碎石土地基中矩形桩水平承载特性及m值分析

Analysis on horizontal bearing characteristics and m valueof rectangular piles in gravel soil foundation

为探究碎石土地基中桩身抗弯刚度对桩基水平承载特性及地基水平抗力系数的比例系数m值的影响,以桩身等截面积为基准,展开不同抗弯刚度矩形桩水平荷载作用下承载特性研究,并采用m法对其进行计算分析.试验结果表明:桩身位移衰减特征表现为刚性桩时,荷载传递深度是受载边长的8.3倍,表现为柔性桩时,荷载传递深度是受载边长的1.5倍;碎石土地基的m值可在32.9~58.7 MN/m^(4)范围内取值.桩身位移及弯矩的衰减规律表明,桩身抗弯刚度影响桩土荷载传递机理,刚性桩的荷载传递深度较柔性桩大,空间受力更为显著;通过m法计算得到的位移与实测位移吻合,表明m法可作为矩形桩位移计算的预测方法.

To investigate the impact of pile body flexural stiffness on the horizontal bearing characteristics of pile foundations and the proportional coefficient m value of the foundation horizontal resistance coefficient in gravel soil foundations,the load-carrying characteristics of rectangular piles with varying flexural stiffness under the horizontal load are studied based on piles with equal cross-sectional areas,and the m method is used to calculate and analyze them.The test results indicate that the load transfer depth of a rigid pile is 8.3 times the length of the load side,while the load transfer depth of a flexible pile is 1.5 times the length of the load side.The value of m for a gravel soil foundation can be chosen within the range of 32.9 to 58.7 MN/m^(4).The attenuation regularities of pile displacement and bending moment indicate that the bending stiffness of the pile body influences the load transfer mechanism between the pile and soil.Rigid piles have a greater load transfer depth compared to flexible piles,and the spatial force is more pronounced.The calculated displacement using the m method matches the measured displacement,suggesting that the m method can be utilized as a reliable prediction method for calculating the displacement of rectangular piles.