爆炸荷载下岩质边坡动力特性试验及数值分析研究

 采用室内混凝土边坡模型试验方法，结合动力有限元程序模拟技术手段，对爆炸冲击荷载作用下岩质边坡的动力特性进行分析研究。研究结果表明：爆破地震波在边坡坡体上的传播及衰减特性与平地不同，质点振速峰值随爆心距的衰减相对要小得多，垂直与水平质点振速峰值衰减指数分别为0.76和0.42。比较坡顶与坡面测点振速发现，坡顶的垂直与水平质点振速峰值均大于坡面质点振速峰值，表明坡顶质点振速存在放大效应。比较迎爆侧3#测点与背爆侧4#测点的质点振动峰值，垂直和水平方向振速峰值分别降低72.7%和67.6%。由此可见，采用减震沟减震措施可以大大降低爆破振动强度，并能有效改善冲击荷载作用下边坡的应力状态。另外，比较试验与计算结果得出，质点振速及回归方程指数与试验数据均在同一量级上，坡顶质点振速随高程增加而放大，可见数值计算结果能很好反映实际爆破振动规律。

MODEL TEST AND NUMERICAL SIMULATION STUDY OF DYNAMIC CHARACTERISTICS OF ROCK SLOPE UNDER BLAST LOADING

The indoor experimental method of concrete slope model and finite element model are considered to study dynamic characteristics of rock slope under blast loading. The result shows that the propagation law and attenuation characteristics of the detonating earthquake wave on slope are different to the condition of level ground，and the attenuation of peak particle vibration is small with distance. The vertical and horizontal attenuation indices of peak particle vibration are 0.76 and 0.42，respectively. Comparing the peak particle vibration of the top and other particles of the slope，peak particle vibrations of the top particles are larger than those of other particles，so there are vibration enlarging effect at the top particles of the slope. Comparing the peak particle vibration of point No.3 facing blasting source and point No.4 backing blasting source，the peak of vertical velocity is reduced by 72.7% and the peak of horizontal velocity by 67.6%，so the measures of damping ditch can reduce the value of peak particle vibration greatly and can improve the stress state of the slope under blasting load. With the experimental results，the particle velocity and the index of regression equation are in the same magnitude with the test data，and the peak particle velocity increases with its height，too. The calculation results can give the reality particle vibration law of the slope under blast loading well.