Evaluation of potential failure of rock slope at the left abutment of Jinsha River Bridge by model test and numerical method

Jinsha River Bridge is located on Tiger Leaping Gorge town, China. The left bank slope composes of moderately thick layer of slate overlain by schistose basalt, and where rocks are controlled by two sets of joint planes. To evaluate the stability of the rock slope under bridge foundation, model test and calculation model based on the geological parameters and the slope stability was simulated and analyzed using Universal Distinct Element Code (UDEC) and Finite Element Mehod (FEM). According to model test, failure mainly initiated at the toe with shear movement along the joint planes, eventually resulting in the sliding along the slope surface and formation of tension crack at the crest of the model. This result coincide with the UDEC model, which shows that slope surface will produce loosening damage and slipping expected along the joint planes under different loading conditions. Moreover, the result of FEM analysis indicates that the rock mass under the main pier has potential shear failure region. So, the bridge foundation should be strengthened to prevent the slope failure under external forces.