An analytical solution for the consolidation around a driven pile
An analytical solution for the consolidation around a driven pile
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DOI：
10.1002/nag.1610030302
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发表时间：
1979-07
影响因子：
4
通讯作者：
M. Randolph;C. Wroth
中科院分区：
文献类型：
--
作者：
M. Randolph;C. Wroth
现场研究表明，在粘性土中打入置换桩会在桩附近产生较大的超静孔隙水压力。这些孔隙压力通常大于有效上覆岩层压力，便于桩的安装。桩承载力的增加主要是由超孔隙压力的消散和作用在桩上的有效应力的增加所控制。本文在假定桩周土骨架发生弹性变形的条件下，给出了打入桩周土径向固结的解析解。根据预测的土壤中的有效应力变化，这一假设进行了检查，并显示导致，一个现实的模型，桩附近的孔隙压力随时间的衰减后驾驶。虽然该解可适用于任何初始超静孔压分布，但注意力主要集中在理想弹性、理想塑性土中圆柱形孔扩张引起的超静孔压分布。由此产生的超孔隙水压力随半径的对数变化被认为是接近的桩周围产生的驱动的结果。除了估计打入桩达到最大强度所需的时间外，该解决方案还可用于压力计试验的分析，以提供土壤固结系数的现场测量。
Field studies have shown that the driving of a displacement pile into cohesive soil generates large excess pore pressures in the vicinity of the pile. These pore pressures are often larger than the effective overburden pressure and facilitate the installation of the pile. The subsequent increase in bearing capacity of the pile is largely controlled by the dissipation of the excess pore pressures and a consequent increase in the effective stresses acting on the pile. The paper presents a closed formanalytical solution for the radial consolidation of the soil around a driven pile, assuming that the soil skeleton deforms elastically. This assumption is examined in the light of the predicted effective stress changes in the soil and is shown to lead to, a realistic model for the decay of pore pressure near the pile with time after driving. Although the solution may be applied to any initial distribution of excess pore pressure, attention is focussed on that due to the expansion of a cylindrical cavity in an ideal elastic, perfectly plastic soil. The resulting logarithmic variation of excess pore pressure with radius is considered to be close to that generated around a pile as a result of driving. In addition to giving estimates of the time needed for a driven pile to achieve its maximum strength, the solution may also be used in the analysis of pressuremeter tests to provide in-situ measurements of the coefficient of consolidation of the soil.