基于颗粒流的抗滑桩土拱效应研究

Soil arching effect of anti-slide piles based on particle flow method

抗滑桩土拱效应的研究目前主要是建立在连续介质理论基础上,难以考虑土体颗粒粒度组成等重要影响因素,因此有必要进一步深入揭示土体这种非连续、非均匀散粒体的成拱机理。利用颗粒流方法,研究了抗滑桩截面大小、间距、桩土相对变形速度和土体颗粒粒度组成对土拱效应的形成、发展、破坏和再形成过程的影响,并揭示了这些因素对土拱的极限承载能力、残余承载能力和桩土荷载分担比的影响规律。结果表明:以上因素对抗滑桩土拱效应影响显著。土拱的极限承载能力随桩间距与桩宽的相对比例增大而减小,随桩土间的相对运动速度和土颗粒的分布宽度增大而增大;残余承载能力和桩体荷载分担比随桩间距与桩宽的相对比例和土颗粒的分布宽度增大而减小,随桩土间的相对运动速度增大而增大。因此在抗滑桩设计及布桩位置选择时,应尽可能考虑相关影响因素,以优化设计,节省投资。

The studies on soil arching effect of anti-slide piles are mainly based on the continuous medium theory at present.It is difficult to consider the distribution of soil particle size and other important factors.It is necessary to further reveal the arching mechanism of soil which is non-continuous and non-uniform material.Particle flow code（PFC） is used to study the effects of anti-slide pile size,spacing,pile-soil relative deformation rate and soil particle size distribution on the formation,development,destruction and re-formation process of the soil arch.The effects of the above factors on the maximum bearing capacity,residual bearing capacity of the soil arch and the pile-soil load share ratio are revealed.The results show that the effects of these factors are significant.The maximum bearing capacity of the soil arch decreases with the increase of the ratio of the pile spacing to the width and increases with the increase of pile-soil relative deformation velocity and soil particle distribution width.The residual bearing capacity and the pile load distribution ratio decrease with the increase of the relative ratio of the pile spacing to the width and soil particle distribution width,and increase with the increase of pile-soil relative deformation velocity.Therefore,the design and location of anti-slide piles should consider relevant factors as many as possible to optimize the design and save investment.