PORE WATER PRESSURE RESPONSE AROUND PILE AND ITS EFFECTS ON P-Y BEHAVIOR DURING SOIL LIQUEFACTION
PORE WATER PRESSURE RESPONSE AROUND PILE AND ITS EFFECTS ON P-Y BEHAVIOR DURING SOIL LIQUEFACTION
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DOI：
10.3208/sandf.44.6_101
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发表时间：
2004-12
影响因子：
3.7
通讯作者：
K. Tokimatsu;H. Suzuki
中科院分区：
文献类型：
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作者：
K. Tokimatsu;H. Suzuki
基于在可液化土壤沉积物中建造的桩结构系统进行的大型振动台试验，研究了桩周围孔隙压力响应对 P-Y 行为的影响，定义为路基反应与土壤和桩之间的相对位移之间的关系。液化过程中土体与桩之间的相对位移交替地在桩的一侧产生拉应力状态，在另一侧产生压应力状态。延伸侧孔隙压力和土压力显着下降，而受压侧孔隙压力和土压力基本保持不变或略有增加。延伸侧孔隙压力和土压力的大幅降低可能是由于延伸应力和剪应力引起的膨胀的共同作用造成的。相比之下，压缩侧孔隙压力和土压力的微小变化可能是由于压缩应力和剪应力引起的膨胀的不利影响。结果，桩的水平路基反力增大，使得桩被延伸侧的土壤拉动。这种机制与干砂中发生的机制完全不同，干砂中的水平路基反应总是由压缩侧土压力的增加引起。伸长侧土体中孔隙水压力和土压力的减少量在群桩内部比外部小。这可能是因为，在群桩内部，一侧桩引起的拉伸应力可能会被另一侧桩引起的压缩应力抵消，从而导致孔隙压力的降低不显着。
The effect of pore pressure response around a pile onp-y behavior, defined as the relation between subgrade reaction and relative displacement between soil and pile, is examined based on large shaking table tests conducted on pile-structure systems constructed in liquefiable soil deposits. Relative displacement between soil and pile during liquefaction alternatively creates extension stress state on one side and compression stress state on the other side of the pile. The pore pressure and earth pressure on the extension side decrease significantly, while those on the compression side maintain almost constant or increase slightly. The large reduction in pore pressure and earth pressure on the extension side is caused probably by the combined effect of extension stress and dilation induced by shear stress. The insignificant change in pore pressure and earth pressure on the compression side, in contrast, is probably due to the adverse effect of compression stress and dilation induced by shear stress. As a result, the horizontal subgrade reaction of the pile increases in such a way that the pile is pulled by the soil on the extension side. Such mechanism is completely different from that occurring in dry sand where horizontal subgrade reaction is always induced by the increase in earth pressure on the compression side. The reduction in pore pressure and earth pressure on the extension side becomes smaller in the soil inside than outside the pile group. This is probably because, inside the pile group, the extension stress induced by a pile on one side may be canceled by the compression stress induced by a pile on the other side, leading to an insignificant reduction in pore pressure.