Analysis On The Interaction Of Pilescap(Raft)-soil With Different Connection Between Pile Top And Cap(Raft)

The different connected manners of piles and raft (cap) have an influence on piled raft's bearing capacity, deformation behavior and load sharing of piles and soil. Much work have been done in this paper including performing an experimental and numerical analysis on conventional piled raft and piled raft with gap between the pile top and cap, both taken into account the influence of consolidation of soil. The findings reveal that the change with time of pile internal force, shaft resistance, deformation and load sharing of the two type of piled raft. The research and findings of this paper including:1. This paper designed a kind of experiment about visual model test of piled raft. One of the four sides of model tank is plexiglass, which make it possible to observe the deformation of pile and soil when loading. High precise digital pictures were taken to analyze the deformation field of pile and soil by using PostView. At the same time, the strain and shaft resistance can be obtained by the way of electrical measurement.2. The 3D numerical model including single pile without cap, single pile with cap and single pile with gap between the pile top and cap have been built up by ABAQUS software and the operational principle of these kinds of single pile models under the vertical load had been discussed. Put emphasis upon the influence by variation about values of this gap in piled raft's internal force and deformation. It found out the relation between the values of gap and internal force and deformation of piled raft. Also, the accurate differential settlement value and load share ratio of soil and pile can be controlled by presetting the value of this gap in the future.3. The 3D numerical models of piled raft and piled raft with gap between pile top and cap considering the soil's consolidation had been built up under the help of ABAQUS. The rules about these two kinds of models'internal force and deformation along with time variation had been found out. The advantage of the second piled raft on reducing the differential settlement were emphasized. Simultaneously, the influence of soil's long term consolidation upon the internal force and deformation were forecasted.4. This paper built up an 3D numerical model which had one chip tall building with annex–piled raft-soil system. By changing the connected manners of pile and cap under the annex, the advantage on controlling the differential settlement resulted from nonuniform load or variable rigidity of raft by laying out gap between the pile top and cap was brought to light, and this viewpoint and method were new.5. Other than the theory analysis and model test, this paper brought up a new kind construction method on the piled raft with gap between pile top and cap. This method can maintain the effect of gap and strengthen the connect of pile top and cap, in addition, it was very convenient for the constructors.