缺陷桩对小型群桩-刚性网格复合地基荷载特性的影响分析

The Influence Analysis of Defect Pile on Small Pile Group and Rigid Composite Foundation Load Characteristics

小型群桩-刚性网格复合地基是一种新型复合地基,由小型群桩、刚性网格和过渡垫层组成,具有荷载传递机制明确、可调节桩土荷载分担比、沉降均匀化以及边缘抗滑移和隆起等特点,在珠三角地区软土地基工程中得到了初步应用,具有推广使用价值。针对复合地基中出现缺陷桩情况,对变形和荷载特性产生的影响进行分析,采用有限元模拟方法对缺陷桩相邻桩顶荷载、网格梁荷载传递以及地基沉降的改变进行分析。结果表明,刚性网格具有对缺陷桩周围桩的荷载进行重新分配、改变桩土荷载分担比、并使沉降均匀化的作用。

Small pile group and rigid composite foundation is a new type of composite foundation which is composed of small group of piles,rigid grid and cushion. This kind of ground has a clear load transfer mechanism,adjustable bearing ratio in piles and soils,even sedimentation and resistance of slide of edge. This work has been applied on soft engineering of Pearl River Delta region initially,with the better value for popularization. For the case of composite foundation with defective piles,the impact of deformation and load characteristics were analyzed by using finite element modeling method especially pile closed defective one butt load,load transfer of grid and foundation settlement. The result shows that the rigid grid has the ability to reassign the load of piles around defective one,change bearing ratio in piles and soils,and make sediment even.