In Situ Seismic Investigation of Coyote Dam
Abstract
An in situ seismic investigation consisting of surface refraction seismic, downhole, and crosshole tests was conducted at Coyote Dam, near Ukiah, California. Compression- and shear-wave (P- and S-wave) velocities as a function of depth were determined at two cross sections of the dam (sta 118+00 and 126+00). P- and S-wave velocity profiles were also determined for the materials which comprise the left abutment. The profiles constructed for the dam showed that P-wave velocities in the core increased from 2100 to 4000 fps with depth. The random fill section of the dam was determined to have a velocity of 3600 fps. A horizontal gravel blanket drain underlying the random section was determined to have a velocity of 4800 fps. The P-wave velocity of the dam's foundation materials had velocities ranging between 4100 and 7600 fps. The S- wave velocity profiles showed that velocities in the dam's core increased from 850 to 1250 fps except at sta 126+00 where a velocity of 950 fps was noted for the lower 50 ft of core material. The random fill section of the dam had a velocity of 1400 fps, with its underlying horizontal gravel drain having a velocity of 1600 fps. The foundation materials were determined to have velocities between 1450 and 2650 fps. The materials on the left abutment displayed P-wave velocities ranging between 1600 and 5500 fps. The S-wave velocities for these materials ranged between 850 and 1950 fps.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1981
- Accession Number
- ADA098051
Entities
People
- José L. Llopis
- Robert F. Ballard Jr.
- Ronald E. Wahl