砌石坝综合加固措施的渗流分析

A Seepage Analysis of Comprehensive Reinforcement Measures of Stone Masonry Dams

针对铜鼓县大塅水库运行期存在的一系列安全问题,以6号非溢流砌石体坝段为研究对象,建立了该坝段除险加固前后的三维有限元模型,基于渗流场与温度场的相似性,利用ANSYS热分析模块,分别对运行工况和正常蓄水位工况下该坝段进行了渗流分析计算。结果表明:运行工况下加固后坝段的压力水头计算值与监测点的实测值吻合较好,数值模拟计算所得渗流场整体上能够较好的反映坝体和基岩的渗流场分布特征;正常蓄水位工况下,加固后的坝体自由面、压力水头和渗透压力均显著降低,坝体和防渗帷幕体的渗透坡降都较小;当设有衔接帷幕时,在坝基主帷幕与坝面防渗面板之间区域内水头值明显小于无衔接帷幕情况下该区域内的水头值。可以认为,新设的衔接帷幕能够将坝体防渗体与坝基防渗体有效连接,形成了一个完整封闭的防渗体系;综合加固措施的实施有效改善了坝体的渗流场状况,在防渗处理上能够取得预期的良好加固效果,同时,研究成果可为同类砌石坝工程渗流控制提供参考。

This essay is aimed at the security problems of Tonggu Daduan Reservoir during the operation,focusing on the 6 th non-overflowstone masonry dam section,builds the three-dimension finite element model of the 6 th dam section before and after reinforcement,bases on the similarity of seepage field and temperature field,makes seepage calculation on the dam section under the operation condition and normal pool level condition through the ANSYS thermal analysis module. The results show that the model calculation value of the dam section＇s pressure head agrees well with its monitoring point measured value under operation condition,the seepage filed calculated by numerical simulation can reflect its distribution characteristic of dams and bedrock as a whole. Under normal pool level condition,there is a significant decrease in free surface,pressure head and seepage pressure of the dam section after reinforcement,the seepage gradient of dams and impervious curtain is relatively less. When there is a connection curtain,the pressure head between the main dam foundation connection curtain and the dam surface anti-seepage face slab is obviously less than the pressure head in this section without connection curtain. Above all,The new connection curtain can connect the dam impervious body with the dam foundation impervious body and makes a complete-closed impervious system.The comprehensive reinforcement measure improved seepage filed condition effectively and achieved a predictive effect on anti-seepage treatment. Meanwhile,the research result can provide a reference for this project on the stone masonry dam seepage control.