高面板堆石坝软缝接触计算模型及其数值实现

Algorithm and simulation methods for the soft longitudinal joint of the concrete faces in high concrete-faced rockfill dams

设置软接触纵缝是防止高面板堆石坝发生面板挤压破损的常用工程措施。分析软缝填缝料的挤压特性,提出一个简单实用的双线性软缝挤压模型。通过将软缝概化为可发生相互贯入的软接触界面,提出基于计算接触力学的摄动Lagrange格式,发展相应的软缝接触算法,并采用三维接触分片试验验证算法的有效性。结合天生桥一级面板堆石坝进行计算分析,结果表明设置软缝可有效减低面板的坝轴向挤压应力。

In high concrete-faced rockfill dams（CFRDs）, soft longitudinal joint is an engineering measure widely applied to avoid extrusion damage of the concrete faces. Based on analyzing the compressive features of the soft filler in normal direction, a bilinear compression model was proposed. During the simulation, the soft longitudinal joints are treated as soft contact interfaces, where the penetration represents compressive displacement. Applying the computational contact mechanics, the perturbed Lagrange formulation was proposed to develop a soft joint contact algorithm. The effectiveness of this algorithm was verified by a three-dimensional contact patch test, and then it was applied to Tianshengqiao - I CFRD in China. The numerical results show that soft longitudinal joints can significantly reduce the axial extrusion stress of the concrete faces.