LAUSR

Reservoir impoundment is related to several hydraulic engineering concerns, including irreversible valley contractions, landslides and reservoir-induced earthquakes. However, these phenomena, such as valley contractions, are hardly to be explained by the conventional method. The scientific understanding of water effects during impoundment and their hazards to hydraulic structure are needed. The effective stress law for fissured rock masses is introduced in the elasto-plastic model employing the Drucker-Prager criterion and implemented in the three dimension (3D) nonlinear finite element method (FEM) program Three-dimensional FINite Element (TFINE). The slope deforms towards river-way during impoundment since the increasing pore pressure in fissures changes stress state and leads to additional plastic deformation in the rock materials. The value of Biot coefficient and the influence of water on rock materials are discussed in detail. Thus, the mechanism of slope deformation during the impoundment of Jinping-I arch dam is revealed, and the deformation is accurately measured. The application of the effective stress law provides a method to consider stress assessment, deformation evaluation and stability estimate of hydraulic structures during the impoundment process. This is a beneficial exploration and an improvement of hydraulic engineering design.摘要近年来, 随着锦屏一级、 溪洛渡等一批高坝大库开始蓄水运行, 诱发的不可逆谷幅收缩等问题日益引起工程界的重视。 但是, 这些现象很难被经典的研究或设计方法解释, 科学的理解蓄水过程中山体内水的影响是解释这些现象的基本。 本文提出裂隙岩体有效应力原理, 将其引入到基于 Drucker-Prager 准则的弹塑性模型并在三维非线性有限元程序 TFINE 中实现, 发现蓄水过程中岩体的裂隙水压力增加是导致塑性变形是谷幅收缩的重要原因。 通过在锦屏一级拱坝蓄水过程的谷幅变形分析验证了该方法的可靠性。