溪洛渡特高拱坝建基面嵌深优化的分析与评价

ANALYSIS AND EVALUATION OF OPTIMIZING DESIGN FOR FOUNDATION EXCAVATION OF XILUODU SUPER-HIGH ARCH DAM

对特高拱坝建基面嵌入深度优化的分析与评价是当前水利工程中的重点研究方向之一,具有重要的学术和工程意义,其研究成果可为制定新的优化与评价标准作参考。在分析国内外特高拱坝建基面优化分析与评价研究现状的基础上,总结特高拱坝建基面优化分析与评价的原则与工作步骤。就建设中的溪洛渡特高拱坝建基面嵌入深度的优化设计,采用三维非线性有限元法和三维地质力学模型试验,对3种建基面嵌入深度方案,即可研方案、优化方案和比较方案的坝体应力、整体稳定、超载能力等进行分析评价。论证溪洛渡拱坝基础利用III1级岩体和上部高程部分利用III2级岩体作为大坝基础的可行性;实施中的建基面嵌深采用优化方案。优化方案较可研方案减少基础开挖和大坝混凝土工程量各100多万立方米,节省直接投资约7亿元,经济效益十分显著。

Analysis and evaluation on optimizing design for foundation excavation of super-high arch dams is one of the most important research fields in hydraulic engineering. It is also significant for engineering and scientific study, and for proposing new design criteria of super-high arch dam or revising arch dam design standard. An evaluation criteria, design concept and flow of optimizing of design are discussed for proposing the analysis and estimation system on optimization of design for foundation interface of super-high arch dam. Based on the study progress of analysis and evaluation on optimizing design for foundation excavation of super-high arch dams, a study on optimizing design for excavated foundation surface of Xiluodu Arch Dam is presented. By employing the 3D nonlinear finite element method and 3D geomechanical model test, different excavated foundation surfaces of Xiluodu Arch Dam including feasible scheme, optimizing scheme and comparative scheme, are analyzed and evaluated respectively. The investigation results demonstrated the feasibility of using III1, and III2 typical rock mass as excavated foundation surface of Xiluodu Arch Dam. The optimizing scheme of Xiluodu Arch Dam, compared with the feasible scheme, the excavation of foundation and concrete quantities of dam will decrease about one million cubic meters; as a result, nearly RMB 700 million of investment is saved.