NEHRP Clearinghouse

Simulation of Strong Earthquake Motion with Contained-Explosive Line Source Arrays, Single-Source and Array Tests at Camp Parks.
Bruce, J. R.; Lindberg, H. E.; Abrahamson, G. R.
National Science Foundation, Washington, DC. Engineering and Applied Science., March 1979, 75 p.
An earthquake simulation technique to aid in the design of earthquake resistant structures is reported. In-situ structures are tested to observe vibration modes and explore potential damage mechanisms in complete soil-structure and internal equipment systems. The technique produces earthquake-like ground motion by simultaneous detonation of a planar array of vertical line sources placed in the soil near the structure to be tested. Both amplitude and frequency are controlled at levels suitable for testing with the source arrays close to the test structure. Tests at one-third scale are described in which single line sources and an array of several sources are implemented. These tests have demonstrated that reasonable amplitudes and frequencies can be coupled into the earth with a minimum of explosive and with no surface eruptions. The tests also show that repeatable results can be obtained with reuse of the same line sources. Plans for testing both single source and multiple source arrays using larger scale models are described. An analytical solution to measure stress, strain, and displacement around a pressurized elliptical hole is given in the appendix.
Seismic design; Earthquake resistant structures; Explosive charges; Seismic waves; Earth movements; Earthquake engineering; Simulation; Soil structure interactions; Earthquakes