Impacts of local scour on lateral bearing behavior of partially embedded single piles
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摘要: 为分析局部冲刷对部分埋入桩水平承载性状的影响,利用有限元软件ABAQUS模拟水平荷载作用下部分埋入单桩的受力。根据实际工况建立了部分埋入水平受荷桩的三维有限元计算模型,并将计算结果与现场试验结果进行对比,验证了所建模型的正确性。然后,通过算例分析了冲刷角度、深度、桩直径、桩顶约束条件和桩自由段长度对部分埋入桩水平承载性状的影响。分析结果表明:局部冲刷深度比冲刷角度对部分埋入桩的水平承载性状影响更大,局部冲刷对直径较大的桩体承载能力影响也更大,自由段长度的增大减小了桩体水平承载力,因此,在研究冲刷对桩基水平承载性状的影响时,应结合桩顶约束条件综合考虑。Abstract: In order to study the impacts of the local scour on the lateral bearing behavior of the partially embedded single piles, the software ABAQUS is used to simulate the response of a laterally loaded single pile. According to the application to engineering practices, a 3D finite element analytical model for the partially embedded piles under the conditions of lateral loads is established in this study. The validity of the numerical model is demonstrated by comparing the numerical results with the field experimental results. After then, some numerical examples are selected to investigate the influences of the scour slope, scour depth combined with pile diameter, constraint conditions at the pile head and the free length of piles on the lateral bearing behavior of the partially embedded piles. The analysis results show that the local scour depth has more significant influence than scour slope on the lateral bearing behavior. In addition, the scour conditions also have greater impacts on the lateral bearing capacity of the larger diameter piles, the increase in the free length of piles will result in the decrease in their lateral bearing capacity, and the constraint conditions at the pile head should be considered in the analysis of the impacts of scouring on the lateral bearing behavior of the pile foundations.
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表 1 土体参数
Table 1. Properties of soil mass
土层 厚度/m 弹性模量/MPa 泊松比 黏聚力/kPa 摩擦角/(°) 重度/(kN·m-3) 海洋黏土1 6.3 5 0.49 15 0 17.5 海洋黏土2 10.2 15 0.49 30 0 17.5 淤泥 5.5 27 0.49 70 24 17.8 残积土 2.0 35 0.49 70 34 18.0 风化岩石 3.4 110 0.25 - 32 20.2 软岩石 - 200 0.25 - - 20.5 表 2 模型桩土参数
Table 2. Parameters of pile and soil for numerical model
类别 弹性模量/MPa 泊松比 黏聚力/kPa 摩擦角/(°) 重度/(kN·m-3) 厚度/m 桩 200 000 0.167 - - 50.0 - 第1层土 7 0.490 32 24 17.5 10 第2层土 30 0.300 48 34 20.5 15 -
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