Dynamic Lateral Earth Pressure on Underground Structures

摘要

The dynamic lateral earth pressures resulting from underground detonation can cause severe damage to underground structures. The shock exerted on an underground structure caused by an underground explosion will vary with the detonation depth, the intensity of detonation force, and distance of detonation source from the underground structure. This study includes a preliminary investigation of the lateral propagation and attenuation of shock waves, and the accompanying response of a subsection of an underground structure, caused by an underground shock (impulse load) emanating from a source located within the soil adjacent to the structure. This paper describes four large-scale impulse tests on a 1.0 m-high prototype subsection of an underground structure subjected to controlled impulsive lateral loadings propagating through a 0.75 on-thick backfill soil. The response of the subsection to the impulsive loading is carefully monitored utilizing an extensive instrumentation program. The test results provide insight into the phenomenon of shock wave propagation caused by an impulsive loading emanating from an underground source adjacent to the underground structure. The tests indicated that the damaging effect of impulse loading increased with surcharge pressure (depth) until a 'threshold' surcharge pressure is reached above which the damaging effect of impulse loading decreased.