基于桩周土体位移的双排抗滑桩计算模型

CALCULATION MODEL OF DOUBLE-ROW STABILIZING PILES BASED ON DISPLACEMENT OF SOIL AROUND PILES

假设桩周土体位移沿滑坡体深度均匀分布,抗滑桩为弹性地基梁。基于单桩在桩周土体水平位移作用下的挠度解析解,通过引入桩顶连梁静力平衡条件和变形协调条件,建立桩周土体水平位移作用下的双排抗滑桩理论计算模型。在模型中,针对双排抗滑桩间普遍存在的"遮蔽效应",通过定义后排抗滑桩与前排抗滑桩桩周土体位移比进行量化考虑,并将理论模型解析过程通过Matlab编程实现,建立简化的FLAC3D有限差分程序,对理论模型计算结果进行验证。结果表明,基于桩周土体位移的双排抗滑桩理论计算模型与FLAC3D有限差分数值模型计算得到的内力基本吻合。探讨理论模型适用的桩排距范围,发现桩排距较小时,模型内力计算结果精度较高,随着桩排距的增大,理论模型与数值模型计算得到的内力误差变大。

Soil displacement around the sliding mass is assumed to be uniformly distributed along the depth of sliding mass and the stabilizing pile is assumed to be elastic foundation beam. Based on/he closed-form solution of single-row stabilizing pile under the action of lateral soil displacement around the pile, a theoretical model of double-row stabilizing piles is built by introducing static equilibrium and deformation compatibility conditions of the connecting beam. The shadow effect between double-row stabilizing piles is considered by defining ratio of soil displacement around the rear stabilizing pile to that around the front stabilizing pile. Solving process of the theoretical model is realized by writing programme in Matlab software. A simplified numerical model in FLAC3D platform is established to validate the result from theoretical model. The results show that the internal forces calculated from the numerical model and theoretical model are consistent to each other. The suitable range of the theoretical model is discussed. It is found that the result of the theoretical model is more accurate~ and the error of calculating results between the numerical and theoretical models changes larger as the distance between the front and back stabilizing piles increases.