混凝土堆石坝面板变形特性的有限元数值模拟

Numerical Simulation of Deformation Behavior of Concrete-faced Rockfill Dam

根据蒲石河凝土面板堆石坝的实际情况建立三维简化模型,运用大型有限元计算分析软件ANSYS进行三维非线性有限元计算,分析了面板堆石坝的应力应变特点。模拟了在不同蓄水位条件下,混凝土面板垂直缝和周边缝的变形过程。建立了混凝土面板和堆石体之间、混凝土面板与面板之间、混凝土面板与趾板之间的接触模型,采用ANSYS提供的接触单元模拟。数值模拟结果表明:在靠近河谷附近,垂直缝为闭合状态;在靠近岸坡附近,垂直缝为张开状态,其最大开度为2mm,周边缝在河谷附近开度最大,往两岸逐渐减小,最大开度为17.9mm。有限元数值模拟结果为堆石体施工期变形预留和周边缝、垂直缝的接缝材料选取提供了理论依据。

The physical and mechanical characteristics of reck-filled dam are analyzed, and the element type and contact element type are determined. According to experiment data and research results, the Duncan-Chang non-linear constitutive model is selected to denote the stress strain character of rockfill, and the rockfill material parameter is also determined. The incremental construction process of rockfill dams was numerically simulated, using ＂birth and death＂ element supplied by ANSYS. The numerical simulation results indicate that： in the completion period, the maximal vertical deformation which is located on 1/2 height of the dam is 0. 4 m, accounting for 0. 51 percent of the dam height. The maximum horizontal displacement which is located on 1/3 height of the dam is 0. 17 m. The maximum stress in y coordinate is 1.39 MPa; the maximum third principal stress is 0. 14 MPa, which shows that the stress in completion period is mainly caused by the self-gravity of the rockfill body. The deformations of peripheral joints and vertical joints of the concrete face in different periods are simulated. The contact model between concrete face and rockfill body, concrete face and concrete face is done with contact element supplied by ANSYS. The numerical simulation results indicate that： in the nearby river valley, vertical joints are closed; and in the nearby bank, vertical joints are opened. The maximum opening is 2 ram; and in the nearby river valley, peripheral joints have the most maximum opening, which is 17. 9 mm. Finite dement simulation results provide a theoretical basis for deformation reserved in completion period and the joint material of peripheral joints and vertical joints.