Engineering Behaviour Of Deep-Cut Rock Slope With A Fractured Fault In Road Embankment Section

Using a method combining numerical simulation with field monitoring, the excavation stability and reinforcement effects of the slope at K132 of Xichang-Panzhihua highway were systematically and profoundly studied. The main study includes three parts as below:(1) Based on the site survey, topographical condition and geologic information achieved before excavation of the rock high-slope, the 3-D FEM model of the slope was builded using the program of ANSYS. According with the geological information obtained as construction, the 3-D model was divided into seven parts properly, and then, the mesh information of the FEM model was leaded into FLAC^3D following its format being transferred into the required vertion. After that, based on the rock mechanical experiment, the parameters of the numerical model was determined.(2) A method using 1-D elastic-plastic cable element and 3-D elastic-plastic rockbolt element respectively to couple with 3-D linear-elastic beam element was presented for simulating rockbolt frame beam, prestressed anchor cable frame beam and their interacting with rock masses. With that method, evaluation and comparison to schemes of reinforcement for slope at K132 of Xichang-Panzhihua highway was achieved. The results show that support scheme using rockbolt without frame beam is effective as the designed support scheme to modify distribution of displacement/stress in superficial layer of the slope, but it can't confine deformation at the slope surface; layout of cables and designed value of the prestress for anchor cable frame beam can obviously influent stress/displacement field of interior of the slope. So, prestressed anchor cable frame beam can be used to enhance integral stability of the rock slope.(3) During the excavation and reinforcement of the rock high-slope as construction at K132 of Xichang-Panzhihua highway, a dynamic monitoring system was used to measure its stability. Field data collected showed that, in normal conditions, the stress field of the slope body was influenced mainly by ambient temperature, and the influence range is limited. During construction, even the stretching of the anchorage cable disturbed the stress field of the slope body, the disturbance just maintained in a relatively short time. Combining with data from deep-seated displacement monitoring, it could be concluded that, as construction, the stability of the slope was influenced by the following factors: 1) artificial activities: excavation, blast and support; 2) natural disturbances: rainfall, etc, but the integral body of the slope was stable.