群桩加筋效应机理研究

把Poulos的弹性理论法推广到对群桩进行整体分析，群桩中每根桩的形状和荷载可以互不相同．对2根桩的分析表明，受荷桩使其邻桩的桩身产生了附加轴应力及附加剪应力，桩对土的加筋效应就是通过附加剪应力发生的．对群桩的分析表明，其他桩的加筋效应使受荷桩的沉降产生了折减，当桩土模量比和桩间距较小时，忽略桩的加筋效应会对群桩分析带来很大的误差．对群桩内的应力分布分析表明，与单桩相比，由于桩的加筋效应，使得群桩能够把较多的荷载直接传递到桩端平面．

Study on reinforcing effect of grouped piles

The elastic theory method developed by Poulos is extended to the global analysis of grouped piles. The analysis of two piles shows that the loaded pile induces additional axial stress and shear stress along the shaft of the unloaded pile. The reinforcing effect of piles is caused by the additional shear stress. The analysis of grouped piles shows that the settlement of one pile in grouped piles is smaller than that of a single isolated pile with equal loading as a result of reinforcing effect of other piles. So the reinforcing effect of piles cannot be ignored. The analysis of stress distribution in grouped piles shows that the increasing proportion of the load transmitted at the base of grouped piles stems also from the reinforcing effect of piles.