群桩相互作用的近似三维弹性分析方法的建立

群桩已不再具有圆形单桩的轴对称性,因此群桩的承载特性及群桩效应不仅受桩间距的影响,而且受群桩布置方式的影响。为分析这些因素,基于Mindlin位移解,通过将桩沿桩表面进行三维剖分,建立了能够考虑群桩之间相互作用的三维分析方法,同时该方法还能够考虑长短桩、不等直径桩之间以及有无刚性承台下的群桩相互作用。与现有的方法相比,该方法能够取得较好的结果,即使群桩之间被夸大的效应减小了,桩顶荷载的分布更趋于实际工况。另外,还得到一个有益的结论:群桩中的桩身摩阻力沿桩身横截面是非均匀分布的,位于群桩内侧的桩身摩阻力小于外侧的桩身摩阻力。

Analysis for interaction of pile groups based on three-dimensional elastic theory

Unlike a single circular pile,the pile group is non-axisymmetrical.Therefore,not only the pile spacing but also the pile group layout will have influence on both the bearing capacity and the pile group effect of pile groups.In order to analyze these influential factors,a calculation method was proposed for obtaining the load-settlement relationship of the pile groups with or without a rigid cap,using the Mindlin equation and the static force equilibrium equation.Additionally the proposed method could consider piles with unequal length and diameter.Compared with the existing methods,the proposed method could obtain more reasonable results which could decrease pile group effect and render a distribution of pile head load agreeable to the fact.It was also founded that the distribution of friction around pile section was unequal,and the friction on the internal piles was larger than that on the external piles of the group.