考虑土拱作用抗滑桩合理桩间距确定方法研究

Methods for determining rational spacing between anti-slide piles considering soil arching effects

抗滑桩等非连续支挡结构在滑坡工程中依靠土拱效应安全经济地发挥支护功能,而土拱的形成与破坏主要取决于桩间距的合理设置。首先基于抗滑桩桩间土拱已有研究成果,综合分析了土拱的拱脚位置、土拱形状以及拱轴线方程,建立了合理的土拱计算模型,然后结合桩土接触界面抗剪强度条件和土体抗剪强度条件获得了的圆形抗滑桩合理桩间距计算公式。最后,结合某工程算例,重点分析了土体内摩擦角、桩土界面参数以及桩径对桩间距的影响规律,结果表明:桩间距随上述参数的增大而增大,但当滑坡推力增大时其对桩间距的影响均会减弱。

The soil arching effect is required to ensure the adjacent pertaining or anti-sliding piles to work safely and cost-efficiently in landslide engineering. However, the formation and destruction of soil arch is mainly determined by rational arrangement of pile spacing. Firstly, based on many studies on soil arching effects of piles, the skewback position, shape and axial equations of soil arch are analyzed to establish a rational soil arching model. Then, a formula for rational spacing between circular anti-slide piles is obtained combined with shear strength conditions on pile-soil interface and soil. Finally, based on an engineering project, the effects of several parameters on the rational pile spacing are analyzed, such as internal friction angle, parameters on the pile-soil interface and pile diameter. The result shows that the spacing increases with the increase of these parameters, whilst these effects will be weakened with the increasing landslide thrust.