淤地坝蓄水加固改造方案的渗流和稳定性分析

Seepage Field and Stability Analysis of the Scheme of Water Storage Reinforcement and Reconstruction of Warping Dams

为对淤地坝进行蓄水加固改造,基于流固耦合理论和强度折减法,应用ABAQUS有限元软件,对贺家庄淤地坝蓄水运行进行了渗流和稳定性分析,提出了黏土斜墙、土工膜等防渗改造思路,计算分析了各改造方案的稳定性和渗流特性。结果表明:采用的数值模拟方法与常用的传统方法比较是可行的;贺家庄骨干淤地坝作为水土保持工程措施,原设计不考虑长期蓄水,若按设计标准正常蓄水,其稳定性不满足要求,需进行加固改造,且仅使用上游坝坡放缓的方式很难达到预期的效果;土工膜改造方案和黏土防渗斜墙改造方案均能提升坝体安全系数、降低浸润线位置和减少渗透量;在原坝体上游坡铺设土工膜方案和铺设厚度为3 m的黏土斜墙均能满足稳定性要求。

In order to impound and reinforce warping dams,based on the fluid solid coupling theory and strength reduction method,this paper analyzed the seepage and stability of Hejiazhuang warping dam during its impoundment operation by using ABAQUS finite element soft⁃ware,put forward the ideas of seepage prevention and reconstruction such as clay inclined wall and geomembrane and calculated and analyzed the stability and seepage characteristics of each reconstruction scheme.The results show that:the numerical simulation method used in this paper is feasible compared with traditional methods;as a water and soil conservation measure,Hejiazhuang main warping dam did not consider long⁃term water storage in the original design.If the water storage is normal according to the design standard,its stability does not meet the requirements,so it needs to be reinforced and reconstructed,and it is difficult to achieve the expected effect only by using the way of upstream dam slope slowing down;both the geomembrane reconstruction scheme and the clay inclined wall reconstruction scheme can improve the safety coefficient of dam body and reduce the position of phreatic line and reduce the seepage;the scheme of laying geomembrane on the upstream slope of the original dam body and the laying of clay inclined wall with the thickness of 3 m can meet the stability requirements.