岷江龙溪口水下岩体钻爆的爆破能量特征研究

为研究岷江龙溪口水下岩体钻爆的破岩效率，建立动力有限元模型，对比水与空气耦合介质对爆炸能量传递效率的影响，分析露天与水下爆破中岩体动力响应与能量特征。结果表明，水耦合装药条件下爆炸传入岩体的爆破能量和传递效率大于空气耦合装药条件，可见水介质耦合可以增强破岩效果。在水耦合装药条件下，覆水条件对初始阶段爆炸应力波的传播不存在影响；当压缩应力波从自由面反射后，露天水耦合爆破的单元动能以及内能较大，说明在水下爆破中与自由面接触的水介质抑制了岩体的运动并吸收了部分爆破能量。水下爆破需要增加炸药单耗才能获得露天水耦合同样的爆破效果。

Blasting energy characteristics during underwater rock drilling and blasting in Longxikou of Minjiang River

To study the rock-breaking efficiency of underwater rock drilling and blasting in Longxikou of the Minjiang River,we build a dynamic finite element model to compare the influences of the water-coupled and air-coupled medium on the blasting energy transmission efficiency.Meanwhile,we also analyze the dynamic response and energy characteristics of rock in open-pit and underwater blasting.The results indicate that the blasting energy and transmission efficiency transmitted into the rock in water-coupled powder charge conditions are greater than those in air-coupled powder charge conditions,which shows that a water-coupled medium can enhance the rock-breaking effect.In the water-coupled powder charge conditions,the water-covering conditions have no effect on the propagation of initial explosive stress waves.When the compressive stress wave is reflected from the free surface,the unit kinetic energy and internal energy of open-pit water-coupled blasting are relatively large.This indicates that the water medium in contact with the free surface in underwater blasting suppresses the rock mass movement and absorbs some of the blasting energy.Underwater blasting needs to increase the explosive unit consumption to obtain the same blasting effect as open-pit water coupling.