论文部分内容阅读
南京～杭州(宁杭)高速公路(江苏段)线路近南北向穿越宜兴市兰右山。兰右山山体走向近东西向, 为剥蚀低缓丘陵。深路堑西侧边坡最大挖深约40m,设计边坡为台阶式,每级边坡高度为8m。该段路堑边坡主要 为岩质边坡,其主要岩组为泥盆系五通组石英砂岩夹泥岩,岩石强度一般较高,岩层产状平缓,具中～厚层结构类 型。西侧边坡泥岩层面稍内倾。在分析深路堑工程地质特征、边坡稳定性影响因素及边坡变形破坏机理的基础上指 出:该段西侧高边坡一级台阶为泥岩,二级以上台阶为石英砂岩,边坡呈“上硬下软”双层结构。由于泥岩岩性特殊, 具有浸水软化、膨胀、崩解、易风化等特征,在地下水诱因下,这种双层结构类型对边坡稳定性十分不利。为了保证 高速公路运营安全,宜采取主动防护措施,如坡面封闭隔水处理、预应力锚索、砂浆锚杆框架等防护方案,以防止发 生边坡深层破坏。
Nanjing ~ Hangzhou (Nanjing-Hangzhou) Expressway (Jiangsu section) line near the north-south through the Yilan Lan You. Lan You Shan toward the east-west mountain, denuded low hills. The maximum excavation depth of the west side slope of deep cut is about 40m. The designed slope is step-type, and the slope height of each grade is 8m. This section of the cutting slope is mainly of rock slope, the main rock group is Devonian Wutong quartz sandstone mudstone, the rock strength is generally high, rock formation is gentle, with medium ~ thick structure type. West side slope of mudstone slightly lean. Based on the analysis of the engineering geological characteristics of deep-cutting engineering, the influencing factors of slope stability and the deformation and failure mechanism of slope, it is pointed out that the first step of the high slope on the west side of the section is mudstone, the second stage and above are quartz sandstone, On the soft under the "double structure. Because of the special lithology of mudstone, which has the characteristics of softening, swelling, disintegration, weathering and so on, this type of double-layer structure is very unfavorable to slope stability under the groundwater inducement. In order to ensure the safety of expressway operation, active protective measures should be taken, such as closed slope water treatment, prestressed anchor cable, mortar anchor frame and other protection programs to prevent the occurrence of deep slope damage.