Research On The Effect Of The Pile Spacing On The Settlement Of The Composite Foundation Using Steel Tube Based On Centrifugal Model Test

The construction of the infrastructure in China develops rapidly since the reform and opening policy, In the course of the construction, some problems about the soft soil occurs. At present, the soft soil processing is mainly by forming the composite foundation to improve the bearing capacity and reduce the settlement of the foundation. Method by using composite foundation with steel pipe pile is a new soil processing method. The pile space is a dominant parameter during the design of the composite foundation. While the research on the effect of the pile space on the settlement of the composite foundation with steel pile is not enough.The article discuss the settlement of the compressive deformation of the stabilized layer the settlement of the underlying layer and the total settlement in the composite foundation from the perspective of the various pile space of the steel pipe pile based on the centrifuge test and the FEM analysis. The article proposes a reasonable range of pile space to provide advice and suggestion for the construction and the control on the settlement of the composite foundation with different space of the steel pipe pile. The main content and the conclusion are as follows:(1) The analysis results of centrifugal model test, the steel pipe pile composite foundation from the basic position of the center point of the farther, settlement deformation is smaller; conversely, from the basic position of the center point of the closer, greater settlement deformation. The settlement of the composite foundation with steel pipe pile is less than the unprocessed foundation, the reinforcement effect in obvious, the smaller the pile space, the larger the replacement ratio is, the smaller the settlement of the stabilized layer is, the larger the settlement of the underlying layer is, when the pile space is bigger, the contrary conclusion is right.(2) The analysis on the effect of the steel pipe pile space on the composite foundation is conducted including the effect on the compression deformation of the stabilized layer and the underlying layer. The reasonable range of the pile space is3-5D that is3or5times of the diameter of the pile based on the centrifuge test.