Application Research On The Granular Column In Subgrade Treatment In Soft Ground

Soft deposit has low bearing capacity and high compressibility so that when building, road and/or other structures are constructed on this kind of soft ground, the soft subsoil should be treated to guarantee the quality of the construction. There are many soft ground improvement technologies invented during the past 30 years such as granular column method, deep mixing method, quicklime pile method, jet-grouting method, earth reinforcement and so on. Each technique has its own behavior and scope of application. Granular column can be used to treat the weak subsoil of cohesiveless sandy type soil such as backfill soil, sand deposit and cohesive soil such as silt, clay, and silty clay ground. The improvement effect of granular column is replacement, reinforcement, and drainage. This method has many merits, i.e. improvement of the bearing capacity of the composite foundation, increasing the rigidity of composite foundation, making the construction convenient, simple constructional material, short construction period, low construction cost and so on.The background of this research is an Expressway Project from Yuanmou to Wuding in Yunnan Province, China. Field construction tests were conducted on some experimental sections. The tests include settlement, lateral displacement.Finite element method (FEM) is employed to analyze the settlement and deformation of composite foundation improved by granular column. The load-time-settlement relation is calculated using FEM and compared to the field measured data. Based on the field test and analytical results, following...