中文摘要：

以京沪高速铁路京徐试验段DK190＋ 124-DK190＋ 354试验工点的CFG桩网和桩筏复合地基为例,通过比较和分析铁路地规法、铁路桥规法和M-B联合e-lgp法3种解析方法以及数值模拟法的计算结果,研究适合计算高速铁路CFG桩复合地基沉降的方法.研究表明：铁路地规法以土为主的沉降计算思路会导致计算地基的加固区沉降时结果偏大,M-B联合e-lgp法由于计算的加固区附加应力整体偏大,也同样会造成加固区沉降的计算结果较大,而采用这2种方法计算地基的下卧层沉降结果较为合理;采用M-B联合e-lgp法计算时,对于浅部土层的附加应力,应按照桩间土顶面的应力线性减至零进行计算,之下土层的附加应力应按照Mindlin方法进行计算;铁路桥规法由于计算过程过于简化,忽略了加固区的变形,计算得到的沉降结果全部由下卧层产生,导致计算的下卧层应力偏大,因此沉降的计算结果偏差最大,该方法不适合较低刚度CFG桩复合地基的沉降计算;用数值模拟方法计算的加固区和下卧层沉降结果均较接近实际.

英文摘要：

Three analytic methods,namely,Technical Code for Ground Treatment of Railway Engineering （method one）,Code for Design on Subsoil and Foundation of Railway Bridge and Culvert （method two）,Mindlin-Boussinesq uniting with e-lgp curves （method three） and one numerical method were used to calculate the settlement of the same experimental site which was located between Jing-Xu test section DK190 ＋124-DK190＋354 of Beijing-Shanghai high-speed railway reinforced by CFG-Geosynthetics and CFGRaft method,in order to compare their applicability.Studies show that the first method which emphasizes more on the importance of soil among piles will result in greater calculated settlement of the reinforced zone.The calculated settlement by the third method is also greater because of greater total additional stress.But the calculated settlement of substratum by these two methods is reasonable.In order to improve the third method,the additional stress of the upper part of reinforced zone should be calculated and decreased linearly to zero,and the additional stress of the lower part of reinforced zone can be calculated by the Mindlin method.Because the calculation process of the second method is rather simple and without regard to the deformation of the reinforced zone,the calculated settlement is of substratum and the calculated stress of substratum is greater.The deviation of the calculated settlement is the greatest,so the second method is not suitable for composite foundation grouted by CFG piles with low stiffness.The calculated settlement of the reinforced zone and substratum by numerical method is in good accordance with test results.