铁路岩溶路基塌陷机理与注浆加固方法

Mechanism Analysis of Railway Karst Subgrade Subsidence and the Corresponding Methods of Grouting Consolidation

浅埋隐伏型岩溶塌陷基本特征是地下水水位变化频繁和地层浅部土洞、溶洞发育,岩溶塌陷的形成往往是多种机制综合作用的结果,如地下水位下降形成真空吸蚀作用、地下水潜蚀作用、列车或采石放炮震动作用等,构成铁路安全营运隐患。针对洛湛铁路益娄段岩溶发育特征与规律,利用粘土固化浆液具备施工成本低、工艺简单易行、堵水防渗及抗震性能好等诸多优势,通过试验确定粘土固化浆液的最佳配比为：粘土粉占20%~45%,水泥占10%~30%,水玻璃占3%~5%,固化剂占1%~3%,粘土原浆漏斗粘度值为30s,对洛湛铁路浅埋隐伏型岩溶路基实行溶洞充填注浆和路基水平帷幕注浆并举加固,加固层的厚度一般为5m左右。经多种手段检验,表明注浆加固工程质量得到很好的控制。

The fundamental features of shallow-hidden Karst subsidence is groundwater going up and down frequently and lots of soil hole and limestone cave existing in shallow stata,which is hidden danger to railway safety.Clay hardening grouts is overwhelmingly superior to others when it is applied for consolidation on shallow-hidden Karst roadbed in Louzhan Railway Line by stuff and horizontal curtain grouting,for example,its lower construction cost,simple and practical technology,good property in intercepting groundwater and anti-seismic capability.By testing,Clay hardening grouts optimum prescription is made up of 20%~45% clay,10%~30% cement,3%~5% water glass,1%~3% special hardening agent and viscosity of mud is above 30s.Shallow-hidden Karst roadbed has been consolidated by stuff and horizontal curtain grouting in Louzhan Railway Line,depth of which is about 5 meters.The outcome of several inspection measurements show a good quality of grouting consolidation constuction has been achieved.