复杂地基加固处理前后拱坝结构特性对比分析

Comparative Analysis on Structure Characteristics of Arch Dam Under Complex Foundation Before and After Reinforcement

为了分析建在复杂地基上的高拱坝在水库蓄水后坝体工作性态受坝肩断层、裂隙等地质缺陷的影响程度,采用结构模型试验及有限元计算方法,对某高拱坝1 760 m典型高程拱圈开展研究,对比分析拱坝在坝肩软弱结构面加固处理前后的结构特性。结构模型试验结果表明:在天然坝基条件下,受坝肩软弱结构面较发育以及两岸地形地质条件不对称等因素影响,拱坝的应力与变位值较大,其分布特征存在明显不对称的特点。采用以混凝土置换为主的措施进行加固处理,并对处理前后的拱坝应力、变位情况进行对比分析,有限元计算结果表明:在左岸布置混凝土垫座以及对软弱结构面进行混凝土置换,可有效提高坝肩岩体的承载力和抗变形能力,同时可调整拱坝体型、改善坝体受力状态,使拱圈应力与变位值减小,左右对称性得到明显改善,具有良好的加固效果。

High arch dam on complex foundation, the working state of dam will have severs impact after reservoir under abutment faults andfissures. In order to analyze the adverse effects, it used the structure model test and finite element method to calculate the high arch ring＇s attypical 1,760 m and comparatively analyzed the arch dam abutment in soft structure plane structure characteristics before and after thestrengthening reinforcement. Through the structure model test study, it shows that in natural conditions, as the asymmetric of dam abutmentin soft developed structure plane and cross strait topographic and geological conditions etc. the dam＇s stress and displacement are larger andthe distribution characteristic is asymmetry obviously. Based on these, it mainly used concrete replacement measures reinforcement to analyzethe dam before and after the reinforcement in stress and displacement. The finite element method analysis results show that the left bankarrange concrete pedestal and the weak structural surface use concrete replacement, can effectively improve the dam abutment rock bearingcapacity and anti-deformation ability, also can adjust the arch dam body and improve the state of stress. The arch stress and displacementvalue have been decreased and the left-right symmetry has been improved significantly so the reinforcement effect is good.