新坝基础开挖爆破对老坝安全影响的动力分析

Dynamic Analysis of Influence of New Dam Foundation Excavation Blasting on Safety of Old Dam

摘要: 根据设计院提出的新坝基础开挖爆破设计方案，参考其他工程施工爆破的实验资料和经验公式，确定爆破所产生的冲击波。采用显示动力有限元法(LS-DYNA)，在模拟老坝三条纵缝的前提下，对冲击振动所导致的老坝重点部位的振速、变形及应力等进行分析评价。计算结果表明，新坝基础开挖爆破时：① 拟定的新坝基础开挖爆破最大单响药量能够满足工程爆破安全要求；② 老坝坝体应力不大，能满足规范要求；③ 老坝坝体纵缝安全允许振速取为3.0 cm/s是合适的。

Abstract: According to the design data of excavation blasting of new dam foundation proposed, the shock wave generated by the blasting is determined according to the experimental data and the empirical formula of other engineering blasting. The dynamic finite element method (LS-DYNA) is used to simulate the old dam’s 3 longitudinal seams, and vibration speed, deformation and stress of im-portant parts of the old dam caused by blasting are analyzed and evaluated. Under the new dam foundation’s excavation and blasting, the calculation results show: 1) the maximum single shot dose of excavation blasting of the new dam foundation proposed can meet safety requirements; 2) the stress of the old dam body is small and can meet requirement of the specification; 3) it is ap-propriate to allow the vibration velocity to be 3.0 cm/s.