Modification of the Constant Coefficient Method for Horizontal Reaction of Foundation of Rigid Rock-Socketed Piles
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摘要: 随着建筑规模的不断扩大和海洋工程的发展,桩基础须承受的荷载也变得越来越复杂,水平荷载对基础的影响变得越来越显著。JTG 3363—2019《公路桥涵地基与基础设计规范》中对于桩基嵌岩段地基水平抗力系数的计算过于简单,对于大直径嵌岩桩的尺寸效应也没有较好的考虑。针对刚性嵌岩桩的受力特点,基于地基水平抗力常系数的假设考虑了竖向侧摩阻力的影响,提出刚性嵌岩桩水平受荷响应的计算方法,该方法相较于未考虑侧摩阻力的计算结果更加精确。基于现场试验数据通过有限差分软件建立了嵌岩桩数值模型,对岩体力学参数和桩基参数等影响桩岩相互作用的因素进行参数分析,提出了基于地基水平抗力常系数假设的地基水平抗力系数拟合计算式。
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关键词:
- 嵌岩桩 /
- 水平承载力 /
- 地基水平抗力常系数法
Abstract: With the continuous development of construction scale and the offshore engineering, the loads on pile foundations have been becoming more and more complicated and the effect of lateral loads on pile foundations have been becoming more and more notable. The calculation method for the horizontal reaction coefficient of foundation of rock-socketed piles, which is suggested by Specifications for Design of Foundation of Highway Bridges and Culverts JTC 3363—2019, is too simple, and the size effect of large-diameter rock-socketed piles is not well considered. According to the mechanical characteristics of rigid rock-socketed piles, considering the effect of vertical skin friction, a calculation method to determine the response of rigid rock-socketed piles under lateral loads was proposed based on the assumption of a constant coefficient of horizontal reaction of foundation. The calculation results were more accurate compared with the results without considering vertical skin friction. Based on field test data, the numerical models of rigid rock-socketed piles were constructed by a finite difference software, and the parameter analysis on various factors influencing the rock-pile interaction including the mechanical and physical parameters of rock and piles was performed. Eventually, a fitting formula for the horizontal reaction coefficient based on the assumption of a constant coefficient of horizontal reaction of foundation was proposed. -
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