冲刷作用下单桩水平承载特性试验研究及数值模拟

发布时间：2018-05-31 07:13

  本文选题：桩基础 + 模型试验　； 参考：《水利学报》2015年S1期

【摘要】：为了掌握冲刷前后桩基础水平承载性能的变化规律,通过自行设计加工的水平加载装置,进行了一系列不同冲刷深度下的桩基室内模型试验,获得在不同水平荷载作用下桩头水平位移以及沿桩身的应变,掌握冲刷作用对桩基水平承载性能的影响。在此基础上,采用FLAC3D软件模拟单桩在水平荷载作用下的承载性能,并依据模型试验结果修正数值模型相应参数,获得能考虑冲刷作用影响的单桩计算模型。用该计算模型对冲刷角、桩顶固定方式和不同冲刷深度下单桩的水平承载力性状进行分析,得出如下结论:当冲刷深度小于1.5倍桩径时,水平极限承载力受冲刷影响较小;而当冲刷深度达到大于2倍桩径,小于8倍桩径时,水平极限承载力受冲刷影响较大,下降幅值达到80%;当冲刷深度继续增大,水平极限承载力下降趋于平缓;在一定的冲刷深度下,当冲刷范围变化时,桩基侧向承载力变化不明显;桩头固定有利于减小冲刷对桩基承载力的影响。
[Abstract]:In order to understand the variation law of pile foundation's horizontal bearing capacity before and after scouring, a series of indoor model tests of pile foundation with different scour depth were carried out through the horizontal loading device designed and processed by ourselves. The horizontal displacement of the pile head and the strain along the pile body are obtained under different horizontal loads, and the effect of scour on the horizontal bearing capacity of the pile foundation is grasped. On this basis, the load-bearing behavior of single pile under horizontal load is simulated by FLAC3D software, and the corresponding parameters of numerical model are modified according to the results of model test, and the calculation model of single pile which can take into account the effect of scour is obtained. The calculation model is used to analyze the horizontal bearing capacity behavior of the pile with different scour depth, such as scour angle, pile top fixation mode and different scour depth. The following conclusions are drawn: when the scour depth is less than 1.5 times of the diameter of the pile, the horizontal ultimate bearing capacity is less affected by scour; When the scour depth is more than 2 times of pile diameter and less than 8 times of pile diameter, the horizontal ultimate bearing capacity is greatly affected by scour, the decreasing amplitude reaches 80, and when the scour depth increases, the horizontal ultimate bearing capacity decreases slowly. Under certain scour depth, the lateral bearing capacity of pile foundation does not change obviously when the scour range changes, and the fixing of pile head is helpful to reduce the influence of scour on the bearing capacity of pile foundation.
【作者单位】： 武汉理工大学交通学院结构工程系;
【基金】：中央高校基本科研业务费专项资金资助项目(2014-Ⅳ-108)
【分类号】：TU473.1
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本文编号：1958765