兰永一级公路顺层滑坡抗剪强度参数确定及应用

Determination and application of shear strength parameters of bedding landslide of Lanzou-Yongjing Highway

兰永一级公路工程修建过程中在路堑边坡开挖时形成了顺层边坡,以K23+520处的大型顺层滑坡最为典型。由于岩土体抗剪强度参数在边坡稳定性分析和加固设计中不可或缺,为了更好地实现其余类似边坡的加固设计和稳定性分析,以K23+520处的滑坡为研究对象,提出含有软弱夹层的顺层滑坡结构面上抗剪强度参数的确定方法:对已知一个滑动面位置的滑移–拉裂破坏模式下的顺层滑坡,通过结合顺层滑坡失稳条件(临界高度、局部稳定系数)及变形破坏特征对满足刚体滑移模型下的多组强度参数进行逐步修正,得到了满足工程应用要求的强度参数取值,并将结果用于类似边坡的加固设计和稳定分析。方法不仅适合兰永一级公路K23+520处顺层滑坡结构面上抗剪强度参数的确定,还适用于类似滑坡工程强度参数的确定,具有一定的工程实用价值。

Bedding slope is formed in the excavation of cutting slope during construction of Lanzhou-Yongjing Highway, with K23+520 large bedding landslide being the most typical. Due to the importance of shear strength parameters of rock and soil in the slope stability and support design, in order to better realize the reinforcement design and stability analysis of similar slopes, taking K23+520 section of landslide as the research object, a method is put forward to determine the shear strength parameters of slip surface of bedding landslide with weak interlayer: for the landslide with a given location of slip surface, the failure conditions of the bedding landslide(critical height, local stability coefficient) and the deformation characteristic are combined to revise muttiple groups of strength shear parameters to meet the rigid sliding model step by step, the strength parameters satisfying the requirements of engineering application are obtained, and the results are used for the reinforcement design and stability analysis of similar slopes. This method is suitable for determining the strength parameters of the structural plane of K23+520 bedding landslide of Lanzhou-Yongjing Highway and other similar landslides, and it has a certain practical value in engineering.