ENGEO performed an emergency response geologic hazard assessment following a large landslide failure that impacted the parking lot and improvements at the northeast corner of the Bay Park Senior Living and Retirement Community building located in Pinole, California. ENGEO performed a drone topographic survey, performed subsurface exploration, provided geologic and geotechnical design criteria for temporary and permanent repair design options, installed and monitored inclinometers, and provided ground-improvement quality control and quality assurance (QA/QC) for the landslide repair.
ENGEO teamed up with a design-build contractor to support construction of a tiered temporary soil nail wall with a grade-beam and deep tie-back anchors to temporarily support the headscarp of the landslide and prevent further upslope migration of the headscarp. The team also developed a permanent repair that consisted of an A-frame micro-pile structure with tie-backs through the cap beam to support an MSE wall below the above parking lot and existing community building. Through monitoring data from inclinometers and Automated Motorized Total Station sensors, ENGEO was able to monitor the active movement of the landslide during the repair operations in a cost effective manner. ENGEO also performed testing and observation services during improvement construction of the impacted utilities onsite.
Since the onset of the landslide was relatively abrupt, the north wing common area of the building was temporarily restricted for use by the residents. As ENGEO and others were able to provide emergency response consultation and construction, the residents within the community building were able to return to the restricted area safely within a few months.
ENGEO provided continuous inspection and construction consultation, helping to ensure the improvements followed the project plans and specifications for the various field conditions encountered.