含水土质边坡的爆破振动响应及破坏模式研究

摘要

公路边坡施工期间在频繁遭受爆破振动作用影响的同时,还会经常承受降雨和水位升降变化的影响.为探讨爆破振动荷载与地下水协同作用下土质路基边坡稳定性,建立了土质边坡的有限元模型,研究了爆破振动荷载和地下水协同作用下土质路基边坡的振动响应规律,并建立了几何相似系数为1:10的试验模型,研究了存在地下水和不存在地下水时土质路基边坡在爆破振动荷载下的响应特征,进一步探讨了土质路基边坡在爆破振动作用下的渐进性破坏机理.研究发现:随着地下水位的升高,土质路基边坡不同位置的振动加速度减小;随着地下水位的上升,土质路基边坡不同位置的振动位移逐渐增加,而振动速度减小;在相同水位和爆破振动条件下,沿着边坡高度方向振动位移和振动速度都是减小的.无地下水时,起始于坡脚的震源,坡顶会出现明显的圆弧形滑移破坏,坡脚和坡顶破坏最为严重;有地下水时,坡脚在爆破振动波的作用下发生了拉裂破坏,而坡顶没有出现破坏.%During the construction period of highway slope,the influence of blasting vibration is commonly,which is also affected by rainfall and changes of water level.In order to determine the stability of soil subgrade slope under the influence of blasting vibration load and groundwater,the finite element model of the slope is established,and the dynamic response of the roadbed slope under the coupling of the blasting and groundwater is studied.A test model whose geometric similarity coefficient as 1:10 is established using simulating model test,and indoor model experi-mentation of the slope affected by blasting vibration under different underground water levels is developed.The re-sults show that the blasting vibration acceleration decreases with the increasing of the groundwater levels,and the dis-placement increases with the velocity decreasing.Displacement and velocity decrease along the height of the slope under the conditions of the same water level and blast vibration.When the slope holds no groundwater,the slope top is destroyed.Finally,the slope top and slope foot destruction are most serious,which shows that the slope produces amplification effect on the blasting vibration wave.When the slope holds groundwater,the slope foot is tensiled,how-ever,the slope top is not destroyed.