混凝土面板堆石坝地基防渗墙塑性损伤数值分析

在坝体填筑和水库蓄水作用下,防渗墙工作和受力条件复杂,可能产生塑性应变和墙体开裂。本文结合实测资料和数值分析,研究面板堆石坝深覆盖层地基防渗墙的应力变形和损伤特性。在基于实测资料分析防渗墙应力变形特性的基础上,采用混凝土塑性损伤模型,建立防渗墙应力变形及损伤特性的三维数值计算模型。数值模型考虑坝体和地基渗流-应力耦合效应及墙体与覆盖层的接触效应,真实模拟坝体填筑和水库蓄水过程。在采用实测资料验证数值计算结果的基础上,结合实测和数值结果深入分析了面板堆石坝防渗墙的受力机制及其应力变形和损伤开裂特性,讨论了防渗墙位置、材料、坝体和地基渗流-应力耦合作用对墙体力学特性的影响。研究结果对面板堆石坝防渗墙建设和结构安全控制具有一定的指导意义。

Numerical analysis of plastic damage of concrete cutoff wall for concrete face rockfill dam

Under the action of dam filling and reservoir impoundment, the working and stress conditions of the cutoff wall are complicated,which may cause plastic strain and wall cracking. This paper combines the measured data and numerical analysis to study the stress, deformation and damage behaviour of the cutoff wall of a concrete faced rockfill dam. Based on the analysis of the stress and deformation characteristics of the cutoff wall on the basis of measured data, the plastic damage model of concrete is used to establish a three-dimensional numerical model for the mechanical behaviour of the cutoff wall. The numerical model considers seepage-stress coupling effect of the dam and foundation and the contact effect between the cutoff wall and the overburden, and truly simulates the process of dam filling and reservoir storage. The numerical calculation model is verified by the measurement data. The force mechanism and its stress deformation and damage cracking characteristics are deeply analyzed combining with the measurement data and numerical results. The effect of the seepage-stress coupling effect of the dam and foundation, wall position, and wall material on the mechanical behaviour of the cutoff wall is discussed. The research results have guiding significance for the construction and structural safety control of cutoff walls of concrete face rockfill dams.