五星形桩截面尺寸优化及竖向承载机制试验研究

发布时间：2018-03-22 05:13

  本文选题：五星形桩　切入点：截面尺寸优化　出处：《岩土力学》2017年10期 　论文类型：期刊论文

【摘要】：五星形混凝土桩是一种新型截面异形桩,由圆截面均匀内切5个圆弧形成,其截面参数主要有被切割圆半径R、切割圆半径r、切割圆弧所对应的外包圆圆心角2x、外包圆弧对应圆心角θ。经截面尺寸优化分析,推导出周长最大化五星形桩和周长面积比最大化五星形桩。为进一步掌握五星形桩承载性能,以砂雨法制作土样,在干砂中进行了4根单桩对比模型试验研究,4根单桩为:周长面积比最大化五星形桩F_2、周长最大化五星形桩F_1、与F_2等截面周长圆桩C_1、与F_2等截面面积圆桩C_2。试验结果表明:与F_1相比,F_2的桩侧表面积与其相近,极限承载力大致相同,但F_2混凝土用量是F_1混凝土用量的0.75倍,单位体积混凝土承载力更高,F_2为最优的截面尺寸;与等截面面积小圆桩C_2相比,F_2桩侧表面积是其1.53倍,极限承载力是其2.4倍,显示出在相同混凝土用量下五星形桩F_2具有良好的承载性能,截面异性扩大效应明显;与相同截面周长的大圆桩C_1相比,F_2桩截面面积是其0.44倍,极限承载力是其0.96倍,但F_2桩单位体积混凝土承载力是C_1桩的2.21倍,显示出更高的承载性价比。各级荷载作用下五星形桩侧摩阻力所占比例在80%以上,特别是F_2桩,在90%以上,表现出摩擦桩的特性。研究成果可对五星形桩的工程应用提供一定理论支持。
[Abstract]:The five-star concrete pile is a new type of special-shaped pile with cross section, which is formed by 5 circular arcs with uniform internal tangent of round section. The cross section parameters mainly include the cutting circle radius R, the cutting circle radius r, the outer circle center angle 2 x corresponding to the cutting arc, the outer arc corresponding to the center angle 胃. The maximum circumference five-star pile and the circumference area ratio maximization five-star pile are deduced. In order to further understand the bearing capacity of the five-star pile, the sand rain method is used to make the soil sample. Comparative Model Test of four single piles in dry Sand four single piles are as follows: maximum circumference area ratio maximization of five-star pile F2, maximum circumference maximization of five-star pile F1, C1s with F2 equal-section circular pile C1 and F2 with F2 iso-section circular pile C2.Tests are carried out. The results show that the surface area of the pile side of FSP _ 2 is similar to that of FSP _ 1. The ultimate bearing capacity is approximately the same, but the amount of Fstack _ 2 concrete is 0.75 times that of F# _ 1 concrete, and the bearing capacity of unit volume concrete is higher than that of F-1 concrete, and F _ S _ 2 is the best cross-section size, and the surface area of Fstack _ 2 pile is 1.53 times than that of small circular pile C _ (2) with equal cross-section area. The ultimate bearing capacity is 2.4 times higher than that of the pile, which shows that FSP _ 2 has good bearing capacity under the same concrete content, and the cross-section anisotropic effect is obvious, and the cross-section area of FSP _ 2 pile is 0.44 times that of large circular pile with the same circumference. The ultimate bearing capacity is 0.96 times higher than that of C-1 pile, but the bearing capacity of FSP _ 2 pile is 2.21 times of that of C _ S _ 1 pile, which shows a higher ratio of bearing capacity to price. The proportion of lateral friction of five star-shaped piles under various loads is over 80%, especially for F2 pile, which is above 90%. The research results can provide some theoretical support for the engineering application of five-star pile.
【作者单位】： 河南理工大学土木工程学院;浙江大学城市学院土木工程系;
【基金】：国家自然科学基金(No.51508166) 河南省教育厅科技攻关项目(No.14A560015)~~
【分类号】：TU473.1
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本文编号：1647210