刘家箐水库大坝安全性分析

Dam safety analysis of Liujiajing reservoir

在高震区易液化的全风化花岗岩地基上修建心墙堆石高坝,用于防渗的土料为易液化低粘粒含量的全风化花岗岩砂土,基础及坝体的动力安全性是坝体设计中的关键问题。通过采用各筑坝料的静、动力试验研究成果,对大坝典型设计剖面进行了静、动力有限元数值分析,对坝体安全性进行了论证,结果表明:坝体在静力荷载作用下是安全的;坝体在动力荷载作用下,若遇8度地震,上游坝脚处的基础全风化砂层和坝体上游面残坡积土斜墙防渗体可能发生液化,下游坝脚剥离弃料坡面可能发生剪切破坏,将影响大坝的稳定安全。

When the high rockfill dam with core wall is built on the fully weathered granite foundation, liable to liquefication in strong seismic area, and the materials used as seepage prevention are fully weathered granite sand and soil with low percentage of clayey grain, liable to liquefication, the dynamic stability of the dam and its foundation body is the key issue in dam design. Through static and dynamic tests of various dam building materials, the static and dynamic finite element analyses of the typical dam section are carried out to demonstrate the dam safety. The analysis results show that the dam is safe under static load; but under the condition of dynamic load and encountering 8 grade earthquake, the full weathered sand layer of the foundation at the dam heel and the inclined seepage prevention body of residual clinosol on the upstream surface of the dam are possible to incur liquefication, the shearing failure of stripped spoil slope at dam toe may occur and influence the dam safety.