Subsurface Characterization

Subsurface conditions are characterized utilizing several methods including auger, air-rotary and rotary wash drilling and sampling, Cone Penetration Testing (CPT), test pit excavation and sampling, and seismic refraction surveys.

Laboratory Testing

Herzog Geotechnical staff have extensive experience in classification, strength, and specialty geotechnical laboratory testing. All laboratory test results are reviewed by a registered professional.

Foundation Engineering

Based on engineering analyses, our staff develops suitable alternatives for shallow or deep foundation support, along with recommended bearing and passive pressures, skin friction, minimum embedment depths, and calculated elastic and consolidation settlements.

Lateral Support Systems

Our engineers evaluate alternative means of providing temporary or permanent lateral support for cut or fill slopes, or for stabilization purposes. Our expertise includes developing geotechnical criteria for conventional retaining walls, cantilevered or tiedback sheetpiles, soil nailing, post-tensioned tiebacks or rock anchors, segmental reinforced earth walls and tiedback mesh systems.

Geologic Hazards Evaluations

Potential geologic hazards are evaluated by our engineers and consulting Certified Engineering Geologist. These include fault rupture, ground shaking, liquefaction, densification, landsliding and tsunami or seiche inundation. Evaluations are performed in accordance with California Geological Survey guidelines.

Earthquake Site Response

Our engineers develop seismic design parameters for structural design, liquefaction evaluation or slope stability analyses. Peak ground accelerations are developed utilizing deterministic and probabilistic methods, and site-specific response spectra are calculated using equivalent non-linear methods.

Slope Stability Analyses

Static and seismic slope stability analyses are performed for cut and fill slopes, earth dams, refuse and liner systems and levees utilizing two and three dimensional methods. Seismically induced slope deformations are calculated based on the results of site response analyses and laboratory test results. Based on stability analyses, stabilization measures are developed to increase the factor of safety or reduce seismic deformations to an acceptable level.

Expert Witness Services

Our consulting personnel include professionals with B.S., M.S., and Ph.D. degrees along with extensive engineering and construction experience.  We provide expert witness services during both litigation and dispute resolution.

Construction Observation and Testing

Our engineers and field technicians have extensive experience in providing observation and testing during earthwork grading, utility trenching, foundation excavation, pier drilling, pile driving, tieback installation and testing, subgrade preparation and paving and installation of subsurface drainage.