Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
Ex_06_Geotech_Report
ATTACHMENT 23: GEOTECHNICAL REPORT Exhibit 6 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GEOTECHNICAL REPORT RENTON MUNICIPAL AIRPORT GA APRON REHABILITATION RENTON, WASHINGTON HWA Project No. 2023-055-21 November 2, 2023 Prepared for DOWL Engineering Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 21312 30th Dr. SE, STE. 110, Bothell, WA 98021 | 425.774.0106 | hwageo.com November 2, 2023 HWA Project No. 2023-055-21 DOWL Engineering 8410 154th Avenue NE, Suite 120 Redmond, Washington 98052 Attention: Wes Holden, P.E. Subject: GEOTECHNICAL REPORT Renton Municipal Airport GA Apron Rehabilitation Renton, Washington Mr. Holden: As authorized, HWA GeoSciences Inc. (HWA) has completed a geotechnical and pavement engineering study for the GA Apron Rehabilitation project at the Renton Municipal Airport in Renton, Washington. Our scope of work included logging the drilling of 7 geotechnical borings, performing pavement coring at 7 locations, performing Falling Weight Deflectometer (FWD) testing, laboratory testing, engineering analyses, and preparation of the attached report summarizing the investigation results and our recommendations. The work was performed to provide recommendations for rehabilitation of the GA Apron at Renton Municipal Airport. We appreciate the opportunity to provide geotechnical services on this project. Sincerely, HWA GEOSCIENCES INC. Seth Pemble, L.G. Bryan K. Hawkins, P.E. Geologist Senior Geotechnical Engineer Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 Renton Municipal Airport – GA Apron Rehabilitation i HWA GEOSCIENCES INC. TABLE OF CONTENTS 1.0 INTRODUCTION ..........................................................................................................1 1.1 GENERAL .......................................................................................................1 1.2 PROJECT UNDERSTANDING ............................................................................1 2.0 FIELD INVESTIGATION AND LABORATORY TESTING ..................................................2 2.1 DRILLED BORINGS .........................................................................................2 2.2 PAVEMENT CORING .......................................................................................2 2.3 FALLING WEIGHT DEFLECTOMETER TESTING ...............................................4 2.4 LABORATORY TESTING .................................................................................5 3.0 SITE CONDITIONS ......................................................................................................6 3.1 SITE DESCRIPTION .........................................................................................6 3.2 GENERAL GEOLOGY ......................................................................................6 3.3 SUBSURFACE CONDITIONS ............................................................................7 3.4 GROUNDWATER CONDITIONS ........................................................................7 4.0 CONCLUSIONS AND RECOMMENDATIONS ..................................................................8 4.1 GENERAL .......................................................................................................8 4.2 FROST CONDITIONS .......................................................................................8 4.3 DRAINAGE .....................................................................................................8 4.4 WET WEATHER EARTHWORK ........................................................................8 4.5 TEMPORARY EXCAVATIONS ..........................................................................9 5.0 CONDITIONS AND LIMITATIONS .................................................................................9 REFERENCES .........................................................................................................11 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 Renton Municipal Airport – GA Apron Rehabilitation ii HWA GEOSCIENCES INC. LIST OF FIGURES (FOLLOWING TEXT) Figure 1 Site & Vicinity Map Figures 2A & 2B Site and Exploration Plans Figure 3 FWD Test Results – GA Apron Maximum Deflections Figure 4 FWD Test Results – GA Apron Subgrade Resilient Moduli APPENDICES Appendix A: Field Exploration Figure A-1 Legend of Terms and Symbols Used on Exploration Logs Figures A-2 – A-8 Logs of Pavement Cores Core-1 through Core-6 Figure A-9 – A-15 Logs of Borings BH-1 through BH-7 Appendix B: Laboratory Test Results Figures B-1 Summary of Material Properties Figures B-2 – B-5 Particle Size Analysis of Soils Figures B-6 Liquid Limit, Plastic Limit, and Plasticity Index of Soils Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GEOTECHNICAL REPORT RENTON MUNICIPAL AIRPORT GA APRON REHABILITATION RENTON, WASHINGTON 1.0 INTRODUCTION 1.1 GENERAL This report summarizes the results of a geotechnical investigation undertaken by HWA GeoSciences at Renton Municipal Airport in Renton, Washington, in support of the design and construction of the GA Apron Rehabilitation project. Our scope of work included: • Logging the drilling of 7 geotechnical borings to a depth of about 11.5 feet each. • Performing pavement coring at 7 locations along with shallow excavations through each core hole using hand digging equipment. • Performing Falling Weight Deflectometer testing at GA Apron. • Performing laboratory testing consisting of natural moisture content testing, grain size analyses, Atterberg Limits, and organic content. • Performing engineering analyses pertaining to the proposed improvements and development of this report. The general project location is shown on the Site & Vicinity Map, Figure 1. The locations of our drilled boring and pavement core explorations are shown on the Site and Exploration Plans, Figures 2A and 2B. 1.2 PROJECT UNDERSTANDING We understand that Renton Municipal Airport plans to rehabilitate/reconstruct the pavement at the GA Apron, covering an area of approximately 7,200 square yards. Existing pavement demolition, subgrade stabilization, various drainage improvements, and new pavement consisting of either Portland Cement Concrete (PCC), or Hot Mix Asphalt (HMA) are proposed for this project. Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 2 HWA GEOSCIENCES INC. 2.0 FIELD INVESTIGATION AND LABORATORY TESTING 2.1 DRILLED BORINGS On August 28, 2023, HWA logged the drilling of 4 geotechnical borings at the GA Apron (Figure 2A) and 3 geotechnical borings in parking areas southwest of Taxiway A (Figure 2B) to assess pavement layer thicknesses and subsurface soil and groundwater conditions. The borings were drilled by Holocene Drilling, of Puyallup, Washington, under subcontract to HWA, using a Mobile B-58 truck-mounted drill rig using hollow stem auger drilling techniques. Standard Penetration Test (SPT) sampling was performed directly below the pavement and at depths of approximately 2.5, 5, 7.5 and 10 feet below pavement surface in each of the borings. The SPT resistance (“N-value”) of the soil was logged during each test. Standard Penetration Testing (SPT) was performed using a 2-inch outside diameter split-spoon sampler driven by a 140-pound hammer with an automatic hammer. During the tests, samples were obtained by driving the sampler 18 inches into the soil with the hammer free-falling 30 inches. The number of blows required for each 6-inches of penetration was recorded. This resistance, or N-value, provides an indication of relative density of granular soils and the relative consistency of cohesive soils. A geologist from HWA logged the explorations and recorded pertinent information, including sample depths, stratigraphy, soil descriptions, and groundwater occurrence. Soil samples obtained from the explorations were classified in the field and representative portions were placed in plastic bags. These soil samples were then taken to our Bothell, Washington, laboratory for further examination and testing. Soils were classified in general accordance with the American Society for Testing and Materials (ASTM) classification system. The summary boring logs are presented in Appendix A, Figures A-9 through A-15. The stratigraphic contacts shown on the exploration logs represent the approximate boundaries between soil types; actual transitions may be more gradual. The soil and groundwater conditions depicted are only for the specific date and location reported and, therefore, are not necessarily representative of other locations and times. 2.2 PAVEMENT CORING Pavement coring was performed on August 21, 2023, at 7 locations on the GA Apron. Pavement core locations are shown in Figure 2A. Pavement coring was performed using a 6-inch diameter, trailer hitch mounted, electric core drill to evaluate HMA pavement thickness, HMA lift thickness and depth of cracking. Shallow excavations to depths of about 0.6 to 5 feet below pavement surface were completed below each pavement core, using hand digging equipment, to assess crushed aggregate base thickness and shallow subgrade support conditions. Two geologists and a geotechnical engineer from HWA completed the pavement coring and shallow Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 3 HWA GEOSCIENCES INC. excavations. Samples of the crushed aggregate base and subgrade soils were collected during excavations. Pavement core holes were backfilled with material that was excavated from the hole and compacted in lifts. Pavement patching at the surface was completed by compacting water activated Aquaphalt 6.0 permanent pavement repair material. The thickness of the pavement patch material matched or exceeded the thickness of the existing HMA layer. Table 1 summarizes the pavement structure encountered at the location of pavement cores and drilled borings. Table 1. Summary of Pavement Structure Core Designation HMA Thickness (in.) Crushed Aggregate Base Thickness (in.) PCC Thickness (in.) Granular Fill Thickness (in.) Notes Core-1 3 4 - 6 Loose sand subgrade. Core-2 2.75 4.25 - - Vertical steel embedded in PCC below CSBC. Core-2A 2.5 4 4 - Terminated in CSBC below PCC at a depth of 13 inches. Core-3 2.25 4.25 - 5 Medium stiff to soft silt subgrade with peat and organics. Core-4 2 2 - - Medium stiff to soft silt subgrade. Core-5 2 1 - 7 Old asphalt material encountered from 10 to 13.25 inches above a 0.75-inch- thick layer of cementitious silt with dense gravel below. Core-6 2.25 5.25 - 12.5+ Excavation terminated in dense gravel fill at a depth of 20 inches. BH-1 2.75 - - 5 Soft, gray silt with sand subgrade. Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 4 HWA GEOSCIENCES INC. BH-2 3.25 - 4.25 - Very soft, organic silt subgrade. BH-3 2.5 - - 9.5 Very soft silt subgrade. BH-4 2.5 - - - Loose to very loose silty sand subgrade. BH-5 - - 6 - Loose, clean to silty sand subgrade. BH-6 1.5 - - - Loose sand with silt subgrade. BH-7 1.5 - - - Loose gravel and silty sand subgrade. 2.3 FALLING WEIGHT DEFLECTOMETER TESTING Falling Weight Deflectometer (FWD) testing was conducted on the GA Apron on August 21, 2023, within the project limits. Testing along the GA Apron was completed at approximate spacings of 20 feet in an approximately grid pattern where access between parked aircraft was available. Global Positioning System (GPS) readings were taken at each test location. Figure 3 presents color contoured maximum deflections (immediately under the applied load), normalized to a load of 9,000 pounds, for each test location. Figure 4 presents color contoured subgrade resilient modulus values for each test location. The FWD testing was undertaken using a Dynatest Model 8012 Fast Falling Weight Deflectometer. This FWD allows the pavement to be tested under a wide range of loading conditions (6,500 to 27,000 pounds) to simulate a variety of traffic loads. For this project, pulse loads of approximately 6,000, 9,000 and 12,000 pounds were applied to the pavement surface at each test location. The corresponding pavement surface deflections were measured with velocity transducers located directly under the loaded area, and at 8,12, 18, 24, 36, 48, 60, and 72 inches from the center of the loaded area. Table 2 summarizes the FWD deflection data for the GA Apron. Table 2. Maximum Deflection Normalized to 9,000-pound Load – GA Apron Location Number of Tests Average Maximum Deflection, mils Standard Deviation, mils Highest Deflection in Segment, mils Lowest Deflection in Segment, mils GA Apron 131 47.6 17.8 95.2 12.5 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 5 HWA GEOSCIENCES INC. Table 3 summarizes the backcalculated subgrade resilient moduli values for the GA Apron. The program BAKFAA was used for backcalculation of the surface layer, base layer and subgrade resilient moduli. Backcalculation was performed by inputting pavement layer thickness obtained from pavement coring. Table 3. Backcalculated Subgrade Resilient Modulus – GA Apron Location Number of Tests Average Subgrade Resilient Modulus, ksi Standard Deviation, ksi Highest Value, ksi Lowest Value, ksi GA Apron 131 8.0 3.8 38.5 3.3 The subgrade resilient moduli values are consistent with very soft to soft silt and very loose to loose, silty sand. Most of the highest subgrade resilient moduli values are located near the access road to the east where additional granular fill may have been placed during past improvements. 2.4 LABORATORY TESTING Representative soil samples obtained from the drilled borings and pavement core explorations were taken to the HWA laboratory for examination and testing. Laboratory tests were conducted on selected soil samples from the drilled borings to characterize engineering properties of the soils. Laboratory tests, as described below, included moisture and visual description, grain size distribution, Atterberg limits and organic content. The results of the laboratory testing are presented in Appendix B. Moisture Content of Soil: The moisture content (percent by dry mass) of selected soil samples was determined in general accordance with ASTM D2216. The results are shown at the sampled intervals on the appropriate exploration logs in Appendix A and on the Summary of Materials Properties report, Figure B-1. Particle Size Analysis of Soils: The particle size distribution of selected soil samples from the drilled borings were determined in general accordance with ASTM D6913. The results are summarized on the attached Particle Size Analysis of Soils reports, Figures B-2 through B-5, which also provide information regarding the classification of the samples and the moisture content at the time of testing. Liquid Limit, Plastic Limit, and Plasticity Index of Soils (Atterberg Limits): Four samples were tested using method ASTM D4318, multi-point method. The results are reported on the attached Liquid Limit, Plastic Limit, and Plasticity Index of Soils report, Figure B-6 along with the classification of the samples and the moisture content at the time of testing. Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 6 HWA GEOSCIENCES INC. Organic Content – Loss on Ignition: One sample was selected to determine organic content per ASTM D2974. The results are shown at the sampled intervals on the appropriate exploration log in Appendix A and on the Summary of Materials Properties report, Appendix B, Figure B-1. 3.0 SITE CONDITIONS 3.1 SITE DESCRIPTION The GA Apron is located at the eastern side of Renton Municipal Airport and adjoins the middle portion of Taxiway B. The Cedar River flows north immediately east of GA Apron and into Lake Washington at the northeast corner of the airport. The site is generally flat aside from minor sloping for surface water drainage. Pavement surfacing consists of HMA. Areas of high severity pavement distress, consisting of alligator cracking, exist near the middle and western half of the GA Apron. Other areas of HMA pavement near the existing hangars to the north and near the Cedar River Levee to the east exhibit low to medium severity longitudinal and transverse cracking. In addition to our investigations at the GA Apron site, we were requested to perform 3 additional borings (BH-5 through BH-7) at a second site located in the southwest corner of Renton Municipal Airport southwest of Taxiway A. The pavement surfacing consists mostly of HMA, with an area of PCC panels south of the hangar. We understand that drainage improvements were installed within the last few years to alleviate ponding water in the area paved with PCC pavement. The GA Apron is in a historic wetland and floodplain of the Cedar and Black Rivers that has been used as agricultural land, lumber mills, and more recently an airport. The second site included in this project is located where the Cedar River historically flowed into the Black River. The Black River is now filled in and/or diverted into underground culverts. The Cedar River was rerouted to flow north along the eastern edge of the Renton Municipal Airport into the southern end of Lake Washington. 3.2 GENERAL GEOLOGY The project site is located within the Puget Lowland. The Puget Lowland has repeatedly been occupied by a portion of the continental glaciers that developed during the ice ages of the Quaternary period. During at least four periods, portions of the ice sheet advanced south from British Columbia into the lowlands of Western Washington. The southern extent of these glacial advances was near Olympia, Washington. Each major advance included numerous local advances and retreats, and each advance and retreat resulted in its own sequence of erosion and deposition of glacial lacustrine, outwash, till, and drift deposits. Between and following these glacial advances, sediments from the Olympic and Cascade Mountains accumulated in the Puget Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 7 HWA GEOSCIENCES INC. Lowland. As the most recent glacier retreated, it uncovered a sculpted landscape of elongated, north-south trending hills and valleys between the Cascade and Olympic Mountain ranges, composed of a complex sequence of glacial and interglacial deposits. Geologic information for the project area was obtained from the Washington State Department of Natural Resources Geologic Information Portal. According to this map, the project site soils are mapped as artificial fill, modified land, and Quaternary alluvium deposited by the Cedar River and Black River. 3.3 SUBSURFACE CONDITIONS Subsurface conditions encountered in the explorations were different at the two sites evaluated. The GA Apron site is primarily underlain by subgrade soils consisting of soft to very soft silt and loose to very loose, silty sand. The HMA thickness varied from about 2 to 3 inches in thickness with varying layers below, as indicated on the exploration logs. Portland Cement Concrete (PCC) was encountered immediately below the HMA at the location of BH-2. PCC was encountered below an approximately 4-inch-thick layer of CSBC below the HMA surface at the locations of Core-2 and Core-2A. All three of these explorations are located in the northwest corner of the site. Subsurface conditions near the southwest corner of Taxiway A encountered loose, silty sand and gravel below the existing pavement section. 3.4 GROUNDWATER CONDITIONS At the GA Apron site, groundwater seepage was encountered in the alluvium at the locations of Core-1 and Core-3 at depths of 4.5 and 3.9 feet below ground surface, respectively. At the locations of borings BH-1 through BH-4, groundwater seepage was encountered at depths of 5 to 6 feet below ground surface. Borings located at the southwest corner of the airport, BH-5 through BH-7, encountered groundwater seepage at depths of 8 to 10 feet below ground surface. We anticipate the groundwater levels are highest near the end of the wet winter months and lower during the dry summer months. Lake Washington water levels are monitored by the Lake Observations by Citizen Scientists & Satellites (LOCSS) at the Juanita Beach Park in Kirkland, Washington. Data from the LOCSS website suggests that water levels fluctuate about 2 feet annually with a low water level of 16.5 feet elevation. Surface water runoff, groundwater recharge, and lake water levels likely all affect groundwater levels at the airport. Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 8 HWA GEOSCIENCES INC. 4.0 CONCLUSIONS AND RECOMMENDATIONS 4.1 GENERAL The results of the explorations and FWD testing indicate the presence of soft to very soft, fine- grained soils, including layers of peat and organic silt, that will likely require stabilization before new pavement is constructed. Site 2, near the southwest corner of Taxiway A has loose, but mostly granular, subsurface conditions. The loose soils will require thorough compaction before pavement reconstruction. 4.2 FROST CONDITIONS A frost depth penetration analysis was performed as part of the project. The alluvial soils encountered at GA Apron are considered frost susceptible and are classified as Frost Group FG-4, per the Airport Pavement Design and Evaluation Advisory Circular (FAA, 2021), based on grain size analyses. Contour maps of maximum frost penetration depth for this area indicate a depth of 12 inches for fine-grained soils (Pavement Interactive website). At the site near the southwest corner of Taxiway A, the soil is classified as Frost Group FG-2. Contour maps of maximum frost penetration depth for this area indicate a depth of about 20 inches for coarse-grained soils (Pavement Interactive Website). 4.3 DRAINAGE It is essential to the satisfactory performance of the pavement that good drainage is provided to prevent water ponding on or alongside, or accumulating beneath, the pavement. Water ponding can cause saturation of the pavement and subgrade layers and lead to premature failure. The base layers and subgrade surface should be graded to prevent water being trapped within the layer. The surface of the pavement should be sloped to convey water away from the pavement to appropriate drainage facilities. 4.4 WET WEATHER EARTHWORK The fine-grained subgrade soils encountered at the GA Apron are highly moisture sensitive and will be unworkable and pump heavily when wet, and possibly even during dry weather as these soils tend to hold moisture and dry slowly, especially with the presence of peat and organic silt. We recommend that earthwork and paving operations occur in periods of dry summer weather. Stabilization techniques may be required prior to operation of construction equipment. If earthwork is to be performed, or fill is to be placed in wet weather or under wet conditions when soil moisture content is difficult to control, the following recommendations should apply: • The on-site, native soils will not be suitable for use as structural fill or backfill. Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 9 HWA GEOSCIENCES INC. • Earthwork should be accomplished in small sections to minimize exposure to wet weather. Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of a suitable thickness of clean structural fill. The size and type of construction equipment used may have to be limited to prevent soil disturbance. • The ground surface within the construction area should be sloped and sealed with a smooth drum vibratory roller to promote rapid runoff of precipitation, to prevent surface water from flowing into excavations, and to prevent ponding of water. • No soil should be left uncompacted, so it can absorb water. Soils that become too wet for compaction should be removed and replaced with clean granular materials. • Excavation and placement of fill should be observed on a full-time basis by a person experienced in wet weather earthwork to verify that all unsuitable materials are removed, and suitable compaction and site drainage is achieved. 4.5 TEMPORARY EXCAVATIONS Any excavations deeper than 4 feet should be sloped or shored in accordance with current State of Washington Labor and Industries Safety and Health guidelines. Per these guidelines, all soils encountered are classified as Type C Soil. Temporary unsupported excavations within Type C Soil should be sloped no steeper than 1½H:1V (horizontal: vertical). Flatter side slopes could be required for excavations below the water table or where groundwater seepage is present. The contractor should monitor the stability of the temporary excavations and adjust the construction schedule and slope inclination accordingly. The contractor should be responsible for control of ground and surface water and should employ sloping, slope protection, ditching, sumps, dewatering, and other measures, as necessary, to prevent sloughing of soils and heave of the bottom of the excavation. 5.0 CONDITIONS AND LIMITATIONS We have prepared this report for DOWL Engineering for use in design of this project. This report should be provided in its entirety to prospective contractors for bidding and estimating purposes; however, the conclusions and interpretations presented herein should not be construed as a warranty of the subsurface conditions. Experience shows that soil and ground water conditions can vary significantly over small distances. Inconsistent conditions may occur between explorations that may not be detected by a geotechnical study of this nature. If, during future site operations, subsurface conditions are encountered which vary appreciably from those described herein, HWA should be notified to review the recommendations made in this report, and revise, if necessary. If there is a substantial lapse of time between submission of this report Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 November 2, 2023 HWA Project No. 2023-055-21 Renton Municipal Airport – GA Apron Rehabilitation 10 HWA GEOSCIENCES INC. and the start of construction, or if conditions change due to construction operations, it is recommended that this report be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions and time lapse. This report is issued with the understanding that it is the responsibility of the owner, or the owners’ representative, to ensure that the information and recommendations are brought to the attention of the appropriate design team personnel and incorporated into the project plans and specifications, and the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. We recommend HWA be retained to monitor construction, evaluate subgrade soil conditions as they are exposed, and verify that subgrade preparation, backfilling, and compaction are accomplished in accordance with the specifications. Within the limitations of scope, schedule and budget, HWA attempted to execute these services in accordance with generally accepted professional principles and practices in the fields of geotechnical and pavement engineering at the time the report was prepared. No warranty, express or implied, is made. The scope of our work did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous or toxic substances in the soil, surface water, or ground water at this site. ◆ We appreciate this opportunity to be of service. If you have questions or require additional services, please contact either of the undersigned below. Sincerely, HWA GEOSCIENCES INC. Seth Pemble, L.G. Bryan K. Hawkins, P.E. Geologist Senior Geotechnical Engineer Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 REFERENCES Federal Aviation Administration (FAA), 2016, Advisory Circular No. 150/5320-6G, Airport Pavement Design and Evaluation, dated 6/7/2021. Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 Project Location - Figure 2B Project Location - Figure 2A Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 BH-1 BH-3 BH-2 BH-4 Core-1 Core-5 Core-3 Core-4 Core-6 Core-2 Core-2A Legend Pavement Core Designation & Approximate LocationCore-3 Borehole Designation & Approximate LocationBH-1 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 BH-5 BH-6 BH-7 Legend Borehole Designation & Approximate LocationBH-5 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 FIGURE NO.: DRAWN BY.: CHECK BY.: PROJECT # FWD TEST RESULTS - GA APRON MAXIMUM DEFLECTIONS Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington 2023-055 RM BKH 3 City of Renton, County of King, Bureau of Land Management, Esri Canada, Esri, HERE, Garmin, INCREMENT P, USGS, EPA, USDA, King County, EagleView Technologies, Inc.0 60 120 18030 Feet ¯ Legend Maximum Deflections Deflections (Mils) 0 – 10 > 10 – 20 > 20 – 30 > 30 – 40 > 40 – 50 > 50 – 60 > 60 – 70 > 70 – 80 > 80 – 140 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 FIGURE NO.: DRAWN BY.: CHECK BY.: PROJECT # FWD TEST RESULTS - GA APRON SUBGRADE RESILIENT MODULI Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington 2023-055 RM BKH 4 Map data © OpenStreetMap contributors, Microsoft, Facebook, Inc. and its affiliates, Esri Community Maps contributors, Map layer by Esri, City of Renton, County of King, Bureau of Land Management, Esri Canada, Esri, HERE, Garmin, INCREMENT P, USGS, EPA, USDA, EagleView Technologies, Inc., Esri, USDA FSA06012018030 Feet ¯ Legend Subgrade Resilient Modulus ksi 2 – 4 > 4 – 8 > 8 – 12 > 12 – 16 > 16 – 24 > 24 – 36 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 APPENDIX A FIELD EXPLORATIONS Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 A-12023-055 Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington SYMBOLS USED ON EXPLORATION LOGS LEGEND OF TERMS AND Clean Gravel (little or no fines) More than 50% of Coarse Fraction Retained on No. 4 Sieve Gravel with SM SC ML MH CH OH RELATIVE DENSITY OR CONSISTENCY VERSUS SPT N-VALUE Very Loose Loose Medium Dense Very Dense Dense N (blows/ft) 0 to 4 4 to 10 10 to 30 30 to 50 over 50 Approximate Relative Density(%) 0 - 15 15 - 35 35 - 65 65 - 85 85 - 100 COHESIVE SOILS Consistency Very Soft Soft Medium Stiff Stiff Very Stiff Hard N (blows/ft) 0 to 2 2 to 4 4 to 8 8 to 15 15 to 30 over 30 Approximate Undrained Shear Strength (psf) <250 250 - No. 4 Sieve Sand with Fines (appreciable amount of fines) amount of fines) More than 50% Retained on No. 200 Sieve Size Sand and Sandy Soils Clean Sand (little or no fines) 50% or More of Coarse Fraction Passing Fine Grained Soils Silt and Clay Liquid Limit Less than 50% 50% or More Passing No. 200 Sieve Size Silt and Clay Liquid Limit 50% or More 500 500 - 1000 1000 - 2000 2000 - 4000 >4000 DensityDensity USCS SOIL CLASSIFICATION SYSTEM Coarse Grained Soils Gravel and Gravelly Soils Highly Organic Soils GROUP DESCRIPTIONS Well-graded GRAVEL Poorly-graded GRAVEL Silty GRAVEL Clayey GRAVEL Well-graded SAND Poorly-graded SAND Silty SAND Clayey SAND SILT Lean CLAY Organic SILT/Organic CLAY Elastic SILT Fat CLAY Organic SILT/Organic CLAY PEAT MAJOR DIVISIONS GW SP CL OL PT GP GM GC SW COHESIONLESS SOILS Fines (appreciable LEGEND 2023-055.GPJ 8/29/23 PROJECT NO.:FIGURE: Coarse sand Medium sand SIZE RANGE Larger than 12 in Smaller than No. 200 (0.074mm) Gravel 3 in to 12 in 3 in to No 4 (4.5mm) No. 4 (4.5 mm) to No. 200 (0.074 mm) COMPONENT DRY Absence of moisture, dusty, dry to the touch. MOIST COMPONENT DEFINITIONS time of drilling) Groundwater Level (measured in well or open hole after water level stabilized) Groundwater Level (measured at TEST SYMBOLS GROUNDWATER SYMBOLS AL Atterberg Limits: California Bearing Ratio CN Consolidation DD OC Organic Content pH pH of Soils 12 - 30% Clayey, Silty, Sandy, Gravelly 3 in to 3/4 in 3/4 in to No 4 (4.5mm) No. 4 (4.5 mm) to No. 10 (2.0 mm) No. 10 (2.0 mm) to No. 40 (0.42 mm) No. 40 (0.42 mm) to No. 200 (0.074 mm) NOTES: Soil classifications presented on exploration logs are based on visual and laboratory observation. Density/consistency, color, modifier (if any) GROUP NAME, additions to group name (if any), moisture content. Proportion, gradation, and angularity of constituents, additional comments. (GEOLOGIC INTERPRETATION) Please refer to the discussion in the report text as well as the exploration logs for a more complete description of subsurface conditions. Soil descriptions are presented in the following general order: < 5% Damp but no visible water. WET Visible free water, usually soil is below water table. Boulders Cobbles Coarse gravel Fine gravel Sand MOISTURE CONTENT COMPONENT PROPORTIONS Fine sand Silt and Clay 5 - 12% PROPORTION RANGE DESCRIPTIVE TERMS Clean Slightly (Clayey, Silty, Sandy) 30 - 50% Components are arranged in order of increasing quantities. Very (Clayey, Silty, Sandy, Gravelly) PID PP CBR DS Direct Shear GS Grain Size Distribution K Permeability Moisture/Density Relationship (Proctor) Resilient Modulus Photoionization Device Reading Res. Resistivity SG Percent Fines%F MD MR Specific Gravity CD Consolidated Drained Triaxial Torvane (Approx. Shear Strength, tsf) Dry Density (pcf) CU Consolidated Undrained Triaxial TV UU Unconsolidated Undrained Triaxial UC Unconfined Compression SAMPLE TYPE SYMBOLS Non-standard Penetration Test(3.0" OD Split Spoon with Brass Rings) (140 lb. hammer with 30 in. drop) Shelby Tube Small Bag Sample Large Bag (Bulk) Sample Core Run 2.0" OD Split Spoon (SPT) PL = Plastic Limit, LL = Liquid Limit Pocket Penetrometer (Approx. Comp. Strength, tsf) 3-1/4" OD Split Spoon Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GW SP SMML 3 inches Hot Mix Asphalt.1 lift.Cored on medium severity sealed longitudinal crack. Crack filled with organics below sealant. 4 inches Crushed Surfacing Base Course. Dense, brown, sandy, coarse, crushed GRAVEL with silt,moist. (CSBC) 6 inches Gravel Borrow. Medium dense, brown, sandy, fine to coarse, roundedGRAVEL, moist. (GRAVEL BORROW) Loose, brown, fine to medium SAND, moist. Very loose, dark gray, very silty SAND to sandy SILT, wet. Corehole was terminated at 60 inches below groundsurface. Groundwater seepage was observed at 54 inches below ground surface. S-1 LOGGED BY: B. Hawkins and therefore may not necessarily be indicative of other times and/or locations. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTIONSY M B O L PAGE: 1 of 1 Core-1 EXCAVATING EQUIPMENT: 6-inch Diameter Core Barrel PROJECT NO.: MO I S T U R E CO N T E N T ( % ) Geotechnical Services STREET: PAVEMENT CORE EXCAVATION COMPANY: HWA GeoSciences Inc. SA M P L E N U M B E R SA M P L E T Y P E OT H E R T E S T S DATE COMPLETED: 8/21/23 FIGURE: US C S S O I L C L A S S . 2023-055 PAVEMENT CORE PHOTO 2023-055.GPJ 11/2/23 Renton Municipal Airport GA Apron Rehabilitation Renton, Washington A-2 DE P T H ( f e e t ) PAVEMENT CORE PHOTO GA Apron LOCATION: See Figure 2A 0 1 2 3 4 5 6 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 2.75 inches Hot Mix Asphalt.No cracking at core location. (HMA) 4.25 inches Crushed Surfacing Base Course. Dense, brownish gray, sandy, coarse, crushed GRAVELwith silt, moist. (CSBC) Corehole was terminated at 7 inches below groundsurface due to encountering a vertical steel plate embedded in PCC below the CSBC. Core-2A was drilled 4feet South and 1.5 feet east of Core-2. LOGGED BY: B. Hawkins and therefore may not necessarily be indicative of other times and/or locations. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTIONSY M B O L PAGE: 1 of 1 Core-2 EXCAVATING EQUIPMENT: 6-inch Diameter Core Barrel PROJECT NO.: MO I S T U R E CO N T E N T ( % ) Geotechnical Services STREET: PAVEMENT CORE EXCAVATION COMPANY: HWA GeoSciences Inc. SA M P L E N U M B E R SA M P L E T Y P E OT H E R T E S T S DATE COMPLETED: 8/21/23 FIGURE: US C S S O I L C L A S S . 2023-055 PAVEMENT CORE PHOTO 2023-055.GPJ 11/2/23 Renton Municipal Airport GA Apron Rehabilitation Renton, Washington A-3 DE P T H ( f e e t ) PAVEMENT CORE PHOTO GA Apron LOCATION: See Figure 2A 0 1 2 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 2.5 inches Hot Mix Asphalt.1 lift.No cracking in this location. 4 inches Crushed Surfacing Base Course. Dense, brownish gray, sandy, coarse, crushed GRAVELwith silt, moist. (CSBC) 4 inches Portland Cement Concrete.Cored with 4-inch diameter barrel. (PCC) Dense, gray, sandy, coarse, crushed GRAVEL with silt,moist. (CSBC) Corehole was terminated at 13 inches below groundsurface. No groundwater seepage was observed during the exploration. S-1 LOGGED BY: B. Hawkins and therefore may not necessarily be indicative of other times and/or locations. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTIONSY M B O L PAGE: 1 of 1 Core-2A EXCAVATING EQUIPMENT: 6-inch Diameter Core Barrel PROJECT NO.: MO I S T U R E CO N T E N T ( % ) Geotechnical Services STREET: PAVEMENT CORE EXCAVATION COMPANY: HWA GeoSciences Inc. SA M P L E N U M B E R SA M P L E T Y P E OT H E R T E S T S DATE COMPLETED: 8/21/23 FIGURE: US C S S O I L C L A S S . 2023-055 PAVEMENT CORE PHOTO 2023-055.GPJ 11/2/23 Renton Municipal Airport GA Apron Rehabilitation Renton, Washington A-4 DE P T H ( f e e t ) PAVEMENT CORE PHOTO GA Apron LOCATION: See Figure 2A 0 1 2 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GW ML ML MLPT ML SPSM 2.25 inches Hot Mix Asphalt.1 lift.Cored on medium to high severity alligator cracking. Core cracked through full depth and broken into 3 pieces. (HMA) 4.25 inches Crushed Surfacing Base Course.Dense, brown, sandy, coarse, crushed GRAVEL with silt, moist. (CSBC) 5 inches Gravel Borrow.Medium dense, dark gray, silty, sandy, fine to coarse,rounded GRAVEL, moist. (GRAVEL BORROW) Medium stiff, dark gray SILT with sand, moist. Medium stiff, dark brown SILT with organics, moist. Soft, dark brown SILT with peat lenses, moist. Soft, dark gray, clayey silt to silty clay, moist. Loose, dark gray, clean, fine to medium SAND with lensesof silty, fine SAND, wet. Corehole was terminated at 51 inches below ground surface. Groundwater seepage was observed at 47 inchesbelow ground surface. S-1 S-2 LOGGED BY: B. Hawkins and therefore may not necessarily be indicative of other times and/or locations. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTIONSY M B O L PAGE: 1 of 1 Core-3 EXCAVATING EQUIPMENT: 6-inch Diameter Core Barrel PROJECT NO.: MO I S T U R E CO N T E N T ( % ) Geotechnical Services STREET: PAVEMENT CORE EXCAVATION COMPANY: HWA GeoSciences Inc. SA M P L E N U M B E R SA M P L E T Y P E OT H E R T E S T S DATE COMPLETED: 8/21/23 FIGURE: US C S S O I L C L A S S . 2023-055 PAVEMENT CORE PHOTO 2023-055.GPJ 11/2/23 Renton Municipal Airport GA Apron Rehabilitation Renton, Washington A-5 DE P T H ( f e e t ) PAVEMENT CORE PHOTO GA Apron LOCATION: See Figure 2A 0 1 2 3 4 5 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 ML ML SP SPSM 2 inches Hot Mix Asphalt.1 lift.Cored on medium to high severity alligator cracking. Cracked through full depth. (HMA) 2 inches Crushed Surfacing Base Course.Dense, brown, sandy, coarse, crushed GRAVEL with silt, moist. (CSBC) Medium stiff, dark gray SILT with sand and occassionalfine to coarse gravel, moist.4-inch cobble at 5 to 9-inches below ground surface. Medium stiff to soft, dark gray SILT with fine sand, moist. Loose, dark gray, fine to medium SAND, moist. Loose, dark gray, fine to medium SAND with silt, moist. Corehole was terminated at 36 inches below groundsurface. No groundwater seepage was observed duringthe exploration. S-1 S-2 S-3 LOGGED BY: B. Hawkins and therefore may not necessarily be indicative of other times and/or locations. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTIONSY M B O L PAGE: 1 of 1 Core-4 EXCAVATING EQUIPMENT: 6-inch Diameter Core Barrel PROJECT NO.: MO I S T U R E CO N T E N T ( % ) Geotechnical Services STREET: PAVEMENT CORE EXCAVATION COMPANY: HWA GeoSciences Inc. SA M P L E N U M B E R SA M P L E T Y P E OT H E R T E S T S DATE COMPLETED: 8/21/23 FIGURE: US C S S O I L C L A S S . 2023-055 PAVEMENT CORE PHOTO 2023-055.GPJ 11/2/23 Renton Municipal Airport GA Apron Rehabilitation Renton, Washington A-6 DE P T H ( f e e t ) PAVEMENT CORE PHOTO GA Apron LOCATION: See Figure 2A 0 1 2 3 4 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GW GP 2 inches Hot Mix Asphalt.1 lift.Cored on sealed, medium severity longitudinal crack. Core cracked through full depth with sealant holding core together and vegetation in crack below sealant. (HMA) 1 inch Crushed Surfacing Base Course. Medium dense, brown, sandy, coarse, mostly crushed with some rounded GRAVEL with silt, moist. (CSBC) 7 inches Gravel Borrow.Medium dense, brown, sandy, fine to coarse, rounded GRAVEL, moist. (GRAVEL BORROW) 3.25 inches Asphaltic Material.Cored using 4-inch diameter core barrel. Very soft. Crumbles easily. High oil content. (OLD ASPHALT LAYER) 0.75 inches Cement.Gray cement with silt. Dense, dark gray GRAVEL with silth and sand, moist. Corehole was terminated at 16 inches below groundsurface. No groundwater seepage was observed duringthe exploration. LOGGED BY: B. Hawkins and therefore may not necessarily be indicative of other times and/or locations. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTIONSY M B O L PAGE: 1 of 1 Core-5 EXCAVATING EQUIPMENT: 6-inch Diameter Core Barrel PROJECT NO.: MO I S T U R E CO N T E N T ( % ) Geotechnical Services STREET: PAVEMENT CORE EXCAVATION COMPANY: HWA GeoSciences Inc. SA M P L E N U M B E R SA M P L E T Y P E OT H E R T E S T S DATE COMPLETED: 8/21/23 FIGURE: US C S S O I L C L A S S . 2023-055 PAVEMENT CORE PHOTO 2023-055.GPJ 11/2/23 Renton Municipal Airport GA Apron Rehabilitation Renton, Washington A-7 DE P T H ( f e e t ) PAVEMENT CORE PHOTO GA Apron LOCATION: See Figure 2A 0 1 2 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GP 2.25 inches Hot Mix Asphalt.1 Lift.Cored on medium severity sealed crack. Cracked through full depth. Sealant holding pieces together with silt and organics in joint below sealant. (HMA) 5.25 inches Crushed Surfacing Base Course. Dense, grayish brown, sandy, crushed, coarse GRAVEL with silt, moist. (CSBC) Dense, brown, sandy, fine to coarse GRAVEL with silt,moist. (FILL) Becomes dark gray at 17 inches below ground surface. Corehole was terminated at 20 inches below ground surface. No groundwater seepage was observed duringthe exploration. S-1 LOGGED BY: B. Hawkins and therefore may not necessarily be indicative of other times and/or locations. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTIONSY M B O L PAGE: 1 of 1 Core-6 EXCAVATING EQUIPMENT: 6-inch Diameter Core Barrel PROJECT NO.: MO I S T U R E CO N T E N T ( % ) Geotechnical Services STREET: PAVEMENT CORE EXCAVATION COMPANY: HWA GeoSciences Inc. SA M P L E N U M B E R SA M P L E T Y P E OT H E R T E S T S DATE COMPLETED: 8/21/23 FIGURE: US C S S O I L C L A S S . 2023-055 PAVEMENT CORE PHOTO 2023-055.GPJ 11/2/23 Renton Municipal Airport GA Apron Rehabilitation Renton, Washington A-8 DE P T H ( f e e t ) PAVEMENT CORE PHOTO GA Apron LOCATION: See Figure 2A 0 1 2 3 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GS GS AL OC S-1 S-2A S-2B S-3 S-4 S-5 2.75 inches Hot Mix Asphalt. (HMA) Very loose, brown, sandy GRAVEL with silt, moist. (GRAVEL BORROW FILL) Soft, gray, SILT with sand, moist. (ALLUVIUM) Very loose, gray, poorly graded SAND with silt, moist. Very loose, gray, poorly graded SAND with silt, moist to wet. Very soft, dark grayish brown, organic SILT with thin sand lenses, moist. Decomposing wood in tip of sampler. Becomes brown with fine peaty organics, moist. Organic content = 16.4% Borehole was terminated at 11.5 feet below ground surface. Groundwater seepage was observed at 6 feet below ground surface. 2-1-2 1-2-2 1-2-2 0/18" 0/18" GP GM ML SP SM SP SM OH BORING-DSM 2023-055.GPJ 11/2/23 FIGURE:PROJECT NO.:2023-055 Renton, Washington Geotechnical Services Renton Municipal Airport GA Apron Rehabilitation Natural Water Content US C S S O I L C L A S S Water Content (%) NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTION BH-1 PAGE: 1 of 1 (b l o w s / 6 i n c h e s ) GR O U N D W A T E R PE N . R E S I S T A N C E Liquid Limit SY M B O L 0 10 20 30 40 50 0 20 40 60 80 100 SA M P L E T Y P E SA M P L E N U M B E R OT H E R T E S T S Plastic Limit BORING: and therefore may not necessarily be indicative of other times and/or locations. (140 lb. weight, 30" drop) Blows per foot Standard Penetration Test A-9 DE P T H (f e e t ) 0 5 10 15 EL E V A T I O N (f e e t ) DATE COMPLETED: 8/28/2023 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: HSA w/Mobile B-58 Truck Rig LOCATION: See Figure 2A DATE STARTED: 8/28/2023 SAMPLING METHOD: SPT w/Autohammer LOGGED BY: S. Pemble >>>>243 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 AL AL S-1 S-2 S-3 S-4A S-4B S-5 3.25 inches Hot Mix Asphalt. (HMA) 4.25 inches Portland Cement Concrete. (PCC) Very soft, dark grayish brown, SILT with fine organics, moist. (ALLUVIUM) Very soft, dark grayish brown and gray, organic SILT with fine peaty organics, moist. Very soft, gray, interlayered, fine sandy SILT and silty, fine SAND, moist to wet. Very loose, gray, silty, fine SAND with scattered fine organics, moist to wet. Very soft, dark grayish brown, fine, sandy SILT with scattered fine organics, moist. Becomes brown with peaty organics, moist. Borehole was terminated at 11.5 feet below ground surface. Slow groundwater seepage was observed at 5 feet below ground surface. 0/18" 0/18" 0/18" 0/18" 0/18" OH OH ML SM ML BORING-DSM 2023-055.GPJ 11/2/23 FIGURE:PROJECT NO.:2023-055 Renton, Washington Geotechnical Services Renton Municipal Airport GA Apron Rehabilitation Natural Water Content US C S S O I L C L A S S Water Content (%) NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTION BH-2 PAGE: 1 of 1 (b l o w s / 6 i n c h e s ) GR O U N D W A T E R PE N . R E S I S T A N C E Liquid Limit SY M B O L 0 10 20 30 40 50 0 20 40 60 80 100 SA M P L E T Y P E SA M P L E N U M B E R OT H E R T E S T S Plastic Limit BORING: and therefore may not necessarily be indicative of other times and/or locations. (140 lb. weight, 30" drop) Blows per foot Standard Penetration Test A-10 DE P T H (f e e t ) 0 5 10 15 EL E V A T I O N (f e e t ) DATE COMPLETED: 8/28/2023 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: HSA w/Mobile B-58 Truck Rig LOCATION: See Figure 2A DATE STARTED: 8/28/2023 SAMPLING METHOD: SPT w/Autohammer LOGGED BY: S. Pemble >> >>195 Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 AL GS S-1 S-2A S-2B S-3 S-4 S-5 2.5 inches Hot Mix Asphalt. (HMA) Loose, brown and gray, sandy GRAVEL with silt, moist. (FILL) Very soft, greenish gray, SILT, moist. (ALLUVIUM) Very soft, dark gray, SILT, moist. Very loose, gray, SAND with silt and fine silty SAND laminations, wet. Very soft, dark grayish brown, fine sandy SILT with charcoal and interlayered organic SILT, moist. Very soft, dark grayish brown, organic SILT with scattered fine peaty organics, moist. Borehole was terminated at 11.5 feet below ground surface. Groundwater seepage was observed at 5 feet below ground surface. 6-3-2 1-0-1 1-2-1 0/18" 0/18" GP GM ML ML SP SM ML OL BORING-DSM 2023-055.GPJ 11/2/23 FIGURE:PROJECT NO.:2023-055 Renton, Washington Geotechnical Services Renton Municipal Airport GA Apron Rehabilitation Natural Water Content US C S S O I L C L A S S Water Content (%) NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTION BH-3 PAGE: 1 of 1 (b l o w s / 6 i n c h e s ) GR O U N D W A T E R PE N . R E S I S T A N C E Liquid Limit SY M B O L 0 10 20 30 40 50 0 20 40 60 80 100 SA M P L E T Y P E SA M P L E N U M B E R OT H E R T E S T S Plastic Limit BORING: and therefore may not necessarily be indicative of other times and/or locations. (140 lb. weight, 30" drop) Blows per foot Standard Penetration Test A-11 DE P T H (f e e t ) 0 5 10 15 EL E V A T I O N (f e e t ) DATE COMPLETED: 8/28/2023 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: HSA w/Mobile B-58 Truck Rig LOCATION: See Figure 2A DATE STARTED: 8/28/2023 SAMPLING METHOD: SPT w/Autohammer LOGGED BY: S. Pemble Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GS GS S-1 S-2 S-3 S-4 S-5 2.5 inches Hot Mix Asphalt. (HMA) Loose, brown, silty SAND with gravel, moist. (FILL) Very loose, dark gray, silty SAND with gravel and a small white shell fragment, moist. (ALLUVIUM) Very loose, gray, poorly graded SAND with silt and 2 inch thick interlayered silty fine SAND, wet. Very soft, gray, fine sandy SILT with scattered fine organics, wet. Very soft, dark grayish brown, fine sandy SILT with fine organics and thin interlayered silty SAND, wet. Organic silt in tip of sampler. Borehole was terminated at 11.5 feet below ground surface. Groundwater seepage was observed at 5.5 feet below ground surface. 5-3-2 1-1-2 1-1-1 0-0-1 0/18" SM SM SP SM ML ML BORING-DSM 2023-055.GPJ 11/2/23 FIGURE:PROJECT NO.:2023-055 Renton, Washington Geotechnical Services Renton Municipal Airport GA Apron Rehabilitation Natural Water Content US C S S O I L C L A S S Water Content (%) NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTION BH-4 PAGE: 1 of 1 (b l o w s / 6 i n c h e s ) GR O U N D W A T E R PE N . R E S I S T A N C E Liquid Limit SY M B O L 0 10 20 30 40 50 0 20 40 60 80 100 SA M P L E T Y P E SA M P L E N U M B E R OT H E R T E S T S Plastic Limit BORING: and therefore may not necessarily be indicative of other times and/or locations. (140 lb. weight, 30" drop) Blows per foot Standard Penetration Test A-12 DE P T H (f e e t ) 0 5 10 15 EL E V A T I O N (f e e t ) DATE COMPLETED: 8/28/2023 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: HSA w/Mobile B-58 Truck Rig LOCATION: See Figure 2A DATE STARTED: 8/28/2023 SAMPLING METHOD: SPT w/Autohammer LOGGED BY: S. Pemble Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GS GS S-1 S-2 S-3 S-4 S-5 6 inches Portland Cement Concrete. (PCC) Loose, brown, poorly graded SAND with gravel, moist. (REWORKED/REGRADED ALLUVIUM) Loose, gray, silty SAND with gravel and scattered organics, moist. Becomes very loose with fine gravel, moist. Very loose, gray, silty SAND with scattered fine gravel, wet. Interlayered SAND with silt and fine organics. (ALLUVIUM) Becomes loose, gray, gravelly, silty SAND, wet. Borehole was terminated at 11.5 feet below ground surface. Groundwater seepage was observed at 8 feet below ground surface. 3-4-2 3-4-2 1-1-1 0-1-1 1-3-2 SP SM SM BORING-DSM 2023-055.GPJ 11/2/23 FIGURE:PROJECT NO.:2023-055 Renton, Washington Geotechnical Services Renton Municipal Airport GA Apron Rehabilitation Natural Water Content US C S S O I L C L A S S Water Content (%) NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTION BH-5 PAGE: 1 of 1 (b l o w s / 6 i n c h e s ) GR O U N D W A T E R PE N . R E S I S T A N C E Liquid Limit SY M B O L 0 10 20 30 40 50 0 20 40 60 80 100 SA M P L E T Y P E SA M P L E N U M B E R OT H E R T E S T S Plastic Limit BORING: and therefore may not necessarily be indicative of other times and/or locations. (140 lb. weight, 30" drop) Blows per foot Standard Penetration Test A-13 DE P T H (f e e t ) 0 5 10 15 EL E V A T I O N (f e e t ) DATE COMPLETED: 8/28/2023 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: HSA w/Mobile B-58 Truck Rig LOCATION: See Figure 2B DATE STARTED: 8/28/2023 SAMPLING METHOD: SPT w/Autohammer LOGGED BY: S. Pemble Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GS GS S-1 S-2 S-3 S-4 S-5 1.5 inches Hot Mix Asphalt. (HMA) Loose, brown, gravelly, SAND with silt, moist. (FILL) Loose, brown and gray mottled, gravelly, silty SAND, moist. Loose, gray, interlayered, poorly graded SAND and silty SAND with gravel, moist. (REWORKED/REGRADED ALLUVIUM) Loose, gray, sandy, poorly graded GRAVEL, moist. Loose, gray, sandy, fine GRAVEL, moist. Poor recovery. Loose, gray, sandy, poorly graded GRAVEL with silt, wet. Poor recovery. (ALLUVIUM) Borehole was terminated at 11.5 feet below ground surface. Groundwater seepage was observed at 10 feet below ground surface. 7-3-3 1-2-7 2-3-5 3-4-3 3-3-4 SP SM SM SP SM GP GP GP GM BORING-DSM 2023-055.GPJ 11/2/23 FIGURE:PROJECT NO.:2023-055 Renton, Washington Geotechnical Services Renton Municipal Airport GA Apron Rehabilitation Natural Water Content US C S S O I L C L A S S Water Content (%) NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTION BH-6 PAGE: 1 of 1 (b l o w s / 6 i n c h e s ) GR O U N D W A T E R PE N . R E S I S T A N C E Liquid Limit SY M B O L 0 10 20 30 40 50 0 20 40 60 80 100 SA M P L E T Y P E SA M P L E N U M B E R OT H E R T E S T S Plastic Limit BORING: and therefore may not necessarily be indicative of other times and/or locations. (140 lb. weight, 30" drop) Blows per foot Standard Penetration Test A-14 DE P T H (f e e t ) 0 5 10 15 EL E V A T I O N (f e e t ) DATE COMPLETED: 8/28/2023 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: HSA w/Mobile B-58 Truck Rig LOCATION: See Figure 2B DATE STARTED: 8/28/2023 SAMPLING METHOD: SPT w/Autohammer LOGGED BY: S. Pemble Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 GS GS S-1 S-2 S-3 S-4 S-5 1.5 inches Hot Mix Asphalt. (HMA) Loose, brown, silty, sandy, poorly graded GRAVEL, moist. (FILL) Loose, gray, silty SAND with scattered gravel, moist. (REWORKED/REGRADED ALLUVIUM) With scattered fine gravel, dark brown organics and wood, moist. Loose, gray, silty SAND with scattered fine gravel and medium SAND interlayers, moist. (ALLUVIUM) Loose, gray, sandy, poorly graded GRAVEL, moist. Loose, dark gray, poorly graded SAND with silt and gravel, wet. Drove rock, poor recovery. Borehole was terminated at 11.5 feet below ground surface. Groundwater seepage was observed at 10 feet below ground surface. 4-3-4 2-2-2 1-2-4 5-3-3 1-2-3 GM SM SM GP SP SM BORING-DSM 2023-055.GPJ 11/2/23 FIGURE:PROJECT NO.:2023-055 Renton, Washington Geotechnical Services Renton Municipal Airport GA Apron Rehabilitation Natural Water Content US C S S O I L C L A S S Water Content (%) NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated DESCRIPTION BH-7 PAGE: 1 of 1 (b l o w s / 6 i n c h e s ) GR O U N D W A T E R PE N . R E S I S T A N C E Liquid Limit SY M B O L 0 10 20 30 40 50 0 20 40 60 80 100 SA M P L E T Y P E SA M P L E N U M B E R OT H E R T E S T S Plastic Limit BORING: and therefore may not necessarily be indicative of other times and/or locations. (140 lb. weight, 30" drop) Blows per foot Standard Penetration Test A-15 DE P T H (f e e t ) 0 5 10 15 EL E V A T I O N (f e e t ) DATE COMPLETED: 8/28/2023 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: HSA w/Mobile B-58 Truck Rig LOCATION: See Figure 2B DATE STARTED: 8/28/2023 SAMPLING METHOD: SPT w/Autohammer LOGGED BY: S. Pemble Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 APPENDIX B LABORATORY TEST RESULTS Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 BH-1,S-2A 2.5 3.0 29.5 1.2 14.6 84.2 ML Very dark gray, SILT with sand BH-1,S-2B 3.0 4.0 11.2 0.1 90.2 9.7 SP-SM Very dark gray, poorly graded SAND with silt BH-1,S-5 10.0 11.5 242.8 16.4 246 183 63 OH Very dark brown, organic SILT BH-2,S-1 1.0 2.5 92.9 121 78 43 OH Very dark gray, organic SILT BH-2,S-2 2.5 4.0 195.2 117 84 33 OH Dark grayish-brown, organic SILT BH-3,S-2B 3.5 4.0 39.5 39 30 9 ML Very dark gray, SILT BH-3,S-3 5.0 6.5 26.9 93.2 6.8 SP-SM Very dark gray, poorly graded SAND with silt BH-4,S-1 0.4 1.9 7.6 35.2 50.8 14.0 SM Very dark grayish-brown, silty SAND with gravel BH-4,S-3 5.0 6.5 29.9 0.4 79.2 20.4 SM Very dark gray, silty SAND BH-5,S-1 0.5 2.0 4.1 40.0 55.6 4.4 SP Dark yellowish-brown, poorly graded SAND with gravel BH-5,S-2 2.5 4.0 8.7 40.0 42.3 17.7 SM Very dark gray, silty SAND with gravel BH-6,S-2 2.5 4.0 9.2 34.2 43.6 22.2 SM Very dark gray, silty SAND with gravel BH-6,S-3 5.0 6.5 2.4 58.2 38.4 3.4 GP Very dark gray, poorly graded GRAVEL with sand BH-7,S-2 2.5 4.0 12.5 6.6 51.9 41.4 SM Very dark gray, silty SAND BH-7,S-4 7.5 9.0 3.1 53.2 43.2 3.6 GP Very dark gray, poorly graded GRAVEL with sand (f e e t ) TO P D E P T H SAMPLE DESCRIPTION Notes: AS T M S O I L MO I S T U R E CO N T E N T ( % ) OR G A N I C % F I N E S SP E C I F I C G R A V I T Y EX P L O R A T I O N DE S I G N A T I O N 1. This table summarizes information presented elsewhere in the report and should be used in conjunction with the report test, other graphs and tables, and the exploration logs. 2. The soil classifications in this table are based on ASTM D2487 and D2488 as applicable. MATERIAL PROPERTIES B-1 PAGE: 1 of 1 SUMMARY OF LIMITS (%) ATTERBERG BO T T O M D E P T H CO N T E N T ( % ) % S A N D % G R A V E L PIPLLL CL A S S I F I C A T I O N (f e e t ) 2023-055PROJECT NO.: INDEX MATSUM 2 2023-055.GPJ 9/7/23 FIGURE: Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.1110 GRAIN SIZE IN MILLIMETERS 50 SAMPLE S-2A S-2B S-3 2.5 - 3.0 3.0 - 4.0 5.0 - 6.5 #10 14.6 90.2 93.2 30 CLASSIFICATION OF SOIL- ASTM D2487 Group Symbol and Name U.S. STANDARD SIEVE SIZES SAND B-2 Coarse #60#40#20 Fine Coarse SYMBOL Gravel% 3"1-1/2" PE R C E N T F I N E R B Y W E I G H T #4 #200 1.2 0.1 Sand% (ML) Very dark gray, SILT with sand (SP-SM) Very dark gray, poorly graded SAND with silt (SP-SM) Very dark gray, poorly graded SAND with silt Fines% 0.00050.005 CLAY BH-1 BH-1 BH-3 SILT 3/4" GRAVEL 0.05 5/8" 70 #100 0.5 30 11 27 50 Medium Fine 3/8" 5 PI 90 10 % MC LL PLDEPTH ( ft.) PARTICLE-SIZE ANALYSIS OF SOILS METHOD ASTM D6913 84.2 9.7 6.8 2023-055PROJECT NO.: HWAGRSZ 2023-055.GPJ 9/7/23 FIGURE: Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.1110 GRAIN SIZE IN MILLIMETERS 50 SAMPLE S-1 S-3 S-1 0.4 - 1.9 5.0 - 6.5 0.5 - 2.0 #10 50.8 79.2 55.6 30 CLASSIFICATION OF SOIL- ASTM D2487 Group Symbol and Name U.S. STANDARD SIEVE SIZES SAND B-3 Coarse #60#40#20 Fine Coarse SYMBOL Gravel% 3"1-1/2" PE R C E N T F I N E R B Y W E I G H T #4 #200 35.2 0.4 40.0 Sand% (SM) Very dark grayish-brown, silty SAND with gravel (SM) Very dark gray, silty SAND (SP) Dark yellowish-brown, poorly graded SAND with gravel Fines% 0.00050.005 CLAY BH-4 BH-4 BH-5 SILT 3/4" GRAVEL 0.05 5/8" 70 #100 0.5 8 30 4 50 Medium Fine 3/8" 5 PI 90 10 % MC LL PLDEPTH ( ft.) PARTICLE-SIZE ANALYSIS OF SOILS METHOD ASTM D6913 14.0 20.4 4.4 2023-055PROJECT NO.: HWAGRSZ 2023-055.GPJ 9/7/23 FIGURE: Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.1110 GRAIN SIZE IN MILLIMETERS 50 SAMPLE S-2 S-2 S-3 2.5 - 4.0 2.5 - 4.0 5.0 - 6.5 #10 42.3 43.6 38.4 30 CLASSIFICATION OF SOIL- ASTM D2487 Group Symbol and Name U.S. STANDARD SIEVE SIZES SAND B-4 Coarse #60#40#20 Fine Coarse SYMBOL Gravel% 3"1-1/2" PE R C E N T F I N E R B Y W E I G H T #4 #200 40.0 34.2 58.2 Sand% (SM) Very dark gray, silty SAND with gravel (SM) Very dark gray, silty SAND with gravel (GP) Very dark gray, poorly graded GRAVEL with sand Fines% 0.00050.005 CLAY BH-5 BH-6 BH-6 SILT 3/4" GRAVEL 0.05 5/8" 70 #100 0.5 9 9 2 50 Medium Fine 3/8" 5 PI 90 10 % MC LL PLDEPTH ( ft.) PARTICLE-SIZE ANALYSIS OF SOILS METHOD ASTM D6913 17.7 22.2 3.4 2023-055PROJECT NO.: HWAGRSZ 2023-055.GPJ 9/7/23 FIGURE: Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.1110 GRAIN SIZE IN MILLIMETERS 50 SAMPLE S-2 S-4 2.5 - 4.0 7.5 - 9.0 #10 51.9 43.2 30 CLASSIFICATION OF SOIL- ASTM D2487 Group Symbol and Name U.S. STANDARD SIEVE SIZES SAND B-5 Coarse #60#40#20 Fine Coarse SYMBOL Gravel% 3"1-1/2" PE R C E N T F I N E R B Y W E I G H T #4 #200 6.6 53.2 Sand% (SM) Very dark gray, silty SAND (GP) Very dark gray, poorly graded GRAVEL with sand Fines% 0.00050.005 CLAY BH-7 BH-7 SILT 3/4" GRAVEL 0.05 5/8" 70 #100 0.5 12 3 50 Medium Fine 3/8" 5 PI 90 10 % MC LL PLDEPTH ( ft.) PARTICLE-SIZE ANALYSIS OF SOILS METHOD ASTM D6913 41.4 3.6 2023-055PROJECT NO.: HWAGRSZ 2023-055.GPJ 9/7/23 FIGURE: Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7 0 10 20 30 40 50 60 70 80 90 100 0 40 80 120 160 200 240 10.0 - 11.5 1.0 - 2.5 2.5 - 4.0 3.5 - 4.0 (OH) Very dark brown, organic SILT (OH) Very dark gray, organic SILT (OH) Dark grayish-brown, organic SILT (ML)Very dark gray, SILT LIQUID LIMIT (LL) 246 121 117 39 % MC LL BH-1 BH-2 BH-2 BH-3 243 93 195 40 LIQUID LIMIT, PLASTIC LIMIT AND PLASTICITY INDEX OF SOILS METHOD ASTM D4318 B-6 63 43 33 9 CL-ML % FinesSAMPLE ML CLASSIFICATION MH PL A S T I C I T Y I N D E X ( P I ) SYMBOL PL PI 183 78 84 30 S-5 S-1 S-2 S-2B DEPTH (ft) CL CH 2023-055PROJECT NO.: HWAATTB EXPANDED SAMPLE COLUMN (HIGH LL) 2023-055.GPJ 9/7/23 FIGURE: Renton Municipal Airport GA Apron Rehabilitation Geotechnical Services Renton, Washington Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7