1996 Singapore Ground Shock Test

Abstract : The 1996 Singapore Ground Shock Test was conducted to document the ground shock and surface ground motions produced by a simulated accidental detonation of munitions in a 1/3-scale underground storage chamber at a nominal loading density of 10 kg/cu m. A secondary objective was to record the airblast levels produced in the connecting tunnels and beyond the tunnel portal. The explosive charge consisted of 696.6 kg of Composition B explosive. The test chamber was located at a depth of approximately 115 m in a limestone geology. The ground motion data from the gages installed in the vertical boorehole are in good agreement with data from previous experiments (UAST) at this site. Comparison of these data and surface values shows that both sets attenuate at the rate of distance to the 2.5 power. The surface motion reflection factor is slightly greater than the theoretical free-surface value but is in good agreement with reflection factors of 3 to 5 that have been observed on underground nuclear tests.