基于试桩试验的桩侧注浆抗拔桩承载变形特性的荷载传递法

发布时间：2019-07-13 19:54

【摘要】：依托上海虹桥综合交通枢纽工程开展了4组桩侧注浆抗拔桩的现场试桩试验,得到了各试桩各土层的桩侧摩阻力与桩土相对位移关系曲线(τ-w曲线)。首先,对前述现场试桩试验得到的τ-w曲线以及文献[1]中通过桩土接触面大型直剪试验得到的τ-w曲线进行归一化处理,归一化参数为各土层极限侧摩阻力τult及其相应的临界桩土相对位移wult;然后采用双曲线函数拟合归一化后的各土层τ/τult-w/wult曲线,得到一个统一的τ/τult-w/wult函数关系式;最后,将该双曲线函数应用到荷载传递法中,用于分析预测桩侧注浆抗拔桩的承载变形特性,可求得桩侧注浆抗拔桩桩身各处的荷载-位移曲线、桩身轴力分布曲线以及桩侧摩阻力分布曲线。通过工程案例的验证表明,其计算结果与工程案例实测值较接近,在上海地区具有一定的适用性。
[Abstract]:Based on the Shanghai Hongqiao Comprehensive Transportation Hub Project, the field test of four groups of pile side grouting anti-pullout pile is carried out, and the relationship curve between pile side friction and pile-soil relative displacement (蟿-w curve) of each soil layer of each test pile is obtained. First of all, the 蟿-w curve obtained from the above field pile test and the 蟿-w curve obtained by the large direct shear test of pile-soil contact surface in reference [1] are normalized. the normalization parameters are the ultimate lateral friction of each soil layer and its corresponding critical pile-soil relative displacement wult;. Then the hyperbolic function is used to fit the ult-w/wult curve of each soil layer after normalization, and a unified 蟿 / tau ult-w/wult function relation is obtained. Finally, the hyperbolic function is applied to the load transfer method to analyze and predict the bearing deformation characteristics of the pile side grouting anti-pull pile, and the load-displacement curve, the axial force distribution curve and the pile side friction distribution curve of the pile side grouting anti-pull pile body can be obtained. The verification of the engineering case shows that the calculated results are close to the measured values of the engineering cases and have certain applicability in Shanghai.
【作者单位】：华东建筑设计研究总院地基基础与地下工程设计研究中心;
【基金】：国家科技支撑计划课题(No.2012BAJ01B02);国家科技支撑计划课题(No.2012BAJ07B015)
【分类号】：TU473.1

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