刚-柔性桩复合地基中承载性状原位试验研究

In-situ test of bearing capacity behavior of composite foundation with rigid-flexible piles

为了研究刚-柔性桩复合地基在长期荷载作用下应力场的分布规律,在温州地区开展了原位足尺试验。试验结果表明,地基应力分布与上部结构刚度有关,当上部结构层数较低时,桩间土承担了较高的荷载份额;当上部结构层数较高时,刚性桩和柔性桩桩顶均出现应力集中现象.复合地基中不同部位桩应力随层数增加呈现出不同的变化规律,褥垫层的设置可以减小不同部位桩的应力差异,刚性桩荷载分担比在无褥垫层时比有褥垫层时要大得多.

In-situ tests were carried out in Wenzhou in order to study the stress distribution of composite foundation with rigid-flexible piles under long-term load. Results show that the stress of composite foundation is related with the superstructure rigidity. When the superstructure floor is low, loads are undertaken mostly by soil; when the superstructure floor is high, the stress concentration happens on the top of rigid pile and flexible pile. The pile stress variation rule with floor increment is different at different spots and cushion can alleviate the stress difference. The load sharing ratio of rigid pile in the composite foundation without cushion is larger than that in the composite foundation with cushion.