Geotechnical Engineering Report 12 10 2024 submission

REFERENCE NOTES FOR BORING LOGS MATERIAL1,2 DRILLING SAMPLING SYMBOLS & ABBREVIATIONS SS Split Spoon Sampler PM Pressuremeter Test ASPHALT ST Shelby Tube Sampler RD Rock Bit Drilling WS Wash Sample RC Rock Core, NX, BX, AX CONCRETE BS Bulk Sample of Cuttings REC Rock Sample Recovery % PA Power Auger (no sample) RQD Rock Quality Designation % GRAVEL HSA Hollow Stem Auger TOPSOIL PARTICLE SIZE IDENTIFICATION DESIGNATION PARTICLE SIZES VOID Boulders 12 inches (300 mm) or larger BRICK Cobbles 3 inches to 12 inches (75 mm to 300 mm) Gravel: Coarse ¾ inch to 3 inches (19 mm to 75 mm) AGGREGATE BASE COURSE Fine 4.75 mm to 19 mm (No. 4 sieve to ¾ inch) Sand: Coarse 2.00 mm to 4.75 mm (No. 10 to No. 4 sieve) GW WELL-GRADED GRAVEL Medium

2.00 mm to 4.75 mm (No. 10 to No. 4 sieve) GW WELL-GRADED GRAVEL Medium 0.425 mm to 2.00 mm (No. 40 to No. 10 sieve) gravel-sand mixtures, little or no fines Fine 0.074 mm to 0.425 mm (No. 200 to No. 40 sieve) GP POORLY-GRADED GRAVEL Silt & Clay (“Fines”) <0.074 mm (smaller than a No. 200 sieve) gravel-sand mixtures, little or no fines GM SILTY GRAVEL gravel-sand-silt mixtures COHESIVE SILTS & CLAYS COARSE FINE RELATIVE GRAINED GRAINED GC CLAYEY GRAVEL UNCONFINED AMOUNT7 (%)8 (%)8 gravel-sand-clay mixtures COMPRESSIVE SPT5 CONSISTENCY7 4 SW WELL-GRADED SAND STRENGTH, QP (BPF) (COHESIVE) Trace <5 <5 gravelly sand, little or no fines <0.25 <2 Very Soft SP POORLY-GRADED SAND 2-4 Soft With 10 - 20 10 - 25 0.25 - <0.50

2-4 Soft With 10 - 20 10 - 25 0.25 - <0.50 gravelly sand, little or no fines 0.50 - <1.00 5-8 Firm Adjective 25 - 45 30 - 45 SM SILTY SAND (ex: “Silty”) 1.00 - <2.00 9 - 15 Stiff sand-silt mixtures 2.00 - <4.00 16 - 30 Very Stiff SC CLAYEY SAND 4.00 - 8.00 31 - 50 Hard sand-clay mixtures >8.00 >50 Very Hard WATER LEVELS6 ML SILT non-plastic to medium plasticity GRAVELS, SANDS & NON-COHESIVE SILTS WL (First Encountered) MH ELASTIC SILT 5 high plasticity SPT DENSITY WL (Completion) CL LEAN CLAY <5 Very Loose low to medium plasticity 5 - 10 Loose WL (Seasonal High Water) CH FAT CLAY 11 - 30

5 - 10 Loose WL (Seasonal High Water) CH FAT CLAY 11 - 30 Medium Dense high plasticity 31 - 50 Dense WL (Stabilized) OL ORGANIC SILT or CLAY >50 Very Dense non-plastic to low plasticity OH ORGANIC SILT or CLAY FILL AND ROCK high plasticity PT PEAT highly organic soils FILL POSSIBLE FILL PROBABLE FILL ROCK 1 Classifications and symbols per ASTM D 2488-17 (Visual-Manual Procedure) unless noted otherwise. 2 To be consistent with general practice, “POORLY GRADED” has been removed from GP, GP-GM, GP-GC, SP, SP-SM, SP-SC soil types on the boring logs. 3 Non-ASTM designations are included in soil descriptions and symbols along with ASTM symbol [Ex: (SM-FILL)]. 4 Typically estimated via pocket penetrometer or Torvane shear test and expressed in tons per square foot (tsf). 5 Standard Penetration Test (SPT) refers to the number of hammer blows (blow count) of a 140 lb. hammer falling 30 inches on a 2 inch OD split spoon sampler required to drive the sampler 12 inches (ASTM D 1586). “N-value” is another term for “blow count” and is expressed in blows per foot (bpf). SPT correlations per 7.4.2 Method B and need to be corrected if using an auto hammer. 6 The water levels are those levels actually measured in the borehole at the times indicated by the symbol. The measurements are relatively reliable when augering, without adding fluids, in granular soils. In clay and cohesive silts, the determination of water levels may require several days for the water level to stabilize. In such cases, additional methods of measurement are generally

nular soils. In clay and cohesive silts, the determination of water levels may require several days for the water level to stabilize. In such cases, additional methods of measurement are generally employed. 7 Minor deviation from ASTM D 2488-17 Note 14. 8 Percentages are estimated to the nearest 5% per ASTM D 2488-17. Reference Notes for Boring Logs (09-02-2021).doc © 2021 ECS Corporate Services, LLC. All Rights Reserved