注浆成型螺纹桩抗拔承载特性的数值分析

发布时间：2018-07-05 11:14

本文选题：桩基础 + 注浆成型螺纹桩　；参考：《岩土力学》2014年S2期

【摘要】：注浆成型螺纹桩为一种利用施工工艺创新,结合钻孔灌注和二次注浆技术的新型螺纹抗拔桩型,目前已在软土地区开展应用。为了对其受力承载特性深入研究,使该桩型得到广泛推广,通过数值分析方法对其抗拔性能和承载机制进行了三维有限元数值模拟。首先,通过数值模拟桩-土界面室内大型直剪试验得到了有限元分析需要的桩-土接触面参数,而后将得到的参数带入注浆成型螺纹桩抗拔三维有限元数值模型,通过计算得到了不同距径比S/D(即螺距与桩径的比值)螺纹桩的抗拔荷载-位移曲线和轴力分布,并观察了抗拔过程中桩周土体塑性变形的发展。数值分析表明,螺纹桩与桩周土体的机械咬合作用增大了桩侧摩阻力,从而使桩体极限抗拔承载力较等截面圆桩提高约2~5倍;同时,其承载能力与桩体的S/D有关,当S/D取最优时,荷载-位移曲线的初始切向刚度最大,极限承载力最高,桩周土体形成的连续拱形破坏区域最大。
[Abstract]:The grouting pile is a new type of thread resistant pile using the construction technology innovation, combined with the drilling and two grouting technology. It has been applied in the soft soil area at present. In order to make a thorough study of its bearing bearing characteristics, the pile type has been widely popularized. The anti pull-out property and bearing mechanism of the pile are carried out by numerical analysis method. Three dimensional finite element numerical simulation. First, the pile soil contact surface parameters needed by finite element analysis are obtained by numerical simulation of large direct shear test in the pile soil interface, and then the obtained parameters are brought into the three-dimensional finite element numerical model of the injection molding thread pile, and the ratio of S/D (the ratio of pitch to pile diameter) is obtained by calculation. The anti pulling load displacement curve and the axial force distribution of the screw pile and the development of the plastic deformation of the soil around the pile during the uplift are observed. The numerical analysis shows that the mechanical occlusal effect of the screw pile and the soil around the pile increases the friction resistance of the pile side, so that the ultimate uplift capacity of the pile is about 2~5 times higher than that of the equal cross section pile; at the same time, the bearing capacity and the bearing capacity of the pile are improved. The S/D of the pile body is related. When the S/D is optimal, the initial tangential stiffness of the load displacement curve is the largest, the ultimate bearing capacity is the highest, and the continuous arch destruction area of the soil around the pile is the largest.
【作者单位】：同济大学地下建筑与工程系;同济大学岩土及地下工程教育部重点实验室;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;上海建工集团股份有限公司;
【基金】：上海市重点科技项目(No.11231202002)
【分类号】：TU473.1

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