3.1 Field Exploration & Testing • Review of existing data, desktop geologic and utilities research. • Utility locating/clearance; traffic control and ROW permitting support. • Subsurface investigations: soil borings (hollow-stem auger, rotary wash), rock coring (NX or similar), test pits, CPT, geophysical screening as applicable. • In-situ tests: SPT (ASTM D1586), Texas Cone Penetrometer (TCP), field density (ASTM D6938), vane shear, permeability/infiltration (e.g., ASTM D3385), field resistivity/corrosivity, groundwater monitoring (piezometers/observation wells) and seasonal groundwater evaluation where warranted. 3.2 Laboratory Testing (TxDOT/ASTM/AASHTO as applicable) • Index tests: moisture content, Atterberg limits, hydrometer & sieve analysis, specific gravity; organic content. • Strength/settlement/swell: unconfined compression, consolidated/undrained triaxial, 1-D consolidation, swell pressure, collapse potential, direct shear. • Durability/chemical: sulfate/chloride, pH, resistivity, corrosion potential, soluble salts, SAR/PSI as needed. • Aggregate and base materials characterization, including LA abrasion, soundness, and deleterious content. • Stabilization design testing with lime/cement/fly ash and verification of PI, UCS, durability index, etc. 3.3 Engineering Analysis & Recommendations • Foundations: shallow and deep foundation recommendations, bearing capacity, settlement, uplift, lateral resistance; corrosion mitigation; drilled shaft and pile design parameters. • Pavements: subgrade characterization, stabilization recommendations, design inputs (e.g., CBR/ resilient modulus), and pavement structure recommendations for city streets, alleys, and parking. • Retaining walls & earth structures: active/passive earth pressures, global/slope stability, underdrainage, and wall backfill guidance. • Embankments & excavations: slope stability, construction sequencing, temporary shoring criteria. • Drainage & detention: infiltration/permeability data for LID features; subgrade preparation and underdrain criteria. • Seismic/geologic hazards: site classification (IBC/ASCE 7), liquefaction screening where warranted.
