多桩复合地基承载特性的现场试验研究

Experimental study on the bearing characteristics of composite foundation

对多桩复合地基进行了现场测试,研究复合地基在受力和破坏的整个过程中,中心桩、角桩、边桩的桩身轴力分布以及荷载传递特性,进而研究加载过程中桩与桩间土的荷载分担比例。同时,研究刚性桩的桩侧土体沿深度方向的沉降变化规律,考察桩侧摩阻力的形成机制和作用机理。研究表明,当采用较大的桩间距时,适当增加桩的长度是有意义的,此时桩侧的摩阻力得到充分发挥,它是桩体承载力得到发挥的本质所在。

The mechanical characteristics and bearing capacity of piles in composite foundation are investigated in field. The process of stress and failure of piles with increasing loading are discussed, including the distribution of axial force and bearing characteristics of central pile, angle piles and side piles. Based on this, the sharing ratio of stress between piles and soil are analyzed. In the meantime, the settlements of soil layer around piles along depth are analyzed, including the formation mechanism and action mechanism of lateral friction. Studies show when greater spacing of piles is adopted, the bearing capacity can be increased by increasing the length of piles. At this time, the lateral friction of piles act on an important effect.