长江漫滩低路堤基底浅层固化层工作性状数值分析

低路堤可以节约不可再生的土地资源, 浅层固化处置是低路堤软基处理科学、经济的方法。采用现场孔隙水压力静力触探（CPTU）对长江河漫滩相典型非均质性天然沉积软土层进行原位试验。应用二维有限差分方法对平面应变条件路堤荷载作用下有无浅层固化层的软土地基固结排水与沉降进行了仿真模拟，并应用三维有限差分方法对路面车辆重载作用下有无浅层固化层的路基及基底变形进行了三维数值仿真。结果表明：地基浅层固化层的设置改变了地基应力场的分布，通过应力扩散作用减小地基土体的附加应力，进而减小了地基土体的沉降量。基底固化层通过增强路基基底的刚度来增强路基的整体刚度，减小路基的变形，提高路基整体稳定性。

Study of shallow solidified soil layer of low embankment on the Yangtze River floodplain by fast Lagrange method

Low embankment can save the irreproducible land resources. Shallow solidified soil layer is a scientific and economic ground improvement method of low embankment. In this paper, CPTU is applied to the in-situ test of Yangtze Rive floodplain. Based on the test result, consolidation and settlement of the soft ground was simulated with the case of designing shallow solidified soil layer and not designing shallow solidified soil layer under the load of embankment gravity and plain strain conditions. The state of embank and settlement under spacial automobile load are also analyzed by FLAC3D on designing shallow solidified soil layer or not. The results indicate that shallow solidified soil layer changed the stress distribution of the ground, and superimposed stress reduced through stress diffusion effect results in the reduction of the settlement. The study also indicates that the total embankment stiffness increased by the stiffness increase in shallow solidified soil layer, which reduces the vertical displacement of embankment and enhances the embankment stability.