页岩风化层深路堑边坡坍滑病害整治研究

Study on Slope Sliding Failure of Heavy Cut on Shale Weathering Layer

近年来,铁路风化层高边坡变形超限或失稳情况频现,为探明其致灾机理,对某重载铁路局部页岩风化层深路堑边坡坍滑病害工点的边坡变形、受力特征和致灾原因进行分析,研究该坍滑病害的发育特点、形成原因,并提出病害整治方案。研究结果表明:(1)页岩风化层深路堑边坡坍滑病害多表现为边坡桩板墙以上产生明显的滑移变形破坏,边坡平台外缘产生持续发展的纵向裂缝;(2)页岩岩质软弱,层面间易滑动,具鼓胀性,遇水易软化、抗剪强度急剧降低,极易诱发溜坍、坍滑等变形破坏病害;(3)应加强对页岩等极软岩的岩芯判识,以及加强坡脚、缓边坡、封闭或半封闭坡面的防护和防排水,并落实“分级开挖、分级防护”工序,以确保页岩等极软岩高边坡长期稳定。

In recent years,the exceeding of deformation or instability of the high slope of the railway weathered layer has been frequent.In order to find out the disaster mechanism,the slope deformation,force characteristics and disaster causes,a heavy-haul railway with partial shale weathering layer and deep cut slope landslide was analyzed.The development characteristics and causes of the slump disease were studied,and a disease remediation plan was presented.The results indicates that:(1)Slip deformation above pile-slab wall is one of main diseases of deep cut slope in shale weathering layer and a progressive longitudinal crack develop at the outer edge of the slope platform.(2)Shale is weak in quality,and easy to slide between layers.It is easy to be soften once contact with water,and its shear strength is sharply reduced.Deformation and damage diseases such as slump is induced easily.(3)It is necessary to strengthen the core identification of extremely soft rocks such as shale,and strengthen the protection and drainage of slope toe,gentle slope,closed or semiclosed slope,and implement the“graded excavation,graded protection”process to ensure high slopes of extremely soft rocks such as shale.