为探究考虑扰动效应时透水管桩桩周土的固结特性,利用有限元分析软件,建立了考虑扰动效应的饱和软黏土中透水管桩地基土固结三维模型,然后采用模型退化及试验实测数据对比两种方式进行有限元模拟准确性的验证。最后,在考虑扰动效应影响下,对不同开孔几何参数下桩周土超静孔压的消散情况进行了讨论。结果表明:模型退化验证及对比实测数据均与数值模拟结果基本保持一致,很好地验证了数值模拟的准确性;扰动程度系数α的变化仅对超静孔压前期的消散速率影响显著,并造成一定程度的孔压消散差,随着孔压消散的进行这一差距逐渐减小。扰动范围s的增大对于孔压消散速度的影响并不明显,相对于扰动范围s,桩侧孔压的消散速度对于扰动程度系数α的变化更敏感;不同开孔几何参数下的桩周土超静孔压随时间、空间的变化规律均表明了扰动效应对超静孔压消散速度具有显著影响。研究成果对于实际工程中透水管桩地基固结分析具有一定参考价值。
Abstract
A 3D consolidation model of saturated soft clay around permeable single pile is established by using finite element software to analyze the consolidation behaviors of soil foundation of permeable pipe pile in consideration of disturbance effect. The accuracy of the finite element model is verified through model degradation and test measurement. Furthermore, the laws of dissipation of excess pore water pressure with different geometric parameters of permeable pile are discussed under disturbance effect. Results manifest the accuracy of the finite element model with the simulated result consistent with model degradation and test measurement. The disturbance intensity coefficient α can significantly affect the dissipation rate of excess pore water pressure at the early stage, resulting in the differences of dissipation rate of excess pore water pressure, which, however, reduces along with the dissipation process. The increase of disturbance region s has no significant effect on the dissipation of excess pore pressure, which is more sensitive to disturbance intensity coefficient α. The laws of the dissipation of excess pore water pressure related to different geometric parameters of permeable pipe pile all imply a significant impact of disturbance on the dissipation speed.
关键词
透水管桩 /
扰动效应 /
地基土固结 /
有限元分析 /
孔压消散速度
Key words
permeable pipe pile /
disturbance effect /
consolidation of soil foundation /
finite elements analysis /
velocity of pore pressure dissipation
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基金
国家自然科学基金项目(51878185);广西自然科学基金创新研究团队项目(2016GXNSFGA380008);八桂学者项目(2016A31)
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