This project involved a large deep-seated bedrock landslide which originally activated ,during the intense storms of Jan 3-5, 1982. The slide was almost wholly developed within bedrock strata of the Contra Costa Group at the crest of the Berkeley Hills. The slide was approximately 150 feet wide, 300 feet long and about 35 feet deep, and laterally displaced the Bryant Residence approximately 10 feet downslope from its original position. The slide scarp originally developed within the outboard shoulder of Beloit Drive, eventually closing the road for almost a year. FEMA disaster relief funds allowed for a cooperative repair approach between the County and the residents (Kalker and Bryant). The repair included tiedback caissons with load transfer beams, reaction piers and drilled tiebacks excavated on a pad 6 to 18 feet below finished road grade; then a recompacted buttress fill below the two affected homes. A 30-ft deep trench subdrain was also emplaced beneath Beloit Avenue which drained off to the north, onto an undeveloped native slope.

Schematic of Bedrock Landslide.