Living in California means living with geologic hazards: active faulting, landslides, unstable soils, and debris flow risks. We offer comprehensive assessment of geologic constraints and hazards to support project planning, design, and compliance with local regulations such as the City of San Francisco's Slope Protection Act. 

We provide the full range of studies required by California's Alquist-Priolo Act to evaluate surface fault rupture hazard to new and modified structures for human occupancy in designated Earthquake Fault Zones. A basic study includes site reconnaissance, review of historic aerial photographs and available geologic mapping and subsurface information. Exploratory backhoe trenches may also be logged to precisely locate fault strands and identify the most recent age of movement. See About Earth Focus for our fault experience.

Landslide evaluation may be limited to reconnaissance-level geologic mapping, historic aerial photograph review, and general recommendations for project planning. We can expand this basic scope to characterize slope failures in detail. This may include logging exploratory backhoe trenches, logging and sampling small-diameter exploratory borings, and down-hole logging of large-diameter borings. We also partner with geotechnical engineers to assist in the design and implementation of landslide repairs.

We provide the studies required by California's Seismic Hazards Mapping Act to assess potential liquefaction and seismically induced landslide risks to new and modified structures for human occupancy in designated Seismic Hazard Zones. This includes site reconnaissance and, like Alquist-Priolo investigation and landslide evaluations, may also require detailed geologic mapping and various kinds of subsurface exploration

We are one of the few northern California firms to provide down-hole visual logging of large-diameter borings, a proven method of exploring deep landslide shear planes. A vertical shaft more than 30 inches in diameter is drilled to depth, and our geologist is lowered into the boring in a protective cage to characterize subsurface geologic conditions in detail. Video logs and photography can be provided.

We provide rock coring services for projects small and large. This can involve continuous coring and logging to depths of more than 1,000 feet below the ground surface. Examples of our larger rock coring projects include the SFPUC's Mountain Tunnel (Hetch Hetchy system) project, the Transbay JPA's Downtown Rail Extension Project, and the Transbay Terminal Project.

Geologic mapping is a critical tool for understanding of site conditions and constraints. We provide it as a stand-alone service when requested, and often recommend it as an integral part of our other investigations.

We install and monitor slope inclinometers to measure shallow downslope soil creep and deeper landslide movements, tracking slope instability over time. This is a key tool to gain a better understanding of site-specific slope failure risks and the mechanics of individual failures.

Detailed evaluation of bedding and joint attitudes provides insight into landslide failure mechanisms and can provide important information for landslide mitigation and foundation design.