后处理二元复合地基作用机理与变形计算

在路基后处理技术的基础上研究提出一种对部分填土路基水泥土桩复合地基,采用小桩后处理技术,形成双层复合地基的路基后处理技术.具体为:预先采用水泥土搅拌桩处理地基、进行部分路基填土施工,然后在填土标高施工无砂混凝土进行后处理,可用于静态设计工程,也可用于动态设计工程.研究表明,该技术具有硬壳层的扩散作用、刚性垫层作用、小桩对路堤的加固锚固等效应,沉降变形计算可采用上下刺入法、复合模量分层总和法计算,复合模量分层总和角点法计算时,可将路基荷载等效成矩形分布的荷载分层作用在地基上,分别计算,然后相加得到.该方法在大广高速公路扶项段台后高填方软土地基得到了成功应用.

Working Mechanism and Deformation Calculation of Post-Processing Dual Composite Foundation

In this paper,based on subgrade post-processing technology,a post-processing technology was proposed adopting small pile post-processing technology to form double-deck composite foundation for part-filled subgrade cement-soil pile composite foundation.The process includes the first treatment of the foundation adopting cement-soil milling pile and the fill construction of part subgrade,and subsequent post-processing construction with non-sand concrete at the fill elevation.This technology can be applied for both static and dynamic design project.The results show that this method possesses some good properties,such as hard-shell diffusing effect,rigid cushion effect,consolidation effect to the subgrade with small pile,the sedimentation can be calculated using up-down-pierce method and composite modulus layer summation method.When adopt,subgrade loads in the composite modulus layer summation method can be equal to equivalent rectangle distributing load on foundation by layer,which can be calculated separately and counted up.This method has been successfully applied in the Da-Guang freeway project.