针对目前堆石坝面膜防渗结构数值计算和结构分析中所存在的问题,对传统的有限元数值计算模型进行了改造和完善,利用一种新的连接单元来模拟土工膜与下部垫层间的界面剪切特性,在提高土工膜防渗结构有限元分析精度的同时不额外增加整体有限元计算的规模,从而能够大大提高计算效率;对于土工膜防渗结构在坝面四周锚固处可能出现的夹具效应,通过添加在锚固处的三维弹簧单元,实现了对锚固处土工膜受力变形特性的有效模拟.计算结果表明,堆石坝坝面防渗土工膜在坝面绝大部分处所受的拉力较小,而在坝面底部锚固处拉应力较大,易发生拉裂破坏.
In the current state, the numerical computation and structural analysis of earth-rock dam impermeable structure present shortcomings. In this paper, we modified and improved the traditional Finite Element Method ( FEM) model by using a new linkage unit to simulate the interfacial shear characteristics between the lower cushion and geomembrane. Additionally we improved the geomembrane finite element analysis accuracy without additional FEM overall size, which can greatly improve the computational efficiency. We successfully simulated the geomembrane force-deformation characteristics at anchoring points for the possible anchoring effect of geomembrane impermeable structure around dam face through adding three-dimensional spring unit at anchor points. The results show that impermeable geomembrane at the top of earth-rock dam face suffered smaller tension, but at the anchoring points at the bottom, it suffered lager tension, so it is prone to tensile crack.