既有南昆线膨胀岩(土)路基病害类型、原因及增建二线路基处理方案

Type and Reason of Disease of Expansive Rock and Soil Subgrade on Existing Nan-Kun Railway and Treatment Scheme of Newly-built Second Line

南昆铁路膨胀岩(土)路基病害以广西南宁,百色盆地为典型。南宁盆地膨胀红黏土的天然含水量大、天然孔隙比、液限、塑限、塑性指数、压缩系数一般比百色盆地膨胀岩要高,但膨胀性能却比百色盆地膨胀岩低,显示膨胀岩比膨胀红黏土具有更强的膨胀条件,相比之下膨胀岩路基地段病害相对集中。通过归纳既有南昆铁路百色段膨胀岩土路基病害类型并分析病害产生原因,以及既有病害整治原则及其效果,增建二线膨胀岩(土)路基处理措施及针对不同的膨胀性路堑基床采用的处理方案,以减少路基病害发生。

The expansive rock and soil subgrade disease in Nanning and Baise basin of Guangxi is quite typical on Nan-Kun Railway.The physical index of swelling red clay in Nanning basin,such as Natural moisture content,natural void ratio,liquid limits,plastic limits,plastic index,compression coefficient is higher than that of expansive rock in Baise ba-sin,however,the expansive property is lower,which indicates the expansive rock has more expansive conditions than the swelling red clay,therefore,there are more subgrade diseases in the section of expansive rocks.In this paper,by sum-marizing the disease types of expansive rock and soil subgrade in the existing Nanning-Baise section,analyzing the cau-ses,diseases treatment principle and its effect,the expansive rock and soil subgrade treatment measures of newly-built second line and corresponding treatment schemes for different expansive cutting foundation beds are put forward in order to reduce the production of subgrade diseases.