高速铁路深厚软基连续薄板梁结构测试分析

在深厚软土地基上修筑无砟轨道高速铁路低矮路基,需要重点解决好软土地基工后沉降和长期动力稳定性问题.软土地基具有高压缩性,路堤荷载作用下会产生较大的残余沉降;同时,线路运营后,地基土在高速列车长期循环动荷载作用下易产生较大的塑性变形,二者耦合将严重影响到无砟轨道的几何状态和线路运营安全.基于此,在京沪高速铁路上海虹桥深厚软土地区低矮路基中,首次采用了桩基-连续薄板梁结构型式,并进行了系统的静动态监测、测试.结果表明,该结构工后沉降控制效果良好、长期循环荷载作用下性能稳定,可以满足高速铁路铺设无砟轨道和高速列车长期平顺运行的要求.

Experimental Study on Deep Soft Ground of High Speed Railway Treated with Bored Pile-continuous Thin Plate Structure

The settlement and the long-term dynamic stability of soft ground were the key technical problems,when the low subgrade of high speed railway with ballastless track was constructed in deep soft soil region.The soft ground will have large residual settlement under embankment load because of its high compressibility and the foundation soil may have greater plastic deformation arise from long-term large dynamic load in the operation process,which can seriously affects the ride comfort of ballastless track.In order to decrease settlement and improve the long-term dynamic stability of the low embankment on deep soft ground in Shanghai Hongqiao area of Beijing-Shanghai High Speed Railway,the bored pile-continuous thin plate structure was firtstly used with detailed monitoring and testing.The analysis results indicate that this structure has the characteristic of smaller post-construction settlement and better resistance capacity to dynamic load deformation,so it can meet the controlling requirements of ballastless track on high speed railway.