堆积层滑坡中桩-拱抗滑支护体系的稳定性分析

Stability Analysis of Pile and Srch Anti Slide Support System in Accumulation Layer Landslide

浅层堆积层滑坡在我国各类地质滑坡灾害中所占比例较高,研究该层滑坡加固技术对防灾存在重要实际意义。文中提出对堆积层滑坡采用桩-拱抗滑支护体系进行加固,分析该支护体系稳定性。在滑坡推力作用下土体受压变形,形成抗滑桩间土拱效应,通过分析其形成机理可知桩利用抗剪强度及土体间应力分布抵抗滑坡推力,并研究拱脚、拱轴线等与土拱效应关系,以三铰拱原理为基础,运用合理拱轴线方程描述桩-拱抗滑支护结构受力变形过程。根据相似理论制备微型桩加固滑坡模型,分别在滑坡面微型桩前方深度不同位置布置土压力盒,获得滑坡形成过程中土压力值变化结果,并对土拱效应进行分析。实验结果显示:降雨时期土拱效应程度弱;土层加深,桩前土拱压力增加;桩间距变大,则桩前土拱效应减小,且桩间最佳距离为8 d。

The proportion of the shallow layer landslide is high in all kinds of geological landslides in China. It is of great practical significance to study the reinforcement technology of this layer for preventing the disaster. In this paper,the pile-arch anti slide support system is adopted to reinforce the pile-layer landslide,and the stability of the supporting system is analyzed. Soil deformation in the compression effect of landslide thrust,anti slide forming the soil arching effect,through the analysis of the formation mechanism of the pile using shear strength and soil stress distribution of landslide thrust and resistance,arch foot,arch axis and relationship with soil arching effect,based on the principle of reasonable use of three hinged arch. The arch axis equation describing the anti slide pile arch supporting structure deformation. According to the similarity theory,the micro pile reinforcement landslide model is made. The earth pressure box is placed at different locations in front of the micro pile on the landslide surface,and the results of earth pressure change in the process of landslide formation are obtained,and the soilarching effect is analyzed. The experimental results show that: the soil arching effect is weak during the rainfall period; the soil depth is deeper,the soil arching pressure increases before pile,and the pile spacing increases,so the soil arching effect before pile decreases,and the best distance between piles is 8 d.