Research On Stability Assessment Of Tunnel Rock Slope Across Dali-Ruili Railway In Section Of Mount Gaoligong

Along the new built Dali-Ruili railway, which has the whole length of 350km, there are most mounts and gorges. And many tunnels and bridges need to be excavated and built when the railway across these areas. In that case, the 75 percent of the whole length of the railway are tunnels and bridges. Complicated geological environment of Mount Gaoligong servants region will have extreme influence on stability of rock mass,which leads to some security problems of railway tunnel engineering slope on both sides, therefore, it has great theoretical significance and practical value to study the rock mass structure and stability of cross-strait engineering slope deeply and systematically.Based on the left bank of the four foundation slope (Lanzhao River bridge,Mayi River bridge, Naobai River bridge, Zaotang river bridge) as the research object, engineering suitability of rockmass in canyon area has been evaluated systematically to give a better guide to slope protection engineering. Using discrete element numerical simulation software, deformation and failure mode of the slope can be analyzed under seismic load, and combined with Newmark method, comprehensive evaluation of slope stability has been achieved.This paper has following main reserch contents and results:1. The research of engineering geological environmental conditions: including natural geographical conditions, topography and geomorphology, structure and geological conditions, and the engineering geological conditions in bridge area.2. Through indoor experiment such as the field experiment (spot rebound hammer test) and field sampling means, the rock and the structure of the strength of rock characteristics have been found out, such as heavy, compressive strength, the shear strength, tensile strength and elastic modulus, the structure of the shear strength etc, which provides basis for the stability of the slope evaluation.3. Using 2d discrete element (UDEC) , deformation response laws on each slope have been analyzed and predicted under seismic load.4. Based on the Newmark method, slope stability has been evaluated using SLOPE/W and QUAKE/W in Geo-Studio software.5. Based on the same seismic waves inputing, acceleration of every designated height of slope has been monitored, and it summarizes the acceleration amplification coefficient variation rules with height.