海陆交互相软土区CFG桩复合地基工作机理

Research on Working Mechanism of CFG Pile Composite Foundation in the Interactive Marine & Terrestrial Deposit

依托某滨海水闸地基处理工程,利用数值分析软件,分析了海陆交互相软土区CFG桩复合地基的工作机理。结果表明:随着荷载的增大,桩体荷载分担比随之增大,且桩土应力比与荷载呈现较好的对数增长关系,其对数拟合参数值受褥垫层厚度影响较大;设置褥垫层对复合地基的桩土应力比有显著影响。当不设置褥垫层时,桩顶应力集中明显,不利于土体承载力发挥,降低了其实际承载力;当褥垫层厚度为桩径的一半左右时,复合地基承载力增加较为显著;褥垫层厚度为50 cm时虽然其承载力有所增加,但经济成本相对提高,并且承载力提高幅度不大。

Relying on a coastal sluice foundation treatment project,analysis on working mechanism and application of CFG pile composite founda-tion were carried out with the finite element analysis software. Research shows that,as the load increases,the ratio of load sharing will grow also. The stress ratio of CFG pile and soil shows a logarithmic relationship,thickness of cushion for CFG pile composite foundation give a reasonable in-fluence to logarithmic parameter. Significant performance will be displayed while cushion is set up. When the cushion is disappear,the stress con-centration exists on the top of pile obviously,actual bearing capacity of soil will be cut down and discouraged;while the thickness of cushion is set up about half the diameter of the pile,the growth of bearing capacity of composite foundation will be evident;while the thickness of cushion is 50 cm,the economic costs grow up together and the bearing capacity improving slowly.