中国西南岩溶地区缺水问题有望通过修建水库蓄水来解决,但该区域内广泛发育的岩溶漏斗、落水洞等会使水库内蓄水渗漏。灌浆帷幕是降低库区岩层渗透性的有效手段,低成本高质量帷幕灌浆的关键在于优化灌浆工艺及其参数。采用室内试验、数值模拟和现场试验相结合的方法,对灌浆材料配比、钻孔间距、灌浆压力、帷幕底界和灌浆工艺进行优化。结果表明:将水灰比控制在1∶1~1∶3之间,单排钻孔布置,孔距2.0 m,灌浆压力1~2 MPa,帷幕底界控制深度为风化层深度以下10 m处,分段灌注且第一、第二及以后各段的长度分别为2、3、5 m,可实现德厚库区灌浆帷幕体系透水率＜5 Lu的目标。该研究可为德厚库区灌浆帷幕工艺参数优化提供理论与试验支撑,为西南岩溶发育区类似项目的建设提供参考。

Water shortage in the karst areas of southwest China is expected to be solved by building reservoirs to store water.However,the widespread development of karst funnels and sinkholes in this area will cause the leakage of water storage in the reservoir and finally result in the failure of water conservancy projects.Grouting curtain is an effective means to reduce the permeability of rock in the reservoir area.The key to accomplish the project with low cost and high quality is to optimize the grouting curtain process and its parameters.In this research,the mix proportion of grouting material,the spacing between boreholes,the grouting pressure,the bottom boundary of curtain,and the grouting techniques were optimized by combining laboratory experiment,numerical simulation,and field test.Results demonstrated that the permeability of grouting curtain system in Dehou reservoir area can be controlled less than 5 Lu if the following conditions are met:water-cement ratio is controlled between 1∶1-1∶3,the boreholes are arranged in a single row with the hole spacing at 2.0 m,the grouting pressure is 1-2 MPa,the control depth of the curtain's bottom boundary is 10 m below the depth of the weathering layer,the grouting is carried out in segments,and the length of the first,second and subsequent segments are 2 m,3 m and 5 m,respectively.The research findings offer theoretical and experimental support for the optimization of grouting curtain parameters in Dehou reservoir area,and also provide reference for similar projects in karst area in southwest China.