Model tests on dynamic response of XCC pile-raft composite foundation under different embankment heights
SUN Guang-chao1,2,3, KONG Gang-qiang1,2, LI Jian-lin1, LUO Ya3
1. Key Laboratory of Geological Hazards on Three Gorges Reservoir Area, China Three Gorges University, Yichang 443002, China; 2. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai University, Nanjing 210098, China; 3. Bureau Public Works of Longgang District, Shenzhen 518100, China
Abstract：In order to investigate the influences of embankment height on the dynamic response of pile-raft composite foundation, a large-scale model test on the cast-in-situ X-shaped concrete (referred to as XCC) pile-raft composite foundation is carried out in a model box of 5 m× 4 m×7 m. Four different embankment heights are modeled as the dead loads, and the cyclic wheel axle load is applied to the raft so as to obtain the dynamic response with the dead loads (i.e., embankment height). The results show that the velocity response decreases by 34% ~ 40% from the top of the raft to 0.36 m depth of foundation due to the existence of a gravel cushion. The vibration of the raft caused by the axle load decreases gradually with the increasing dead loads. The relationship between the velocity response of the raft v' and the dead load x is defined by the equation, v' = 12.648-0.519x+0.007x2. Both the dynamic soil stress on the surface of the foundation σsd and the dynamic stress at the top of the pile σpd decrease linearly with the increasing dead loads x. The former is defined by the equation σsd = 7.629-0.085x, whereas the latter is defined by σpd = 284.978-3.660x.
孙广超, 孔纲强, 李建林, 罗雅. 不同路堤高度下X形桩-筏复合地基动力响应模型试验[J]. 岩土工程学报, 2021, 43(zk2): 45-50.
SUN Guang-chao, KONG Gang-qiang, LI Jian-lin, LUO Ya. Model tests on dynamic response of XCC pile-raft composite foundation under different embankment heights. Chinese J. Geot. Eng., 2021, 43(zk2): 45-50.
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