In Situ Seismic Investigation, Isabella Project, California
Abstract
An in situ seismic investigation consisting of surface refraction seismic, downhole, and crosshole tests was conducted at Lake Isabella, near Bakersfield, California. Compression and shear wave (P- and S-wave) velocities as a function of depth were determined for the main and auxiliary dams and underlying foundation materials. Results at the main dam indicated four P-wave velocity zones from a surface refraction seismic line located along the crest of the dam. These zones had velocities of (a) 1,750, (b) 2,550, (c) 8,050, and (d) 18,450 fps, which corresponded to (a) random fill material, (b) the central impervious core, (c) weathered granite, and (d) fresh granite. Data at the auxiliary dam were given two separate interpretations. The primary interpretation established three basic P- and S-wave velocity zones with respective velocities of (a) 2,850 and 1,150 fps for the embankment, (b) 6,600 and 1,600 fps for the foundation to bedrock, and (c) 12,100 and 3,300 fps for granite bedrock. The alternate interpretation provided a more detailed profile. Nine P-wave and eight S-wave velocity zones were established ranging from a low of 2,450 and 1,000 fps (P- and S-wave, respectively) to a high of 13,400 fps (P- wave) and 3,750 fps (S-wave) for fractured granite.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1978
- Accession Number
- ADA063168
Entities
People
- Glenn B. Landers
- Joseph R. Curro Jr.