不同破坏准则下防渗墙安全度比较分析

为分析和评估土石坝覆盖层中混凝土防渗墙安全度,将混凝土的三维破坏准则引入有限元程序中,对某砾石土心墙堆石坝进行了有限元分析,定义了防渗墙安全度,并将三维破坏准则的安全度与单轴破坏准则结果进行了比较,研究不同破坏准则适用于混凝土防渗墙安全度分析的合理性。结果表明:单轴破坏准则和三维破坏准则得到的防渗墙安全度有较大差异,采用混凝土三维破坏准则更符合防渗墙所处的应力状态,可更充分发挥混凝土的强度;在工程中可考虑采用三维破坏准则评价混凝土防渗墙安全度。

Analysis of safety factor of diaphragm wall with different failure criteria

In order to accurately estimate the safety of the concrete diaphragm wall of earth rockfill dams,two types of three-dimensional(3D) failure criteria for concrete were coded into a finite element program and were used to analyze the safety factor of the diaphragm wall of an earth rockfill dam.In this study, the influence of the different failure criteria on the safety of diaphragm wall were investigated by comparing the values of the safety factors estimated with the 3D failure criteria and the one-dimensional(1D) failure criteria.The results indicate that the value of the safety factor estimated with the 3D failure criteria is quite different from that estimated with the 1D criteria.The 3D criteria were also found to be more suitable for the stress state of the diaphragm wall and could give full play to the strength of concrete.The 3D criteria of concrete were recommended to estimate the safety factor of a concrete diaphragm wall in the engineering applications.