梯形抗滑桩截面尺寸对土拱效应的影响

近年来,土拱性状对于抗滑桩的设计及布设有着重要意义,土拱的高度会直接受到抗滑桩的截面尺寸及桩间净距的影响,考虑到抗滑桩的抗滑力是由桩背及桩侧两部分共同提供,故提出在矩形桩的基础之上,不改变原桩背尺寸的前提下,提高桩侧的抗滑性能可以促使桩后土拱与桩侧土拱的协同发展,梯形抗滑桩恰如其分。本文通过FLAC-3d及力学计算相结合的方法探究了梯形抗滑桩的截面尺寸对于土拱高度的影响性。保持桩背尺寸不变的前提下,改变抗滑桩下底尺寸,实现了从矩形桩到梯形桩的变化以及提供了桩侧倾角的变化。结果表明,随底边尺寸的增大,土拱发育,且桩侧土拱的发育更加明显,拱高于截面上下底边比值从0.4到0.65之间增大,截面上下底边比值从0.65到0.85之间间土拱高度减小。此外,证实了通过改变截面形式,截面上下底边比值从0.5到0.65之间可促进桩背土拱与桩侧土拱协同作用,从而充分发挥梯形抗滑桩的受力性能。

In recent years,the characteristics of soil arches are of great significance for the design and layout of anti-slide piles.The height of soil arches is directly affected by the cross-section dimensions of anti-slide piles and the clearance between piles,considering the anti-sliding force of anti-slide piles.It is provided by the two parts of the pile back and the pile side.Therefore,on the basis of the rectangular pile,without changing the size of the original pile back,improving the anti-sliding performance of the pile side can promote the soil arch behind the pile and the soil arch on the pile side.The synergistic development of the trapezoidal anti-slide pile is just right.In this paper,the influence of the cross-sectional dimension of the trapezoidal anti-slide pile on the height of the soil arch is explored by the combination of FLAC-3d and mechanical calculation.Under the premise of keeping the pile back size unchanged,the size of the bottom of the anti-slide pile is changed,and the change from the rectangular pile to the trapezoidal pile is realized and the variation of the pile roll angle is provided.The results show that with the increase of the bottom edge size,the soil arch develops,and the development of the soil arch on the pile side is more obvious.The ratio of the arch above the upper and lower sides of the section increases from 0.4 to 0.65,and the ratio of the upper and lower sides of the section is from 0.65 to The height of the soil arch is reduced between 0.85.In addition,it is proved that by changing the section form,the ratio of the upper and lower bottom edges of the section from 0.5 to 0.65 can promote the synergy between the pile back soil arch and the pile side soil arch,so as to give full play to the force performance of the trapezoidal anti-slide pile.