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U.S. Department of Energy
Office of Scientific and Technical Information

US Geological Survey investigations in the U12n. 03 drift, Rainier Mesa, Area 12, Nevada Test Site, Nevada

Technical Report ·
OSTI ID:6838636

The U12n.03 drift was designed for a nuclear test site and mining was started on April 18, 1966, and completed May 22, 1967. The drift was driven along a bearing of N. 26/sup 0/ W. at an elevation of 1849.2 m (6067 ft) to a total length of 660.2 m (2166 ft). The drift lies entirely within tunnel bed 4 of Tertiary age and crosses at nearly right angles, the Aqueduct syncline, a prominent geologic feature in Rainier Mesa. A combination of faults cutting nearly parallel to the drift, weak clay-rich tuff, and excessive ground water, all occurring in the trough of the syncline caused severe construction and support problems. These geologic factors created weak plastic rock that resulted in swelling and squeezing ground. Remedial measures were initiated that only temporarily stabilized ground and water conditions. The drift was eventually abandoned for the purposes of a nuclear test site and was subsequently used as a water storage facility. The US Geological Survey performed seismic velocity, electrical resistivity, and geologic surveys in the U12n.03 drift to provide information needed for site evaluation. Electrical resistivity measurements indicate that sections of rock which may be potentially unstable for tunnel construction due to the presence of clay may be defined by this technique.

Research Organization:
Geological Survey, Denver, CO (USA)
DOE Contract Number:
AI08-76DP00474
OSTI ID:
6838636
Report Number(s):
USGS-OFR-80-1074
Country of Publication:
United States
Language:
English