云南泥炭质土层劲性复合桩承载力特性研究

Study on Bearing Capacity of Stiff Composite Pile in Peat Soil in Yunnan Province

泥炭质土作为云南地区特有的土质,是一种特殊的软土地基,这使得桩基的选择成为重中之重。劲性复合桩作为一种新型组合桩型,是利用水泥土桩内部插入相应芯桩组合而成,对整体承载性能有很大提升,并且对软土地基处理有着良好的效果。本文通过室内模型试验,研究不同芯桩长度及不同截面大小的劲性复合桩的荷载—沉降曲线、桩身轴力及桩身侧摩阻力,得出劲性复合桩在荷载作用下的承载特性。试验表明:劲性复合桩荷载沉降曲线呈“缓降”型,表现为大直径桩的承载特性;芯桩承担主要荷载,轴力与摩擦力在芯桩底端截面处发生突变。

Peat soil is a special soft soil foundation in Yunnan,which makes selecting pile foundation of top priority.As a new type of composite pile,rigid composite pile is formed by inserting corresponding core pile into cement soil pile,which greatly improves the overall bearing capacity and has good effect on soft soil foundation treatment.In this paper,through the indoor model test,the load-settlement curve,axial force and side friction of rigid composite pile with different core pile lengths and section sizes are studied,and the bearing characteristics of rigid composite pile are obtained.The test results show that the load settlement curve of the rigid composite pile is‘slow drop’type,which shows the bearing characteristics of large diameter piles.The core pile bears the main load,and the axial force and friction force change abruptly at the bottom section of the core pile.