Research On Stability Analysis And Treatment Scheme Of Rock Slope With Weak Interlayer

Landslide disasters in my country are particularly serious,and the economic losses caused by landslide disasters are huge every year.In landslide treatment projects,often due to insufficient understanding of the causes and mechanisms of landslide formation,the later treatment design fails.This thesis takes a highway slope landslide as the engineering background to study the stability and treatment plan of rock slope under the condition of weak interlayer.The main research contents and results are as follows:(1)Based on the finite element strength reduction method,by co MParing the deformation,stress,and safety factor of the slope in various working conditions,the factors affecting the stability of the landslide are studied.The results show that the existence of the weak interlayer has the greatest i MPact on the stability of the slope.The safety factor of the slope is greatly reduced;when the rock and soil parameters change,the weight of the sliding body,the cohesion of the sliding surface and the change of the internal friction angle have a great influence on the stability of the landslide,and the change of the elastic modulus of the slope has a great influence on the stability of the landslide.Sexual i MPact is small.Heavy rain conditions and the excavation of the slope toe will reduce the stability of the slope to a certain extent,while the i MPact of the road load on the top of the slope is relatively small.(2)Based on the finite element strength reduction method,by co MParing the deformation,stress and safety factor of the slope under various working conditions,and verifying with monitoring measurement data,the emergency rescue effect of closed cracks and back pressure backfill in the landslide treatment process is studied.The results show: After the cracks are closed and backfilled with back pressure,the safety factor of each section slope is greatly improved.At the same time,the displacement rate of the crack monitoring point is significantly reduced after the backfilling back pressure construction is completed,and the displacement rate and displacement amount of the deformation monitoring point are significantly changed Small,the displacement curve of each deformation monitoring point tends to be stable.(3)Establish a three-dimensional numerical model based on the slope body after emergency rescue,numerically simulate the construction process of the anchored pile-slab wall,analyze the landslide treatment effect,and optimize the pile spacing and pile anchorage depth of the anti-slide pile: The length of the cantilever end of the sliding pile remains unchanged,and the anchoring length can be 8.5m～10.5m,that is,0.37L～0.42 L.Within this range,the displacement of the anti-slide pile and the internal force change greatly;when the length of the anchoring section of the anti-slide pile is10.5 When m,the pile spacing should not be greater than 5m.When the pile spacing exceeds 5m,the deformation of the free section and the lower part of the pile body will increase to a greater extent.(4)Summarize the displacement and stress characteristics of the slope body,as well as the deformation and stress characteristics of the anchored pile-slab wall during the landslide treatment process:(1)After the traffic on the top of the slope is restored,the backfill soil behind the pile and the pile at the foot of the slope The displacement of the rock-soil mass is relatively large,and the plastic zone is concentrated in the weak interlayer and the slope toe.(2)The anti-slide pile has a large displacement at the position 10.5m-12 m from the top of the pile,that is,the range from the boundary of the sandstone and mudstone layer to the toe of the slope.The displacement of the retaining plate in the range of 8-10 m from the top of the pile is large.The axial pressure on the anchor section of the anti-slide pile is relatively large,the maximum value is in the middle of the anchor section,and the pile body shear force is larger at the weak interlayer.The bending moment diagram of the anti-slide pile is symmetrically distributed along the pile body,and the bending moment of the free section Larger.