Consolidation analysis of composite ground improved by granular piles with a high replacement ratio considering overlapping smear zones
Consolidation analysis of composite ground improved by granular piles with a high replacement ratio considering overlapping smear zones
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DOI：
10.1016/j.compgeo.2023.105636
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发表时间：
2023-10
影响因子：
5.3
通讯作者：
Weitao Yang;P. Ni;Zheng Chen;Jianxue Feng;Guo Mei
中科院分区：
文献类型：
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作者：
Weitao Yang;P. Ni;Zheng Chen;Jianxue Feng;Guo Mei
建立了高置换率碎石桩复合地基的数学模型，考虑了复合地基的涂抹区重叠、桩体水平和竖向渗透系数以及地基中随时间和深度变化的堆载应力。随后，解的超孔隙水压力，沉降和固结度的复合地基解析推导出使用有限正弦傅立叶变换。通过与退化情况和有限差分法数值结果的比较，对解的正确性进行了评估。通过参数试验，研究了加载时间、桩体径向渗透系数、重叠涂抹区等参数对地基固结速率和超静孔隙水压力消散过程的影响。结果表明，复合地基中桩体间存在重叠的涂抹区和较小的桩体径向水阻力会降低复合地基的固结速率。通过数值分析，探讨了不同条件下桩的最佳布置间距。在综合考虑加快地基固结速率和减小地基总沉降的基础上，提出了优化桩间距的参考值，可供设计参考。
A mathematical model for composite ground improved with granular piles with a high replacement ratio is presented, accounting for the overlapping smear zones, horizontal and vertical permeability coefficients of piles, and time- and depth- dependent surcharge stress in the foundation. Subsequently, solutions for excess pore-water pressure, settlement, and consolidation degree of composite ground are derived analytically using the finite sine Fourier transform. The correctness of the solutions is assessed by comparing with the degenerated cases and numerical results obtained by the finite difference method. Parametric studies are conducted to explore the influence of parameters, such as the loading time, radial permeability coefficient of piles, and overlapping smear zones on the consolidation rate of the foundation and the dissipation process of excess pore-water pressure. Results show that the overlapping smear zones and smaller radial hydraulic resistance of piles can slow down the consolidation rate of composite ground. Furthermore, the optimal layout spacing of piles under different conditions is discussed through numerical analyses. Based on a comprehensive consideration of accelerating the consolidation rate and reducing the total foundation settlement, this investigation provides some reference values of the optimal pile spacing for use in design.