雷华阳, 吕乾乾, 刘利霞. 2012: 考虑超静孔隙水压力消散的管桩承载力时效性研究. 工程地质学报, 20(5): 815-820.
    引用本文: 雷华阳, 吕乾乾, 刘利霞. 2012: 考虑超静孔隙水压力消散的管桩承载力时效性研究. 工程地质学报, 20(5): 815-820.
    LEI Huayang, LV Qianqian, LIU Lixia. 2012: GROWTH OF PILE BEARING CAPACITY OVER TIME CONSIDERING THE DISSIPATING OF EXCESS PORE PRESSURE. JOURNAL OF ENGINEERING GEOLOGY, 20(5): 815-820.
    Citation: LEI Huayang, LV Qianqian, LIU Lixia. 2012: GROWTH OF PILE BEARING CAPACITY OVER TIME CONSIDERING THE DISSIPATING OF EXCESS PORE PRESSURE. JOURNAL OF ENGINEERING GEOLOGY, 20(5): 815-820.

    考虑超静孔隙水压力消散的管桩承载力时效性研究

    GROWTH OF PILE BEARING CAPACITY OVER TIME CONSIDERING THE DISSIPATING OF EXCESS PORE PRESSURE

    • 摘要: 沉桩引起的超静孔隙水压力消散是产生管桩极限承载力时效性的主要因素之一。结合天津东疆保税港区物流加工区二期工程,利用有限元模拟分析沉桩后超孔压的消散规律及管桩的极限承载力随时间变化的规律,提出吹填土中管桩时效承载力公式供工程参考使用,并进行吹填土现场各测点沉桩过程及沉桩后孔隙水压力的监测,验证模拟结果的同时探讨超静孔隙水压力的分布及消散规律。模拟得到沉桩后桩底超孔压随时间消散, 20d后消散率达到97%; 管桩的时效承载力随时间增长,并与超孔压的消散有着明显的对应关系; 得到吹填土中管桩承载力的时效公式以供工程参考使用。现场孔压监测表明深度增加,超孔压增大; 离桩越近,超孔压越大; 土层渗透系数越小,超孔压消散越慢。施工对土体的有效影响范围为9~10倍桩径。

       

      Abstract: The dissipating of excess pore pressure caused by pile sinking is one of the main factors result in time effect of ultimate bearing capacity of pile. This paper discusses the change rule of pile bearing capacity with time through the finite element simulation under the geological conditions of the pile foundation in the second phase project of the free port logistics processing zone in Dongjiang, Tianjin. It finds that the formula of pile bearing capacity about time effect in dredge fill can be used as reference for engineering use. It monitors the excess pore pressure at each observing point in order to verify the numerical simulation results. It discusses the change law of the distribution and dissipation of excess pore water pressure. Numerical simulation shows that the dissipation rate at the tip of pile can reach 97% 20d after pile sinking. The ultimate bearing capacity of pipe pile increases over time basically in accord with the dissipation of excess pore water pressure. It also introduces a formula of pile aging bearing capacity in dredge fill. Measured results show that the effective range of construction on dredger fill around the pile is 9-10 times the diameter of pile. The excess pore pressure increases with the depth increasing. The closer it from the pile, the greater the excess pore pressure is. The smaller the permeability coefficient of soil is,the more slowly the excess pore pressure dissipates.

       

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