中文摘要：

通过现场试验对比分析了双向水泥土搅拌桩和常规搅拌的桩身强度、复合地基承载力和路堤荷载下的沉降特性．在现场试验的基础上，以三维数值模拟对路堤荷载下双向搅拌桩和常规搅拌桩复合地基的工作性状进行了对比分析．结果表明，复合地基载荷试验因受荷载作用面积和时间的限制，影响深度浅，不能反映路堤荷载下的实际工作性状．与常规搅拌桩复合地基相比，双向搅拌桩由于桩身质量均匀，下部桩体强度较高，在路堤荷载作用下加固区下部的桩身荷载相对较大，而桩间土附加应力相对较小，从而减小了复合地基地表沉降和坡角侧向位移，即双向搅拌桩在提高工效的同时，提高了复合地基加固效果．

英文摘要：

Compared with ordinary mixing column foundation, the column strength, bearing capacity and settlement of slurry double mixing soil-cement column composite foundation under embankment load were analyzed through the field tests. The behavior of the slurry double mixing and ordinary deep mixing column composite foundation under embankment load analyzed by 3D numerical simulation. The results indicate that the load test can not represent the behavior of composite foundation under embankment load limited by load area and time. As a result of its uniform column quality, the under- side column load of slurry double mixing column is larger while additional stress of surrounding soil is lower than that of ordinary deep mixing column composite foundation, thus it can decrease the surface settlement and lateral displacement at embankment foot. It is concluded that the slurry double mixing technique can improve the treating effect and construction efficiency.