悬浮能量桩-筏基础的热-力学特性数值模拟

1.上海理工大学环境与建筑学院,上海200093;2.上海交通大学船舶海洋与建筑工程学院,上海200240;3.河海大学土木交通学院,江苏南京210024

岩土工程;能量桩;桩-筏基础;群桩效应;热-力学特性;数值模拟

Numerical simulation of thermo-mechanical behavior of floating energy pile-raft foundation
YANG Tao1,CHEN Yang2,KONG Gangqiang3

1.School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, P. R. China;2.School of Naval Architecture, Ocean&Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China;3.College of Civil and Transportation Engineering, Hohai University, Nanjing 210024, Jiangsu Province, P. R. China

geotechnical engineering; energy pile; pile-raft foundation; pile group effect; thermo-mechanical behavior; numerical simulation

DOI: 10.3724/SP.J.1249.2022.01067

备注

针对温度荷载与力学荷载共同作用下砂土地基中的悬浮能量桩-筏基础,建立热-力学响应分析的三维非线性有限元数值模型,研究能量群桩效应、桩间土的温度变化以及能量桩数量和布设方式对桩身附加轴向应力和桩头差异沉降的影响.结果表明,升温荷载作用下,能量群桩内部任意一个桩的桩身附加轴向压应力比单桩作为能量桩时要小得多;在部分能量桩-筏基础中,能量桩的附加压应力沿桩长呈抛物线分布,数值随能量桩数量的增加而减小;非能量桩的附加轴向应力沿桩长呈S形分布,非能量角桩和边桩的上部出现附加拉应力,数值随能量桩数量的增加而增大;能量桩的布设方式对能量桩附加轴向应力有较大影响,但对非能量桩附加轴向应力的影响较小;能量桩非对称布设时桩头间的差异沉降较大,桩周围土的温度取决于其周围能量桩的数量.
The 3D nonlinear finite element model is developed to investigate thermo-mechanical response of a piled raft equipped with floating energy piles on sand subjected to combined thermo-mechanical loadings. Attention is focused on thermally induced group effects,the variations in temperature of the surrounding soil and the effect of the number and the layout of the energy piles on the thermally induced additional axial stress in piles and the differential settlements among the pile heads. The results show that when all the piles are heated,the additional axial compressive stress is much smaller for a pile in the energy pile group than that for single energy pile in the same group. In a pile-raft foundation with partial energy pile,the additional axial compressive stress is distributed in parabolic shape along the energy pile,and it decreases with the increasing number of energy piles. While the additional axial stress in a non-energy pile is distributed in S shape,and the additional axial tensile stresses in the upper parts of non-energy corner piles and edge piles increase with the increase of the number of energy piles. The layout of energy piles has great influence on the additional axial stresses in the energy piles,but has insignificant effect on the additional axial stresses in the non-energy piles. The maximum differential settlement among the pile heads is larger when the layout of energy piles is asymmetrical. The temperature of the surrounding soil depends on the number of energy piles around it.
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