Accession Number : ADA956455

Title :   Seismic Tunnel Detection Using Underground Explosive Sources.

Descriptive Note : Final technical rept.,

Corporate Author : SOUTHWEST RESEARCH INST SAN ANTONIO TX

Personal Author(s) : Fountain, Lewis S. ; Owen, Thomas F.

Report Date : 15 DEC 1967

Pagination or Media Count : 121

Abstract : This report summarizes the results of an experimental investigation of a seismic method of shallow tunnel detection using a small subsurface explosive detonation as the seismic excitation source. A special tunnel test facility was constructed in homogeneous soil near San Antonio, Texas to allow the detection concept to be evaluated under idealized field conditions. Seismic measurements were made in the vicinity of small explosive charges consisting of from 2 to 8 ounces of dynamite exploded at depths ranging from 6 to 40 feet below the surface. The seismic response of the ground both near and away from the tunnel was measured using multi-channel seismic recording techniques. In these tests, the experiments were designed to reveal the anomalous ground response and peculiarities of seismic wave propagation in the vicinity of the tunnel as compared with the response measured under similar geometrical conditions away from the tunnel. The data collection equipment consisted of standard geophysical instrumentation modified for high frequency close-range operation using accelerometer sensors as well as specially assembled laboratory equipment which allowed precision wide bandwidth seismic ground motion measurements to be made using high sensitivity accelerometers. All data were recorded on magnetic tape.

Descriptors :   *SEISMIC DATA, *SEISMIC DETECTION, *TUNNELS, *SEISMIC WAVES, SUBSURFACE, EXPLOSIVES, DETONATIONS, DYNAMITE, WAVE PROPAGATION, GEOPHYSICS, ACCELEROMETERS, MAGNETIC TAPE.

Subject Categories : Seismic Detection and Detectors
      Seismology
      Civil Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE