沉降控制复合桩基承载力发挥性状研究

基于前人的研究成果提出改进广义剪切位移法,结合以往学者的研究成果和实测数据,对沉降控制复合桩基的极限承载力发挥性状做了分析.另外,还通过考虑桩土相对滑移的三维弹塑性有限单元法,分析了桩端持力层刚度对沉降控制复合桩基承载力发挥性状的影响.分析表明,沉降控制复合桩基的极限承载力大小可认为与承台底土极限承载力和群桩极限承载力之和大小相当;桩端持力层刚度对复合桩基的承载力发挥起显著影响作用,桩端持力层刚度越高,桩的极限承载力越难以完全发挥,沉降控制复合桩基的极限承载力将小于群桩极限承载力与承台底土极限承载力之和.

A Study on Bearing Capacity Exertion Behavior of Settlement Controlling Composite Pile Foundation

According to previous studies,the bearing capacity exertion behavior of settlement controlling composite pile foundation is analyzed by using modified generalized shear displacement method,combined with previous results and measured data.In addition,the 3D elastic-plastic FEM considering the relative slippage between pile and surrounding soil is also executed.Thus the influence of the soil property under pile end on the bearing capacity exertion behavior of composite pile foundation is discussed in this paper.It shows that the total limit bearing capacity of settlement controlling composite pile foundation can be regarded as the sum of pile group limit bearing capacity and soil limit bearing capacity under cap,and that the rigidity of soil under pile end can have great effect on the bearing capacity exertion behavior of pile.The higher the rigidity of soil under pile end,the more difficult the exertion of pile limit bearing capacity,and the much less the total limit bearing capacity than the sum of limit bearing capacity of pile group and soil under cap.