Research on Working Properties of Composite Ground with CFG Piles
|School||Chinese Geology University (Beijing)|
|Keywords||composite ground Cement Flyash Gravel Pile finite element ANSYS finite element analysis Cushion pile-soil stress ratio bearing capacity settlement composite modulus。|
We all know that composite ground has been widely used in engineering becauseit can enhance bearing capacity of natural ground with relatively small cost. However,further research is necessary as theoretical study is far behind pratice and precisetheory and design method are still not available. The following questions arediscussed in this paper:1. The vertical loading on CFG pile composite foundation is beared by co-actionamong pile capushion, pile and the earth. By using of ANSYS FEM program, thecharacteristics of single pile are studied with pile axis stress ,pile-soil stress ratio andsettlement changed by factors such as loading, thickness of the earth, length ofpile,and etc. Futhermore, group piles and single pile composite foundation whichanalysed by finite element analysis is expounded in this paper.2. Compared with pile foundation, settlement of composite foundation is muchgreaterthough it can control distortion of foundation better as rigidity pile compositefoundation. CFG pile composite foundation adapt the double-control design methodwhich is based on the theory of settlement control can satisfy intensity and distortion,is more rigorous and reasonable than that based on the theory of bearing capacity.This paper analyse practical value of the calculating method of composite modulusand point out insufficiency of the formula by combining with engineering examples.3. This paper also put forward some experiences of design and construction bywith engineering examples.