Study On The Stability Of Large-volume Foundation Pit Excavation And Abandoned Slag Slope Across Steep Slope Gorge Bridge

With the extension of the highway and railways to the western region,the bridges over striding the mountains and valleys are increasing rapidly.Bridges in the canyons will inevitably affect the stability of the slope on both sides of the mountain,especially the slagging problem in deep excavation of large open pit and the slope stability problem for waste dumpsite.In this paper,the stability of Jinshajiang Bridge crossing Lijiang River,the feasibility of large foundation pit excavation and reinforcing retaining wall for nearby equipment waste dumpsite are discussed.The main conclusions are summarized as follows:1.Based on the natural environment at the bridge site,the preliminary results of the stability of the bridge show that the site is suitable for the bridge construction,and reinforcement is needed in the construction process;2.Taking the stability analysis of Lijiang bank slope as an example for simulation,the results show that the original slope structure is stable and the foundation pit excavation is safe in the case of anti-slide pile.Meanwhile,it shows that if the anti-slide pile is longer than a certain depth,its effect for reinforcement will be limited.3.The failure mechanism and deformation characteristics of the slope are obtained to analyze the stability of the slope excavation by the combination of the equilibrium analysis method and the finite element model.The results show that the slope strain of the mountain slope and the anchor stress are within a reasonable range and reinforcement treatments strengthen the stability of the slope.4.Based on the analysis of the stability of the original slope of waste dumpsite,the design of the retaining wall and its simulation under the rain and earthquakes are carried out.The results show that the suitable way of discarding slag and reasonable retaining wall equipment can guarantee waste dumpsite slope stability.