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HomeMy WebLinkAboutGeotech Report V16 April 2018 Page # 1 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION Mr. Kameron Nauahi Brighton Development, Inc. 12601 West Explorer Drive, Suite 200 Boise, ID 83713 208-378-4000 Re: Limited Geotechnical Engineering Report Pinnacle Subdivision Near Locust Grove Road and Lake Hazel Road Meridian, ID Dear Mr. Nauahi: In compliance with your instructions, MTI has conducted a limited soils exploration for the above referenced development. Fieldwork for this investigation was conducted on 21 and 23 March 2018. The proposed development is in the southern portion of the City of Meridian, Ada County, ID, and occupies a portion of Sections 31 and 32, Township 3 North, Range 1 East, and Sections 5 and 6, Township 2 North, Range 1 East, Boise Meridian. This project will consist of construction of a residential subdivision. Details of the proposed subdivision are unknown at this time. MTI has not been informed of the proposed grading plan. Authorization Authorization to perform this exploration and analysis was given in the form of a written authorization to proceed from Mr. Jonathan D. Wardle of Brighton Development, Inc. to Elizabeth Brown of Materials Testing and Inspection (MTI), on 5 March 2018. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between Brighton Development, Inc. and MTI. Our scope of services for the proposed development has been provided in our proposal dated 5 March 2018 and repeated below. Scope of Investigation The scope of this investigation included review of geologic literature and existing available geotechnical studies of the area, visual site reconnaissance of the immediate site, subsurface exploration of the site, field and laboratory testing of materials collected, and engineering analysis and evaluation of subsurface materials. Our scope of work did not include foundation design, pavement design, or earthwork recommendations. Regional Geology The project site is located within the western Snake River Plain of southwestern Idaho and eastern Oregon. The plain is a northwest trending rift basin, about 45 miles wide and 200 miles long, that developed about 14 million years ago (Ma) and has since been occupied sporadically by large inland lakes. Geologic materials found within and along the plain’s margins reflect volcanic and fluvial/lacustrine sedimentary processes that have led to an accumulation of approximately 1 to 2 km of interbedded volcanic and sedimentary deposits within the plain. 6 April 2018 Page # 2 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION Along the margins of the plain, streams that drained the highlands to the north and south provided coarse to fine-grained sediments eroded from granitic and volcanic rocks, respectively. About 2 million years ago the last of the lakes was drained and since that time fluvial erosion and deposition has dominated the evolution of the landscape. The project site is underlain by “Gravel of Amity Terrace” as mapped by Othberg and Stanford (1993). The Amity terrace is the fifth terrace above the modern Boise River and represents the first level of Quaternary incision by the Boise River. The terrace, which has been correlated with Deer Flat terrace deposits to the west, is modified extensively by erosion and faulting. Where little erosion has taken place the terrace is mantled with loess 1.6-7 feet thick. General Site Characteristics This proposed development consists of approximately 426 acres of gently rolling terrain in the northwest to relatively flat and level terrain from the central to southeastern portion of the site. Throughout the majority of the site, surficial soils consist of fine-grained clay-sand mixtures. Vegetation primarily consists of agricultural crop remnants, bunchgrass, and other native grass varieties typical of arid to semi-arid environments. The Farr Lateral trends northwest/southeast along the northern property boundary. In the central portion of the site, the McBirney Lateral trends west to east. The western and southern border of the site is bounded by the Rawson Canal. Regional drainage is north toward the Boise River. Stormwater drainage for the site is achieved by percolation through surficial soils. In the most northwestern portion of the property, intermittent off-site site stormwater may drain onto the site from the north. Stormwater drainage collection and retention systems are not in place on the project site and do not currently exist within the vicinity of the project site. Exploration and Sampling Procedures Field exploration conducted to determine engineering characteristics of subsurface materials included a reconnaissance of the project site and investigation by test pit. Test pit locations were predetermined by Brighton Construction and marked in the field. Test pit sites were located in the field by means of a Global Positioning System (GPS) device and are reportedly accurate to within ten feet. Upon completion of investigation, each test pit was backfilled with loose excavated materials. Re-excavation and compaction of these test pit areas are required prior to construction of overlying structures. In addition, samples were obtained from representative soil strata encountered. Samples obtained have been visually classified in the field by professional staff, identified according to test pit number and depth, placed in sealed containers, and transported to our laboratory for additional testing. Subsurface materials have been described in detail on logs provided in the Enclosures section. Results of field and laboratory tests are also presented in the Enclosures section. MTI recommends that these logs not be used to estimate fill material quantities. 6 April 2018 Page # 3 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION Laboratory Testing Program Along with our field investigation, a supplemental laboratory testing program was conducted to determine additional pertinent engineering characteristics of subsurface materials necessary in an analysis of anticipated behavior of the proposed structures. Laboratory tests were conducted in accordance with current applicable American Society for Testing and Materials (ASTM) specifications, and results of these tests are to be found on the accompanying logs located in the Enclosures section. The laboratory testing program for this report included: Atterberg Limits Testing – ASTM D4318 and Grain Size Analysis – ASTM C117/C136. Soil and Sediment Profile The profile below represents a generalized interpretation for the project site. Note that on site soils strata, encountered between test pit locations, may vary from the individual soil profiles presented in the logs, which can be found in the Enclosures section. The materials encountered during exploration were quite typical for the geologic area mapped as Gravel of Amity Terrace. Surficial soils were predominately lean clays; though sandy silty clay and borderline lean clay/fat clay was noted in test pits 3 and 16, respective. Clays were brown to dark brown or grey, dry to moist, soft to very stiff, and contained fine to coarse-grained sand. In test pit 12, gravels were also noted within the lean clays. In test pits 6 and 7, surficial materials were silty gravel fills and sandy organic silt fill, respectively. The fills were brown, dry, dense/very soft, and contained fine to coarse-grained sand and fine to coarse gravel. Below the surficial soils throughout most of the site were silty sands. These sediments were brown to light brown, dry to moist, medium dense to very dense, and contained fine to coarse-grained sand. At depth in most test pits were poorly graded sand with silt, poorly graded gravel with sand, and poorly graded gravel with silt and sand. These sediments were brown to light brown to tan, dry, very dense, and contains fine to coarse-sand, fine to coarse gravel, and 12-inch-minus cobbles. Test pit 16 met with refusal on basalt. This basalt was blackish, slightly weathered to fresh, very closely fractured, very strong to extremely strong, and contained vesicles. Competency of test pit walls varied little across the site. In general, fine grained soils remained stable while more granular sediments readily sloughed. However, moisture contents will also affect wall competency with saturated soils having a tendency to readily slough when under load and unsupported. Groundwater During this field investigation, groundwater was not encountered in test pits advanced to a maximum depth of 16.7 feet bgs. Soil moistures in the test pits were generally dry to moist within surficial soils and dry below. In the vicinity of the project site, groundwater levels are controlled in large part by residential and agricultural irrigation activity and leakage from nearby canals. Maximum groundwater elevations likely occur during the later portion of the irrigation season. During previous investigations performed in March 2013 and November 2015 within approximately ¼-mile to the west and south of the project site, groundwater was not encountered to depths as great as 10.5 to 16.6 feet bgs. 6 April 2018 Page # 4 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION For construction purposes, groundwater depth can be assumed to remain greater than 15 feet bgs throughout the year. However, leakage from the laterals on or adjacent to the site may influence groundwater levels. Since this is an estimated depth and seasonal groundwater levels fluctuate, actual levels should be confirmed by periodic groundwater data collected from piezometers installed in all the test pits. If desired, MTI is available to perform this monitoring. Soil Infiltration Rates Soil permeability, which is a measure of the ability of a soil to transmit a fluid, was not tested in the field. Given the absence of direct measurements, for this report an estimation of infiltration is presented using generally recognized values for each soil type and gradation. Of soils comprising the generalized soil profile for this study, lean/fat clay soils and sandy silty clay soils generally offer little permeability, with typical hydraulic infiltration rates of less than 2 inches per hour. Silty sand sediments usually display rates of 4 to 8 inches per hour; though calcium carbonate cementation may reduce this value to near zero. Poorly graded sand and gravel sediments typically exhibit infiltration values in excess of 12 inches per hour; though calcium carbonate cementation may reduce this value to near zero. Infiltration testing is generally not required within these sediments because of their free-draining nature. Ada County Highway District (ACHD) will require onsite percolation testing once the proposed locations of infiltration facilities are determined. The quantity of testing will be dependent on the size and number of infiltration facilities planned, and can be determined from Section 8000 of the ACHD Policy Manual. The estimated infiltration rates listed above are to be considered preliminary and are only provided to determine feasibility for onsite infiltration. Warranty and Limiting Conditions MTI warrants that findings and conclusions contained herein have been formulated in accordance with generally accepted professional engineering practice in the fields of foundation engineering, soil mechanics, and engineering geology only for the site and project described in this report. These engineering methods have been developed to provide the client with information regarding apparent or potential engineering conditions relating to the site within the scope cited above and are necessarily limited to conditions observed at the time of the site visit and research. Field observations and research reported herein are considered sufficient in detail and scope to form a reasonable basis for the purposes cited above. Exclusive Use This report was prepared for exclusive use of the property owner(s), at the time of the report, and their retained design consultants (“Client”). Conclusions and recommendations presented in this report are based on the agreed-upon scope of work outlined in this report together with the Contract for Professional Services between the Client and Materials Testing and Inspection (“Consultant”). Use or misuse of this report, or reliance upon findings hereof, by parties other than the Client is at their own risk. Neither Client nor Consultant make representation of warranty to such other parties as to accuracy or completeness of this report or suitability of its use by such other parties for purposes whatsoever, known or unknown, to Client or Consultant. Neither Client nor Consultant shall have liability to indemnify or hold harmless third parties for losses incurred by actual or purported use or misuse of this report. No other warranties are implied or expressed. 6 April 2018 Page # 5 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION Report Recommendations are Limited and Subject to Misinterpretation There is a distinct possibility that conditions may exist that could not be identified within the scope of the investigation or that were not apparent during our site investigation. Findings of this report are limited to data collected from noted explorations advanced and do not account for unidentified fill zones, unsuitable soil types or conditions, and variability in soil moisture and groundwater conditions. To avoid possible misinterpretations of findings, conclusions, and implications of this report, MTI should be retained to explain the report contents to other design professionals as well as construction professionals. Since actual subsurface conditions on the site can only be verified by earthwork, note that construction recommendations are based on general assumptions from selective observations and selective field exploratory sampling. Upon commencement of construction, such conditions may be identified that require corrective actions, and these required corrective actions may impact the project budget. Therefore, construction recommendations in this report should be considered preliminary, and MTI should be retained to observe actual subsurface conditions during earthwork construction activities to provide additional construction recommendations as needed. Since geotechnical reports are subject to misinterpretation, do not separate the soil logs from the report. Rather, provide a copy of, or authorize for their use, the complete report to other design professionals or contractors. Locations of exploratory sites referenced within this report should be considered approximate locations only. For more accurate locations, services of a professional land surveyor are recommended. This report is also limited to information available at the time it was prepared. In the event additional information is provided to MTI following publication of our report, it will be forwarded to the client for evaluation in the form received. Environmental Concerns Comments in this report concerning either onsite conditions or observations, including soil appearances and odors, are provided as general information. These comments are not intended to describe, quantify, or evaluate environmental concerns or situations. Since personnel, skills, procedures, standards, and equipment differ, a geotechnical investigation report is not intended to substitute for a geoenvironmental investigation or a Phase II/III Environmental Site Assessment. If environmental services are needed, MTI can provide, via a separate contract, those personnel who are trained to investigate and delineate soil and water contamination. General Comments Often questions arise concerning soil conditions because of design and construction details that occur on a project. MTI would be pleased to continue our role as geotechnical engineers during project implementation. Additionally, MTI would be pleased in providing materials testing and special inspection services during construction of this project. If you will advise us of the appropriate time to discuss these engineering services, we will be pleased to meet with you at your convenience. MTI appreciates this opportunity to be of service to you and looks forward to working with you in the future. If you have questions, please call (208) 376-4748. 6 April 2018 Page # 7 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL GENERAL NOTES RELATIVE DENSITY AND CONSISTENCY CLASSIFICATION Coarse-Grained Soils SPT Blow Counts (N) Fine-Grained Soils SPT Blow Counts (N) Very Loose: < 4 Very Soft: < 2 Loose: 4-10 Soft: 2-4 Medium Dense: 10-30 Medium Stiff: 4-8 Dense: 30-50 Stiff: 8-15 Very Dense: >50 Very Stiff: 15-30 Hard: >30 Moisture Content Cementation Description Field Test Description Field Test Dry Absence of moisture, dusty, dry to touch Weakly Crumbles or breaks with handling or slight finger pressure Moist Damp but not visible moisture Moderately Crumbles or beaks with considerable finger pressure Wet Visible free water, usually soil is below water table Strongly Will not crumble or break with finger pressure PARTICLE SIZE Boulders: >12 in. Coarse-Grained Sand: 5 to 0.6 mm Silts: 0.075 to 0.005 mm Cobbles: 12 to 3 in. Medium-Grained Sand: 0.6 to 0.2 mm Clays: <0.005 mm Gravel: 3 in. to 5 mm Fine-Grained Sand: 0.2 to 0.075 mm UNIFIED SOIL CLASSIFICATION SYSTEM Major Divisions Symbol Soil Descriptions Coarse-Grained Soils <50% passes No.200 sieve Gravel & Gravelly Soils <50% coarse fraction passes No.4 sieve GW Well-graded gravels; gravel/sand mixtures with little or no fines GP Poorly-graded gravels; gravel/sand mixtures with little or no fines GM Silty gravels; poorly-graded gravel/sand/silt mixtures GC Clayey gravels; poorly-graded gravel/sand/clay mixtures Sand & Sandy Soils >50% coarse fraction passes No.4 sieve SW Well-graded sands; gravelly sands with little or no fines SP Poorly-graded sands; gravelly sands with little or no fines SM Silty sands; poorly-graded sand/gravel/silt mixtures SC Clayey sands; poorly-graded sand/gravel/clay mixtures Fine Grained Soils >50% 6 April 2018 Page # 8 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION ROCK CLASSIFICATION SYSTEM WEATHERING WEATHERING FIELD TEST Fresh No sign of decomposition or discoloration. Rings under hammer impact. Slightly Weathered Slight discoloration inwards from open fractures, otherwise similar to Fresh. Moderately Weathered Discoloration throughout. Weaker minerals such as feldspar decomposed. Strength somewhat less than fresh rock but cores cannot be broken by hand or scraped with a knife. Texture preserved. Highly Weathered Most minerals somewhat decomposed. Specimens can be broken by hand with effort or shaved with knife. Core stones present in rock mass. Texture becoming indistinct but fabric preserved. Completely Weathered Minerals decomposed to soil but fabric and structure preserved. Specimens easily crumbled or penetrated. FRACTURING ROCK QUALITY DESIGNATION (RQD) SPACING DISCRIPTION RQD (%) ROCK QUALITY 6 ft. 2 – 6 ft. 8 – 24 in. 2 ½ - 8 in. ¾ - 2 ½ in. Very widely Widely Moderately Closely Very Closely 90 – 100 75 – 90 50 – 75 25 – 50 0 - 25 Excellent Good Fair Poor Very Poor COMPETENCY STRENGTH CLASS FIELD TEST APPROXIMATE RANGE OF UNCONFINED COMPRESSIVE STRENGTH (tsf) Extremely Strong I Many blows with geologic hammer required to break intact specimen. >2000 Very Strong II Hand-held specimen breaks with pick end of hammer under more than one blow. 2000 - 1000 Strong III Cannot be scraped or peeled with knife, hand-held specimen can be broken with single moderate blow 6 April 2018 Page # 9 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-1 Date Advanced: 21 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5567614 Longitude: -116.3878797 Depth to Water Table: Not Encountered Total Depth: 7.0 Feet bgs Notes: Piezometer installed to 7.0 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-3.2 Lean Clay (CL): Brown, dry to slightly moist, stiff to very stiff. GS 2.0-2.5 1.25-2.5 A 3.2-5.4 Silty Sand (SM): Brown to light brown, dry, very dense, with fine to coarse-grained sand. --Weak to moderate calcium carbonate cementation noted throughout. 5.4-7.0 Poorly Graded Sand with Silt (SP-SM): Brown, dry, very dense, with fine to coarse- grained sand. --Moderate to strong induration throughout. --Fine to coarse gravel noted from 6.5 to 7.0 feet bgs. --Refusal because of strong induration. Lab Test ID M LL PI Sieve Analysis (% passing) - % - - #4 #10 #40 #100 #200 A 27.3 43 28 100 100 98 96 91.4 6 April 2018 Page # 10 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-2 Date Advanced: 21 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5537091 Longitude: -116.3842380 Depth to Water Table: Not Encountered Total Depth: 16.4 Feet bgs Notes: Piezometer installed to 16.4 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-2.5 Lean Clay (CL): Brown to dark brown, dry, medium stiff to very stiff, with fine-grained sand. --Organic and plow zone noted to 1.3 feet bgs. 1.0-2.25 2.5-16.4 Poorly Graded Gravel with Sand (GP): Light brown to tan, dry, very dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch-minus cobbles. --Strong calcium carbonate cementation noted from 2.5 to 7.0 feet bgs. 6 April 2018 Page # 11 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-3 Date Advanced: 21 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5537725 Longitude: -116.3790808 Depth to Water Table: Not Encountered Total Depth: 13.7 Feet bgs Notes: Piezometer installed to 13.7 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-3.7 Sandy Silty Clay (CL-ML): Brown, dry, very stiff, with fine-grained sand. --Organics noted to 2.0 feet bgs. GS 2.5-3.0 2.25-4.0 B 3.7-8.0 Silty Sand (SM): Light brown, dry, very dense, with fine to coarse-grained sand. --Strong calcium carbonate cementation noted throughout. 8.0-13.7 Poorly Graded Gravel with Sand (GP): Brown, dry, very dense, with fine to coarse- grained sand, fine to coarse gravel, and 11- inch-minus cobbles. Lab Test ID M LL PI Sieve Analysis (% passing) - % - - #4 #10 #40 #100 #200 B 23.2 26 6 100 95 84 76 69.6 6 April 2018 Page # 12 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-4 Date Advanced: 21 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.553776 Longitude: -116.3761296 Depth to Water Table: Not Encountered Total Depth: 14.7 Feet bgs Notes: Piezometer installed to 14.7 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.7 Lean Clay (CL): Brown, dry, very stiff, with fine-grained sand. --Organics noted to 0.5 foot bgs. 2.25- 3.25 1.7-14.7 Silty Sand (SM): Brown, dry, very dense, with fine to coarse-grained sand. --Weak to moderate calcium carbonate cementation noted throughout. --Silt content decreases with depth below 6.0 feet bgs. 6 April 2018 Page # 13 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-5 Date Advanced: 21 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5534931 Longitude: -116.3799381 Depth to Water Table: Not Encountered Total Depth: 15.7 Feet bgs Notes: Piezometer installed to 15.7 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-3.4 Lean Clay (CL): Dark brown to brown, dry, stiff to very stiff, with fine-grained sand. --Organics noted to 0.3 foot bgs. GS 2.0-3.0 2.0-3.0 C 3.4-15.7 Poorly Graded Gravel with Sand (GP): Brown, dry, very dense, with fine to coarse- grained sand, fine to coarse gravel, and 6- inch-minus cobbles. --Strong calcium carbonate cementation noted from 3.4 to 5.0 feet bgs. Lab Test ID M LL PI Sieve Analysis (% passing) - % - - #4 #10 #40 #100 #200 C 20.7 39 25 100 98 95 92 88.5 6 April 2018 Page # 14 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-6 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5519963 Longitude: -116.3841857 Depth to Water Table: Not Encountered Total Depth: 12.6 Feet bgs Notes: Piezometer installed to 12.6 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.9 Silty Gravel Fill (GM-FILL): Brown, dry, dense, with fine to coarse-grained sand and fine to coarse gravel. --Organics noted to 0.5 foot bgs. 1.9-5.2 Silty Sand (SM): Light brown, dry, very dense, with fine to coarse-grained sand. --Strong calcium carbonate cementation noted throughout. 5.2-12.6 Poorly Graded Gravel with Sand (GP): Brown, dry, dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 12-inch-minus cobbles. 6 April 2018 Page # 15 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-7 Date Advanced: 21 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5517270 Longitude: -116.3709335 Depth to Water Table: Not Encountered Total Depth: 15.4 Feet bgs Notes: Piezometer installed to 15.4 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.6 Sandy Organic Silt Fill (OL-FILL): Dark brown, dry, very soft, with fine to coarse- grained sand. --Organics noted throughout. --A hard clay pocket was noted in eastern portion of the test pit. 0.0 1.6-4.0 Silty Sand (SM): Light brown, dry, very dense, with fine to coarse-grained sand. 4.0-15.4 Poorly Graded Gravel with Sand (GP): Brown, dry, very dense, with fine to coarse- grained sand, fine to coarse gravel, and 11- inch-minus cobbles. 6 April 2018 Page # 16 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-8 Date Advanced: 21 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5500625 Longitude: -116.3743195 Depth to Water Table: Not Encountered Total Depth: 16.3 Feet bgs Notes: Piezometer installed to 16.3 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.2 Lean Clay (CL): Brown, dry, stiff to very stiff, with fine to coarse-grained sand. --Organics and plow zone noted throughout. 1.5-2.25 1.2-4.0 Silty Sand (SM): Light brown, dry, very dense, with fine to coarse-grained sand. --Strong calcium carbonate cementation noted throughout. 4.0-16.3 Poorly Graded Gravel with Sand (GP): Brown, dry, very dense, with fine to coarse- grained sand, fine to coarse gravel, and 12- inch-minus cobbles. 6 April 2018 Page # 17 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-9 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5485960 Longitude: -116.3843094 Depth to Water Table: Not Encountered Total Depth: 16.0 Feet bgs Notes: Piezometer installed to 16.0 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-2.6 Lean Clay (CL): Dark brown, dry, stiff, with fine-grained sand. --Organics and plow zone noted to 1.0 foot bgs. GS 1.5-2.0 1.25 D 2.6-10.8 Silty Sand (SM): Light brown, dry to moist, very dense, with fine to coarse-grained sand. --Strong calcium carbonate cementation noted from 2.6 to 3.2 feet bgs and weak to moderate calcium carbonate cementation from 3.2 to 4.0 feet bgs. 10.8-16.0 Poorly Graded Gravel with Sand (GP): Brown, dry, dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 11-inch-minus cobbles. Lab Test ID M LL PI Sieve Analysis (% passing) - % - - #4 #10 #40 #100 #200 D 24.3 38 21 100 100 99 97 92.3 6 April 2018 Page # 18 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-10 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5467287 Longitude: -116.3812413 Depth to Water Table: Not Encountered Total Depth: 16.7 Feet bgs Notes: Piezometer installed to 16.7 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-3.0 Lean Clay (CL): Greyish to dark brown, moist, stiff to very stiff, with fine to coarse- grained sand. --Organics noted to 0.8 foot bgs. --Plow zone noted to 1.6 feet bgs. GS 1.5-2.0 1.5-2.5 E 3.0-15.0 Silty Sand (SM): Brown to light brown, dry, very dense, with fine to coarse-grained sand. --Strong calcium carbonate cementation noted from 3.0 to 4.0 feet bgs and weak to moderate calcium carbonate cementation from 4.0 to 15.0 feet bgs. --Color change to orange-brown in the weak to moderate cementation. 15.0-16.7 Poorly Graded Gravel with Silt and Sand (GP-GM): Brown, dry, very dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch-minus cobbles. Lab Test ID M LL PI Sieve Analysis (% passing) - % - - #4 #10 #40 #100 #200 E 23.5 42 27 100 100 98 94 88.0 6 April 2018 Page # 19 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-11 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.546588 Longitude: -116.374618 Depth to Water Table: Not Encountered Total Depth: 5.3 Feet bgs Notes: Piezometer installed to 5.3 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-2.5 Lean Clay (CL): Brown, dry to slightly moist, stiff to very stiff, with fine to coarse-grained sand. --Organics and plow zone noted to 1.4 feet bgs. GS 1.5-2.0 1.5-2.75 F 2.5-5.3 Silty Sand (SM): Light brown, dry, very dense, with fine to coarse-grained sand. --Strong calcium carbonate cementation noted from 3.0 to 5.3 feet bgs. --Refusal because of strong calcium carbonate cementation. Lab Test ID M LL PI Sieve Analysis (% passing) - % - - #4 #10 #40 #100 #200 F 23.5 41 28 99 99 96 93 86.3 6 April 2018 Page # 20 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-12 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5474874 Longitude: -116.3696310 Depth to Water Table: Not Encountered Total Depth: 14.3 Feet bgs Notes: Piezometer installed to 14.3 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.6 Sandy Lean Clay with Gravel (CL): Brown, moist, soft to stiff, with fine to coarse-grained sand. --Organics and plow zone noted throughout. GS 1.0-1.5 0.5-1.5 G 1.6-3.2 Silty Sand (SM): Light brown, moist, very dense, fine to coarse-grained sand. --Strong calcium carbonate cementation noted throughout. 3.2-14.3 Poorly Graded Gravel with Sand (GP): Light brown, dry, very dense, with fine to coarse- grained sand, fine to coarse gravel, and 8- inch-minus cobbles. Lab Test ID M LL PI Sieve Analysis (% passing) - % - - #4 #10 #40 #100 #200 G 23.2 36 14 74 71 63 59 54.6 6 April 2018 Page # 21 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-13 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5463032 Longitude: -116.3695116 Depth to Water Table: Not Encountered Total Depth: 3.8 Feet bgs Notes: Piezometer installed to 3.8 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.8 Sandy Lean Clay (CL): Brown, moist, medium stiff to very stiff, with fine to coarse- grained sand. --Organics and plow zone noted throughout. 1.0-2.25 1.8-3.8 Silty Sand (SM): Light brown, dry to slightly moist, very dense, with fine to coarse-grained sand. --Strong calcium carbonate cementation noted throughout. --Refusal because of strong cementation. 6 April 2018 Page # 22 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-14 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5451562 Longitude: -116.3756314 Depth to Water Table: Not Encountered Total Depth: 14.0 Feet bgs Notes: Piezometer installed to 14.0 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.4 Lean Clay with Sand (CL): Brown, moist, stiff to very stiff, with fine to coarse-grained sand. --Plow zone noted to 0.7 foot bgs. 1.5-3.75 1.4-12.6 Silty Sand (SM): Brown to light brown, dry to slightly moist, very dense, with fine to coarse-grained sand. --Strong calcium carbonate cementation noted from 3.8 to 5.2 feet bgs and weak to moderate calcium carbonate cementation from 5.2 to 12.6 feet bgs. 12.6-14.0 Poorly Graded Gravel with Silt and Sand (GP-GM): Red brown, dry, very dense, with fine to coarse-grained sand, fine to coarse gravel, and 7-inch-minus cobbles. 6 April 2018 Page # 23 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-15 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.542059 Longitude: -116.3694040 Depth to Water Table: Not Encountered Total Depth: 11.7 Feet bgs Notes: Piezometer installed to 11.7 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.0 Lean Clay (CL): Brown, moist, stiff to very stiff, with fine to coarse-grained sand. --Plow zone noted to 0.7 foot bgs. 1.5-3.75 1.0-9.5 Silty Sand (SM): Brown to light brown, dry to slightly moist, very dense, with fine to coarse-grained sand. --Weak to moderate calcium carbonate cementation noted from 3.8 to 5.2 feet bgs. 9.5-11.7 Poorly Graded Gravel with Silt and Sand (GP-GM): Brown, dry, very dense, with fine to coarse-grained sand, fine to coarse gravel, and 12-inch-minus cobbles. --Refusal on large rounded boulders. 6 April 2018 Page # 24 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-16 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5413676 Longitude: -116.3774194 Depth to Water Table: Not Encountered Total Depth: 14.5 Feet bgs Notes: Piezometer installed to 14.5 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-2.0 Borderline Fat Clay/Lean Clay (CH/CL): Brown, slightly moist, stiff to very stiff, with fine to coarse-grained sand. --Organics and plow zone noted to 1.5 feet bgs. GS 1.6-2.0 1.5-2.0 H 2.0-14.5 Silty Sand (SM): Brown to light brown, dry, very dense, with fine to coarse-grained sand. --Weak to moderate calcium carbonate cementation noted from 3.8 to 5.2 feet bgs. Below 14.5 Basalt: Blackish, slightly weathered to fresh, very closely fractured, very strong to extremely strong, with vesicles. Lab Test ID M LL PI Sieve Analysis (% passing) - % - - #4 #10 #40 #100 #200 H 27.5 50 34 100 100 100 99 95.7 6 April 2018 Page # 25 of 27 b180364g_limitedgeo  Environmental Services  Geotechnical Engineering  Construction Materials Testing  Special Inspections 2791 S Victory View Way  Boise, ID 83709  (208) 376-4748  Fax (208) 322-6515 www.mti-id.com  mti@mti-id.com Copyright © 2018 Materials Testing & Inspection MATERIALS TESTING & INSPECTION GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-17 Date Advanced: 23 Mar 2018 Logged by: Maren Tanberg, E.I.T. Excavated by: Struckman’s Backhoe Service Location: See Site Map Plates Latitude: 43.5391781 Longitude: -116.3740623 Depth to Water Table: Not Encountered Total Depth: 16.5 Feet bgs Notes: Piezometer installed to 16.5 feet bgs. Depth (Feet bgs) Field Description and USCS Soil and Sediment Classification Sample Type Sample Depth (Feet bgs) Qp Lab Test ID 0.0-1.7 Lean Clay (CL): Brown, slightly moist, stiff to very stiff, with fine to coarse-grained sand. --Organics and plow zone noted to 1.0 foot bgs. 1.5-4.0 1.7-16.5 Silty Sand (SM): Brown to light brown, dry, medium dense to very dense, with fine to coarse-grained sand. --Weak to moderate calcium carbonate cementation noted throughout. with pick end of hammer. 1000 - 500 Moderately Strong IV Can just be scraped or peeled with knife. Indentations 1 mm to 3 mm show in specimen with moderate blow with pick end of hammer. 500 - 250 Weak V Material crumbles under moderate blow with pick end of hammer and can be peeled with a knife, but is hard to hand-trim for tri-axial test specimen. 250 - 10 Friable VI Material crumbles in hand. N/A passes No.200 sieve Silts & Clays LL < 50 ML Inorganic silts; sandy, gravelly or clayey silts CL Lean clays; inorganic, gravelly, sandy, or silty, low to medium-plasticity clays OL Organic, low-plasticity clays and silts Silts & Clays LL > 50 MH Inorganic, elastic silts; sandy, gravelly or clayey elastic silts CH Fat clays; high-plasticity, inorganic clays OH Organic, medium to high-plasticity clays and silts Highly Organic Soils PT Peat, humus, hydric soils with high organic content