNDWATER Groundwater was not encountered in our borings to a depth of approximately 52 feet. Nearby well data suggests that groundwater is present at a depth of approximately 90 to 120 feet. Well data extending back to 1932 suggests that groundwater generally rose about 50 feet until about Thereafter, groundwater has remained relatively constant, rising and falling about 25 feet over periods of several years. The suggestion that historical groundwater has been as shallow as 15 to 20 as indicated by the CDMG hazard report 011does not appear to be founded upon actual groundwater data. Groundwater contouring in the hazard map appears to be based on assumptions of a losing stream effect during periods of heavy flow in the Santa Ana River. Groundwater data we obtained was often obtained every month and there is no evidence in the data that such shallow groundwater conditions existed even for short durations during the rainy season. We therefore conclude that groundwater has existed and will remain below a depth of at least 50 feet during the next 50 years. 5.4 LIQUEFACTION Engineering research of soil liquefaction potential (Youd, et al., 2001) indicates that generally three basic factors must exist concurrently in order for liquefaction to occur. These factors include: A source of ground shaking, such as an earthquake, capable of generating soil mass distortions. A relatively loose silty and/or sandy soil. A relative shallow groundwater table (within approximately 50 feet below ground surface) or completely saturated soil conditions that will allow positive pore pressure generation. As discussed in Section 5.3, groundwater is not anticipated to occur within 50 feet of the ground surface during the design life of the project. Even if groundwater were to rise to a depth as shallow as 18 feet and a strong ground motion event occurred, we have estimated that seismic settlement would be on the order of 2 ½ inches with a differential settlement of about 1 ¼ inches. Based on the State of California Special Publication 117A, hazards from liquefaction should be mitigated to the extent required to reduce seismic risk to acceptable levels. The acceptable level of risk means, that level that provides reasonable protection of the public safety [California Code of Regulations Title 14, Section 3721 (a)]. The estimated magnitude of seismic settlement associated with groundwater rising to a depth of 18 feet would generally not require any significant mitigation to achieve this requirement.

13 Branch West August 24, 2016 Page STATIC SETTLEMENT Soils underlying the site are moderately compressible and could cause excessive settlement under the weight of significant foundation loads. Based on our analyses, total and differential settlement can be reduced by the removal and replacement of native soils underlying the footings. The depth of removal will depend upon both the foundation load and the elevation of the finish floor. Provided the finish floor of the subterranean level is about 5 to 10 feet below current grade, removal and recompaction of existing soils to a depth of about 15 feet below current grade is anticipated to provide sufficient reduction of settlement. With this thickness of fill, we anticipate that footings supporting up to about 500 kips will have maximum total and differential settlements of 1 ½ inches and 1/2 inch over 30 feet, respectively. These values are considered within tolerable limits of proposed structures and site improvements. 5.6 EARTHWORK AND MATERIAL CHARACTERISTICS The site is underlain with 5 to 8 feet of undocumented fill that is considered unsuitable for support of proposed development. These materials will require removal and recompaction within the areas of site development. In addition, existing soils will require over-excavation and recompaction to depths of 2 to 7 feet below the bottom of footings (up to 15 feet below current grade) to reduce settlement to tolerable limits, depending upon the depth to the finish floor and the actual column loads. Existing surficial soils are anticipated to be relatively easy to excavate with conventional heavy earthmoving equipment. Removal and recompaction of the site materials will result in some minor to moderate shrinkage and subsidence. Design of site grading will require consideration of this loss when evaluating earthwork balance issues. Site materials are generally slightly below optimum to slightly above optimum moisture. As such, the soils will generally require the addition of minor amounts of water in preparation for reuse as compacted fill. Site materials are friable and may be prone to sloughing and possible caving if allowed to dry. Temporary construction slopes and trench excavations can likely be cut vertically up to a height of 3 feet within the onsite materials provided that no surcharging of the excavations is present. Temporary excavations greater than 3 feet in height will generally require a layback to 1:1.5 (H:V) or require shoring. Since sections of the subterranean level are very near the property lines, shoring of these areas should be anticipated. Since existing soils are anticipated to require over-excavation below planned grades, shoring could be required to retain up to 15 feet to accommodate both planned cuts and over-excavation. Portions of the site soils are relatively cohesionless and may be prone to caving in uncased drill shafts. As such, casing may be required during drilling for soldier piles used in shoring. The site is currently occupied by structures as well as asphaltic and concrete paving. Asphaltic concrete and concrete debris generated by demolition can be reduced to no more than 4 inches in maximum dimension and uniformly incorporated within fill soils during earthwork operations.

14 Branch West August 24, 2016 Page SOIL EXPANSION Based on the USCS visual manual classification and laboratory test results, the near-surface soils within the site are generally anticipated to possess a Very Low to Low expansion potential. The presence of expansive soils can be readily mitigated through the use of nominal steel reinforcing in exterior flatwork and interior slabs on grade. Additional testing for soil expansion will be required subsequent to rough grading and prior to construction of foundations and other concrete flatwork to confirm these conditions. 5.8 FOUNDATIONS Based on our analyses of settlement potential, risks associated with liquefaction, and soil expansion characteristics, we anticipate the proposed structure can be supported by conventional spread footings and concrete slab on grade. Footings and slabs on grade will require minor reinforcing in consideration of expansive soils. 5.9 CONCRETE MIX DESIGN Laboratory testing of existing near-surface soils indicates negligible soluble sulfate content. No special requirements for concrete to resist sulfates are anticipated. Additional testing for soluble sulfate content will be required subsequent to rough grading and prior to construction of foundations and other concrete work to confirm these conditions PERCOLATION CHARACTERISTICS Percolation testing performed during our investigation indicates the site contains soils that have moderate infiltration rates that vary from about 3 to 5 inches/hour (measured rates). Due to the proposed subterranean level, infiltration of storm water will likely require the use of dry wells to insure the water is infiltrated below the level of the subterranean level. However, fine-grained soil layers are present at depth that will retard the flow of water from dry wells. Preliminary estimates indicate that a dry well will require about 85 hours to empty if the bottom level is 10 feet below current grade. If the bottom level of the building is set at a shallower depth, the dry well can be designed to empty in less time. Generally the regional water quality control board requires BMPs to empty in 72 hours or less. As such, the use of dry wells may require the granting of an exception by the city if the final design does not demonstrate compliance with this requirement. If dry wells are not accepted for the project, then other methods of treatment will be required such as bio-filtration. 6.0 LIMITATIONS This report is based on the proposed development and geotechnical data as described herein. The materials described herein and in other literature are believed representative of the total project area, and the conclusions contained in this report are presented on that basis. However, soil materials can vary in characteristics between points of exploration, both laterally and vertically, and those variations could affect the conclusions and recommendations contained herein. As such, observation

15 Branch West August 24, 2016 Page 11 and testing by a geotechnical consultant prior to and during the grading and construction phases of the project are essential to confirming the basis of this report. This report summarizes several geotechnical topics that should be beneficial for project planning and budgetary evaluations. The information presented herein is intended only for a preliminary feasibility evaluation and is not intended to satisfy the requirements of a site specific and detailed geotechnical investigation required for further planning, design and permitting. This report has been prepared consistent with that level of care being provided by other professionals providing similar services at the same locale and time period. The contents of this report are professional opinions and as such, are not to be considered a guaranty or warranty. This report should be reviewed and updated after a period of one year or if the site ownership or project concept changes from that described herein. This report has been prepared for the exclusive use of Branch West to assist the project consultants in determining the feasibility of the proposed development. This report has not been prepared for use by parties or projects other than those named or described herein. This report may not contain sufficient information for other parties or other purposes. Respectfully submitted, ALBUS-KEEFE & ASSOCIATES, INC Bidjan Ghahreman David E. Albus Associate Engineer Principal Engineer PhD, PE C80886 GE 2455

16 Branch West August 24, 2016 Page 12 Publications REFERENCES California Department of Conservation, Division of Mines and Geology, Seismic Hazard Report 011, Seismic Hazard Zone Report for the Orange 7.5-Minute Quadrangles, Orange County, California, California Department of Conservation, Division of Mines and Geology, Special Publication 117A Guidelines for Evaluating and Mitigating Seismic Hazards in California, Seed, H.B., Idriss, I.M., Ground Motions and Soil Liquefaction During Earthquakes, published by the EERI, dated December Seed, R.B., Cetin, K.O., Moss, R.E.S., Kammerer, A.M., Wu, J., Pestana, J.M., Riemer, M.F., Sancio, R.B., Bray, J.D., Kayen, R.E., and Faris, A., Recent Advances in Soil Liquefaction Engineering: A Unified and Consistent Framework, 26 th Annual ASCE Los Angeles Geotechnical Spring Seminar, Long Beach, California, April 30, Southern California Earthquake Center (SCEC), University of Southern California, Recommended Procedures for Implementation of DMG Special Publication 117 Guidelines for Analyzing and Mitigating Liquefaction Hazards in California, March, Tokimatsu, K. & Seed, H.B., Evaluation of Settlement in Sands Due to Earthquake Shaking, Journel of Geotechnical Engineering, Vol. 113, No. 8, August, 1987 Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J., Dobry, R., Finn, W.D.L., Harder, L.F., Hynes, M.E., Ishihara, K., Koester, J.P., Liao, S.S.C., Marcuson, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K., Seed, R.B., and Stokoe, K.H., Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils, Journal of Geotechnical and Geoenvironmental Engineering, October, Aerial Photographs Photo Source Date Flown Flight No. Continental Aerial Photo, Inc F222 Continental Aerial Photo, Inc Continental Aerial Photo, Inc Continental Aerial Photo, Inc Continental Aerial Photo, Inc Continental Aerial Photo, Inc Continental Aerial Photo, Inc AXK-6K-19

17 PROJECT LIMIT P-2 B-2 B W Katella Ave, Orange WEST KATELLA AVENUE P-1 B APPROX SCALE : 1" = 60' B-3 EXPLANATION (Locations Approximate) - Exploratory Boring P-2 - Exploratory Percolation Well WEST STRUCK AVENUE GEOTECHNICAL CONSULTANTS 2016 Google GEOTECHNICAL MAP Job No.: Date: 08/24/16 Plate: 1

18 APPENDIX A EXPLORATION LOGS

19 E X P L O R A T I O N L O G Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab Tests EXPLANATION Solid lines separate geologic units and/or material types. 5 Dashed lines indicate unknown depth of geologic unit change or material type change. Solid black rectangle in Core column represents California Split Spoon sampler (2.5in ID, 3in OD). Double triangle in core column represents SPT sampler. 10 Solid black rectangle in Bulk column respresents large bag sample Other Laboratory Tests: Max = Maximum Dry Density/Optimum Moisture Content EI = Expansion Index SO4 = Soluble Sulfate Content DSR = Direct Shear, Remolded DS = Direct Shear, Undisturbed SA = Sieve Analysis (1" through #200 sieve) Hydro = Particle Size Analysis (SA with Hydrometer) 200 = Percent Passing #200 Sieve Consol = Consolidation SE = Sand Equivalent Rval = R-Value ATT = Atterberg Limits Albus-Keefe & Associates, Inc. Plate A-1

20 E X P L O R A T I O N L O G Project: 1725 W. Katella Avenue, Orange Location: B-1 Address: 1735 W Katella Ave, Orange, CA Elevation: Job Number: Client: Branch West Date: 7/23/2016 Drill Method: Hollow-Stem Auger Driving Weight: 140 lbs / 30 in Logged By: AJA Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab Tests Asphalt Concrete (AC): 2 inches Crushed Aggregate Base (CAB): 3 inches ARTIFICIAL FILL (Af) Clayey Sand (SC): Very dark gray, moist, loose, fine to medium sand, trace fine gravel ft., medium dense, few concrete fragments ALLUVIUM (Qal) Sand (SP): Pale brown, Moist, loose, fine to medium sand, trace fine gravel, micaceious ft., very loose, increased fine gravel DS 15 ft., medium dense, no gravel SA Albus-Keefe & Associates, Inc. Plate A-2

21 E X P L O R A T I O N L O G Project: 1725 W. Katella Avenue, Orange Location: B-1 Address: 1735 W Katella Ave, Orange, CA Elevation: Job Number: Client: Branch West Date: 7/23/2016 Drill Method: Hollow-Stem Auger Driving Weight: 140 lbs / 30 in Logged By: AJA Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab Tests 8 Sandy Clay (CL): Olive brown, moist, stiff, fine sand 23 Dist. ATT 30 ft., Dark brownmedium stiff, fine to medium sand, 31 ft., Reddish brown, damp, increased fines ft., hard Dist. ATT Silty Sand with Gravel (SM): Reddish brown, damp, dense, fine to coarse gravel, medium to coarse sand ft., very dense ft., decreased gravel 70 Sandy Silty Clay (CL-ML): Reddish brown, moist, hard, fine sand, micaceous Albus-Keefe & Associates, Inc. Plate A-3

22 E X P L O R A T I O N L O G Project: 1725 W. Katella Avenue, Orange Location: B-1 Address: 1735 W Katella Ave, Orange, CA Elevation: Job Number: Client: Branch West Date: 7/23/2016 Drill Method: Hollow-Stem Auger Driving Weight: 140 lbs / 30 in Logged By: AJA Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab 50 ft., stiff Dist. ATT Boring ended at 51.5 feet. No groundwater encountered. Backfilled with cuttings. Patched with cold patch AC. Additional Boring Drilled adjacent and converted into 15-foot test well. Albus-Keefe & Associates, Inc. Plate A-4

23 E X P L O R A T I O N L O G Project: 1725 W. Katella Avenue, Orange Location: B-2 Address: 1735 W Katella Ave, Orange, CA Elevation: Job Number: Client: Branch West Date: 7/23/2016 Drill Method: Hollow-Stem Auger Driving Weight: 140 lbs / 30 in Logged By: AJA Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab Tests Asphalt Concrete (AC): 3 inches Crushed Aggregate Base (CAB): 4 inches ARTIFICIAL FILL (Af) Silty Sand with Gravel (SM): Dark brown, moist, medium dense, fine to coarse gravel, fine to coarse sand, some clay Clayey Sand with Gravel (SC): Very dark brown, damp, medium dense, fine to coarse gravel, fine to coarse sand, few concrete fragments ft., increased gravel ALLUVIUM (Qal) Sand (SP): Pale brown, dry to damp, medium dense, fine to medium sand, friable 15 N.R. 15 ft., fine sand SA Hydro 20 ft., very light gray 13 Albus-Keefe & Associates, Inc. Plate A-5

24 E X P L O R A T I O N L O G Project: 1725 W. Katella Avenue, Orange Location: B-2 Address: 1735 W Katella Ave, Orange, CA Elevation: Job Number: Client: Branch West Date: 7/23/2016 Drill Method: Hollow-Stem Auger Driving Weight: 140 lbs / 30 in Logged By: AJA Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab 25 ft., dense, trace fine gravel ft., no gravel 26 Sandy Clay with Gravel (SC): Reddish brown, moist, hard, fine to coarse gravel, fine to coarse sand Boring ended at 36.5 feet. No groundwater encountered. Backfilled with cuttings. Patched with cold patch AC. Additional Boring Drilled adjacent and converted into 15-foot test well. Albus-Keefe & Associates, Inc. Plate A-6

25 E X P L O R A T I O N L O G Project: 1725 W. Katella Avenue, Orange Location: B-3 Address: 1735 W Katella Ave, Orange, CA Elevation: Job Number: Client: Branch West Date: 7/23/2016 Drill Method: Hollow-Stem Auger Driving Weight: 140 lbs / 30 in Logged By: AJA Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab Tests Asphalt Concrete (AC): 4 inches Crushed Aggregate Base (CAB): 3 inches ARTIFICIAL FILL (Af) Clayey Sand (SC): Very dark gray, moist, loose, fine sand Max EI SO4 DS ph Resist 2 ', interbedded pale brown sand, few fine 4 ', some brick fragments Silty Sand (SM): Dark brown, damp to moist, very loose, fine to medium sands, trace fine gravel, caliche stains ALLUVIUM (Qal) Sand (SP): Pale brown, damp, medium dense, medium to coarse sand, micaceous Sand with Silt (SP-SM): Pale brown, damp, medium dense, fine to coarse sand, micaceous Albus-Keefe & Associates, Inc. Plate A-7

26 E X P L O R A T I O N L O G Project: 1725 W. Katella Avenue, Orange Location: B-3 Address: 1735 W Katella Ave, Orange, CA Elevation: Job Number: Client: Branch West Date: 7/23/2016 Drill Method: Hollow-Stem Auger Driving Weight: 140 lbs / 30 in Logged By: AJA Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab Tests 10 Sandy Clay (CL): Olive brown, moist, stiff, fine sand, micaceous 20.2 Dist. Sand (SP): Pale brown, damp, medium dense, fine to coarse sand, micaceous Clay with Gravel (CL): Reddish brown, moist, hard, fine gravel, trace fine sand 13 Dist Dist. ATT Silty Sand with Gravel (SM): Strong brown, moist, very dense, fine to coarse gravel, fine to coarse sand, trace clay 40 ft., increased fines ft., increased gravel 79 Clay with Sand (CL): pale olive brown, moist, very stiff, fine sand Albus-Keefe & Associates, Inc. Plate A-8

27 E X P L O R A T I O N L O G Project: 1725 W. Katella Avenue, Orange Location: B-3 Address: 1735 W Katella Ave, Orange, CA Elevation: Job Number: Client: Branch West Date: 7/23/2016 Drill Method: Hollow-Stem Auger Driving Weight: 140 lbs / 30 in Logged By: AJA Depth (feet) Lithology Material Description Water Samples Blows Per Foot Core Bulk Moisture Content (%) Laboratory Tests Dry Density (pcf) Other Lab Tests Dist. Boring ended at 51.5 feet. No groundwater encountered. Backfilled with cuttings. Patched with cold patch AC. Albus-Keefe & Associates, Inc. Plate A-9

28 APPENDIX B LABORATORY TEST PROGRAM

29 Branch West August 24, 2016 Soil Classification LABORATORY TESTING PROGRAM Soils encountered within the exploratory borings were initially classified in the field in general accordance with the visual-manual procedures of the Unified Soil Classification System (Test Method ASTM D 2488). The samples were re-examined in the laboratory and classifications reviewed and then revised where appropriate. The assigned group symbols are presented in the Boring Logs, Appendix A. In-Situ Moisture Content and Dry Density Moisture content and dry density of in-place soil materials were determined in representative strata. Test data are presented on the Exploration Logs in Appendix A. Maximum Dry Density and Optimum Moisture Content Maximum dry density and optimum moisture content were performed on a representative sample of the site materials obtained from our field explorations. The test was performed in accordance with ASTM D Pertinent test values are given in Table B. Soluble Sulfate Content A chemical analysis was performed on a selected sample to determine soluble sulfate content. This test was performed in our soil laboratory in accordance with California Test Method No 417. The test result is included on Table B. Particle-Size Analyses Particle-size analyses were performed on selected samples in accordance with ASTM D 422. The results are presented graphically on the attached Plate B-1. Percent Passing the No. 200 Sieve Percent of material passing the No. 200 sieve was determined on selected samples to verify visual classifications performed in the field. These tests were performed in accordance with ASTM D Test results are presented on Table B. Direct Shear The Coulomb shear strength parameters, angle of internal friction and cohesion, were determined for a bulk sample obtained from one of our boring (remolded) and an intact (undisturbed) sample. The tests were performed in general conformance with ASTM D The bulk sample was remolded to 90 percent of maximum dry density. In both series of tests, three specimens were prepared for the test, artificially saturated, and then sheared under varied loads at an appropriate constant rate of strain. Results are graphically presented on Plates B-2 and B-3. Atterberg Limits Atterberg Limits (Liquid Limit, Plastic Limit, and Plasticity Index) were performed in accordance with Test Method ASTM D Pertinent test values are presented within Table B.

30 Branch West August 24, 2016 Expansion Potential An Expansion Index test was performed on a selected sample in accordance with ASTM D The test result and expansion potential are presented on Table B. Minimum Resistivity and ph A minimum resistivity test and a ph test were performed on a selected sample in our soil laboratory in accordance with California Test Method No 643. The tests results are included on Table B. TABLE B SUMMARY OF LABORATORY TEST RESULTS Boring No. Sample Depth (ft.) Soil Description B-1 26 Sandy Clay (CL) Test Results Liquid Limit: Plasticity Index: 35.6% 16.1% B-1 30 Sandy Clay (CL) Percent Passing #200 Sieve: 60.6% B-1 35 Sandy Clay (CL) Liquid Limit: Plasticity Index: 36.7% 21.0% B-1 36 Silty Sand with Gravel (SM) Percent Passing #200 Sieve: 25.0% B-1 50 Sandy-Silty Clay (CL) B Clayey Sand (SC) B-3 35 Lean Clay (CL) Liquid Limit: Plasticity Index: Maximum Dry Density: Optimum Moisture Content: Expansion Index: Expansion Potential: Soluble Sulfate: Sulfate Exposure: ph: Minimum Resistivity (ohm-cm): Liquid Limit: Plasticity Index: 22.1% 6.4% % 26 Low 0.003% Negligible % 26.2%

31 UNIFIED SOIL CLASSIFICATION COBBLES GRAVEL SAND COARSE FINE COARSE MEDIUM FINE SILT AND CLAY 100 U.S. STANDARD SIEVE SIZES 6" 3" 1.5" 3/4" 3/8" GRAIN SIZE DISTRIBUTION PERCENT PASSING PERCENT RETAINED Plate No: B-1 Job No: LOCATION SAMPLE SYMBOL GRAIN SIZE IN MILLIMETERS LL PI CLASSIFICATION

32 Specimen No. Normal Stress (ksf) Peak Stress (ksf) Peak Displacement (in) Ultimate Stress (ksf) Ultimate Displacement (in) Initial Dry Density Initial Moisture Content (%) Strain Rate (in/min) Vertical Displacement (in.) Axial Strain (%) Shear Stress (ksf) Axial Strain (%) Strain Legend 1 Ksf 2 Ksf 4 Ksf SHEAR STRESS (ksf) NORMAL STRESS (ksf) Strength Legend Peak Ultimate SAMPLE LOCATION SAMPLE TYPE SAMPLE DESCRIPTION 0-5 feet Remolded to 90% of 9.5% Clayey Sand (SC) Job No: DIRECT SHEAR Plate No: B-3

33 Specimen No. Normal Stress (ksf) Peak Stress (ksf) Peak Displacement (in) Ultimate Stress (ksf) Ultimate Displacement (in) Initial Dry Density Initial Moisture Content (%) Strain Rate (in/min) Vertical Displacement (in.) Axial Strain (%) Shear Stress (ksf) Axial Strain (%) Strain Legend 1 Ksf 2 Ksf 4 Ksf SHEAR STRESS (ksf) NORMAL STRESS (ksf) Strength Legend Peak Ultimate SAMPLE LOCATION SAMPLE TYPE SAMPLE DESCRIPTION 10 feet Undisturbed Sand (SP) Job No: DIRECT SHEAR Plate No: B-2