高速铁路地基土压缩模量确定方法比较研究

为掌握高速铁路复合地基中天然土层压缩模量准确简便的确定方法,以武广客运专线12个试验断面和京沪高速铁路4个试验断面路堤设计参数和地基处理情况为依据,分别采用E1-2法和e-p曲线法确定各天然土层压缩模量,计算地基沉降值并将其与实测沉降值进行比较。结果表明:对于浅薄地层地基而言,路堤高度略大于5 m(不超过7.5 m)时,E1-2法的计算沉降值与e-p曲线法相比误差小于10%,路堤高度小于5 m时,两者误差随路堤高度减小而增大,但是控制在30%以内;为简化运算,可以采用E1-2法代替e-p曲线法计算浅薄地层地基沉降;对于深厚地层而言,E1-2法计算沉降值明显大于e-p曲线法,其误差随压缩层厚度增大而增大,故不宜采用E1-2法计算深厚地层地基沉降。

Comparison of Methods for Calculating Ground Soil Compression Modulus of High-speed Railway

12 test sections from Wuhan-Guangzhou passenger railway line and 4 sections from Beijing-Shanghai high-speed railway are selected to master the method for calculation of ground soil compression modulus in high-speed railway composite foundation. Based on the embankment design data and foundation treatments,both method and e-p curve method are used to ascertain the nature soil compression modulus. Moreover,the foundation settlement is calculated and comparison of the calculated settlement is conducted with the actual settlement. The results show that for the shallow strata,the error of the method is less than 10% compared with e-p curve method when the embankment height is slightly larger than 5 meters( less than 7. 5 meters),while the error is increased as the embankment height decreases when the height is less than 5 meters,but it's less than 30%; method may be used to replace e-p curve method to simplify the calculation in the shallow strata; the calculated settlement with methodis obviously larger that of e-p curve method in the deep strata,the difference of the two methods is increased as the compression thickness increases, so method is not recommended to calculate the settlement of deep strata.