基于响应面法的岩溶区堤坝注浆帷幕设计优化研究

Study on Optimization of Grouting Curtain Design of Damsin Karst Areas Based on Response Surface Methodology

帷幕注浆是解决岩溶区堤坝渗漏问题的有效措施,为优化岩溶区堤坝注浆帷幕设计,有效控制坝基渗流量和渗透压力。首先,采用多场耦合软件构建了岩溶区堤坝帷幕服役模型,提出了岩溶区堤坝帷幕服役性能评价标准;其次,基于Box-Behnken响应面试验设计,建立了岩溶区帷幕渗透系数、帷幕高度、帷幕宽度与帷幕体内Ca(OH)2溶蚀率之间的回归模型;最后,以满足帷幕服役性能条件下最小帷幕注浆量为优化原则,基于Matlab中的fmincon函数建立了岩溶区注浆帷幕设计参数优化模型,求解某岩溶区险情堤坝帷幕设计参数的最优组合。研究结果表明:帷幕渗透系数是影响岩溶区堤坝帷幕体内Ca(OH)2溶蚀率最重要的因素,其次是帷幕高度与帷幕宽度;考虑到工程安全性和经济性要求,建议该岩溶区堤坝帷幕设计采用帷幕高度15.80 m、帷幕宽度4.51 m的参数组合。研究结果可为岩溶区堤坝帷幕服役性能评估提供参考,也可为岩溶区堤坝注浆帷幕设计优化提供新思路。

Curtain grouting is an effective measure to solve the seepage problem of dams in karst areas.In order to optimize the grouting curtain design of dams in karst areas and effectively control the seepage flow and pressure of the dam foundation,a curtain service model of dams in karst areas is firstly built by using multi-field coupling software,and the evaluation standard of curtain service performance of dams in karst areas is put forward.Secondly,based on experimental design of Box-Behnken response surface,a regression model among curtain permeability coefficient,curtain height,curtain width,and Ca(OH)2 dissolution rate in the curtain body in karst areas is established.Finally,according to the fmincon function in Matlab,a model for optimizing design parameters of grouting curtain in karst areas is established,and the optimal combination of design parameters of curtain of a dangerous dam in the karst area is solved by taking the minimum curtain grouting amount as the optimization principle under the condition of satisfying the curtain service performance.The results show that the curtain permeability coefficient is the most important factor affecting the Ca(OH)2 dissolution rate in the dam curtain in karst areas,followed by the curtain height and width.In view of the safety and economic requirements of the project,it is suggested that the curtain height of 15.80 m and the curtain width of 4.51 m should be adopted in the curtain design of the dam in the karst area.The research results can provide a reference for evaluating the service performance of dam curtain in karst areas and offer a new idea for optimizing the design of grouting curtain of dams in karst areas.