爆破振动荷载作用下填埋场稳定性计算分析

Calculation and analysis of stability of landfills under blasting vibration loads

针对爆破振动荷载作用下填埋场稳定系数分析,建立数学坐标系确定两种形状填埋场每个点的坐标位置,分别采用质心法和积分法计算爆破振动惯性力;考虑渗滤液对填埋体、衬垫界面物理力学参数的影响,建立填埋场沿垃圾坝背和坝底破坏时的三楔体分析模型,列楔体极限平衡方程;借助MATLAB求解爆破振动荷载下任意时刻填埋场沿底部复合衬垫界面滑移的安全系数,通过算例验证楔体极限平衡方程的正确性。结果表明:质心法计算的安全系数时程曲线开始发生变化的时间落后于积分法,且与积分法相比,波动幅度更大,最小安全系数更小,实际安全系数应在两种方法之间。当爆源位于垃圾坝底内边缘下方区域或填埋体底部中点左右区域的下方时,安全系数最小,发生失稳的概率最大。爆破振动频率对填埋场安全系数的影响,积分法得出随着振动频率变大,安全系数总体变化趋势增大,且增加幅度逐渐减小。渗滤液水位显著影响填埋场的稳定性。研究结果对评估填埋场在隧道下穿时的稳定性、优化隧道爆破开挖设计、确保施工安全具有重要意义。

Aiming at the analysis of stability coefficient of landfills under blasting vibration loads,a mathematical coordinate system is established to determine the coordinate position of each point of two kinds of landfills,and the blasting vibration inertia force is calculated by the centroid method and integral method,respectively.Considering the influences of leachate on the physical and mechanical parameters of the interface between landfills and liners,a three-wedge analysis model and the wedge limit equilibrium equation are established when the landfills are damaged along the back and bottom of the refuse dam.The safety factor of sliding along the bottom composite liner interface at any time under blasting vibration loads is solved by the MATLAB,and the correctness of the wedge limit equilibrium equation is verified through an example.The results show that the time when the time-history curve of the safety factor calculated by the centroid method starts to change is behind that of the integral method,and compared with those of the integral method,the fluctuation range is larger and the minimum safety factor is smaller,and the actual safety factor should be between the two methods.When the explosion source is located below the inner edge of the bottom of the refuse dam or below the area around the middle point of the bottom of the landfills,the safety factor is the minimum and the probability of instability is the largest.The effects of blasting vibration frequency on the safety factor of landfill site are obtained by the integral method,as the vibration frequency increases,the overall change trend of the safety factor increases,and the increasing range decreases gradually.The leachate water level significantly affects the stability of landfills.The research results are of great significance for evaluating the stability of the landfills under tunneling,optimizing the design of tunnel blasting excavation,and ensuring the successful tunneling.