孔口对混凝土重力坝抗爆性能的影响分析

Effects of Orifices on the Antiknock Performance of Concrete Gravity Dams

为满足防洪、发电、灌溉等需求,混凝土重力坝坝体往往设有很多孔口。当爆炸荷载在这些孔口附近起爆时,势必会对大坝造成一定程度的破坏。本文应用Euler-Lagrangian耦合方法,建立了库水、含孔口坝体、炸药、基岩和空气的全耦合模型,对比分析了挡水坝段(不含孔口坝段)和含孔口坝段在水下爆炸荷载作用下的毁伤特征,研究了孔口的存在对大坝毁伤发展过程和破坏模式的影响。结果表明:当坝体含有孔口时,大坝的整体抗爆性能显著降低,在水下爆炸荷载作用下,大坝将在孔口处形成贯穿上下游的裂缝,导致孔口以上的大坝失去挡水作用。

In order to meet the demands of flood control,power,irrigation,etc.,many orifices are set in concrte gravity dams.When the charge is detonation near the orifice,the explosion load will cause considerable damage to the dam.In the present paper,a fully coupled Euler-Lagrangian model considering the effects of the water-orifice-charge-foundation-air interaction is established.The failure modes and damage distribution of the concrete gravity dam with orifice are compared with the dam without orifice.The influence of the orifices on the dynamic response of the concrete gravity dam is discussed.The results show that the orifice designed on the dam body will significantly reduce of the antiknock safety of the concrete gravity dam.Under close-in underwater blast load,cracks are observed at the orifice region and penetrate the whole section o the dam,which will induce a dam break in the orifice location.