膨胀岩渠坡的变形破坏特点与稳定分析

在南水北调中线工程中,膨胀岩渠坡处理是总干渠的关键技术问题之一,现以潞王坟试验段滑坡为例,对膨胀岩的破坏模式进行了分析总结,指出膨胀岩渠坡受胀缩特性的影响普遍具有浅层性、渐近性、牵引性,同一位置多次滑动的特点。膨胀岩渠坡的稳定与岩性组合、地质构造、膨胀潜势等级等自然因素有关外,与开挖的边坡高度、边坡走向、岩体含水率的变化、卸荷后裂隙开展等边界条件密切相关,不利的组合为渠道边坡滑动创造了空间地质环境。对裸坡区的破坏进行模拟计算时,是否采用按大气影响带进行参数取值以及施加膨胀力等边界条件的设定,对膨胀岩渠坡稳定计算方法进行了探讨,为工程建设领域同类条件下的分析计算提供参考。

Characteristics of Deformation Damage and Stability Analysis of Swelling Rock Slope

The treatment of swelling rock slope is one of the key technological problems in the main channels of the south-to-north water diversion project.This paper summarized the failure modes of the swelling rock based on the landslides at the Luwangfen testing section,and pointed out that the swelling rock slope is generally shallow,gradual,tractive and has multiple slides at the same location due to the effects of swelling and shrinkage.The stability of the swelling rock slope depends on not only the natural factors including the lithologic association,geological structure,and expansive potentiality,but also the boundary conditions including the height and direction of the slide slope,variation of the rock moisture content,and the expansion of the fractures after unloading.Therefore,the combination of the above factors may contribute to the slide of the rock slope.The damages on the bare slope were simulated,and the parameters and boundary conditions were based on whether the atmospheric influence should be considered,which proposed the discussion of the calculation method for the stability of the swelling rock slope.The method can provide references for the similar conditions in the engineering construction.