- Simulation of Strong Earthquake Motion with Explosive Line Source Arrays.
- Abrahamson, G. R.; Lindberg, H. E.; Bruce, J. R.
National Science Foundation, Washington, D.C. Research Applied to National Needs.,
- This report describes an experimental investigation of the feasibility of simulating strong earthquake motion with contained explosive line source arrays. The technique consists of detonating a plane array of vertical line sources placed in the vicinity of the structure to be tested. In a full-scale test the array might measure 100 x 30 feet, consist of 10 to 20 vertical bore holes 30-feet deep spaced on 5- to 10-foot centers, placed about 30 feet from the structure to be tested. Reusable hardware was developed for producing contained explosions in a 1/3-scale source, instrumentation was incorporated for hardware diagnostics and output measurements, reasonable acceleration and frequencies were obtained in soil with the 1/3-scale source, and repeatable results were demonstrated. Estimates based on the authors' current experiments show that in a 100- x 30-foot array, a 5-Hz pulse with a 0.5-g peak acceleration can be produced with less than 100 lb of explosive. A complete train of oscillations typical of strong earthquake motion, with a total duration of 10 s and peak accelerations reaching 1 g, is estimated to require about 500 lb of explosive, fired in 10 detonations.
- Earthquake resistant structures; Explosive charges; Seismic waves; Earth movements; Ground motion; Earthquake engineering; Simulation; Earthquakes