异形桩桩土荷载传递机理理论分析

发布时间：2018-11-02 16:08

【摘要】：近年来,异形桩成为国内外学者研究的热点之一。所谓的异形桩有两种,第一是通过改变桩身纵向截面形状得到变截面异形桩,第二是通过改变桩截面几何形状得到异形截面桩,其共同目的是通过改变桩身形状来提高桩基承载力。然而,目前的研究仍着眼于异形桩的宏观承载特性上,其复杂的桩土荷载传递机理即异形效应并未得到根本的揭示。通过平衡分析方法得到了考虑桩土剪切作用的单桩荷载传递计算方法,包括桩周土竖向有效应力、桩侧正(负)摩阻力、桩身总侧摩阻力和桩身轴力(下拽力)的计算公式。通过模型试验验证了公式的合理性。通过对比分析等截面面积的圆形桩、H形桩和X形桩,揭示了桩土剪切作用在异形截面桩中的表现,初步探讨了异形截面桩的异形效应。
[Abstract]:In recent years, special-shaped piles have become one of the hotspots of scholars at home and abroad. There are two kinds of the so-called special-shaped pile. The first is to obtain the special-shaped pile with variable cross-section by changing the shape of the longitudinal section of the pile, and the other is to obtain the pile with special-shaped section by changing the geometric shape of the cross-section of the pile. The common purpose is to improve the bearing capacity of pile foundation by changing the shape of pile body. However, the present research is still focused on the macroscopic bearing characteristics of the special-shaped pile, and its complex pile-soil load transfer mechanism, that is, the special-shaped effect, has not been thoroughly revealed. Based on the equilibrium analysis method, a calculation method of single pile load transfer considering the shear action of pile and soil is obtained, which includes the vertical effective stress of soil around the pile, the positive (negative) frictional resistance of the pile side, the total side friction resistance of the pile body and the axial force of the pile body (lower drag force). The rationality of the formula is verified by model test. By comparing and analyzing circular pile, H-shaped pile and X-shaped pile with equal cross-section area, the behavior of pile-soil shearing action in special-shaped cross-section pile is revealed, and the special-shaped effect of special-shaped cross-section pile is preliminarily discussed.
【作者单位】：解放军理工大学爆炸冲击防灾减灾国家重点实验室;河海大学岩土力学与堤坝工程教育部重点实验室;重庆大学土木工程学院;
【基金】：国家自然科学基金项目(51408607,51408187) 中央高校基本科研业务费专项资金项目(2013B01214)
【分类号】：TU473.1

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