静钻根植竹节桩抗拔承载性能试验研究

为了研究静钻根植竹节桩的抗拔承载性能,进行了静钻根植竹节桩抗拔静载试验。通过一组破坏性抗拔试验得到了完整的静钻根植竹节桩抗拔荷载位移曲线,并采用幂函数、双曲线和指数函数分别对试桩荷载位移曲线进行了拟合;通过桩身埋有应力计的静钻根植竹节桩的抗拔试验分别对其桩侧摩阻力与桩端阻力进行了研究。试验结果表明:静钻根植竹节桩抗拔荷载位移曲线比较平缓,采用指数函数对其进行拟合的效果较好;静钻根植抗拔桩中水泥土与桩周土接触面摩擦性质比灌注桩中桩土接触面摩擦性质要好,静钻根植抗拔桩的桩侧摩阻力是钻孔灌注桩的1.47~2.11倍;静钻根植抗拔桩中桩端水泥土扩大头能够提高桩基桩端阻力,而且能够提高靠近桩端处桩身与土体接触面的摩擦性质。

Behavior of the static drill rooted nodular piles under tension

A series of field tests on static drill rooted nodular piles are conducted to investigate their behavior under tension. A group of destructive field tests are conducted to investigate the load-displacement response of the static drill rooted nodular piles under tension. Moreover, the power function, hyperbolic function and exponential function are used to fit the load-displacement curves of the test piles, respectively. Field tests on the static drill rooted nodular piles instrumented with strain gauges are conducted to investigate their skin friction and mobilized tip resistance. The test results show that the load-displacement curves of the static drill rooted nodular piles under tension are relatively flat, and that the exponential function can be used to fit the curves well. The frictional capacity of the static drill rooted nodular piles is better than that of the bored piles, and the skin friction of the static drill rooted nodular piles is about 1.47~2.11 times that of the bored piles. The existence of the enlarged cemented soil base of the static drill rooted piles can improve the capacity of the tip resistance as well as the frictional capacity of the pile-soil interface close to the enlarged base.