Stability Analysis And Reinforcement Practice Of Subgrade Retaining Wall Along River

The mountainous roads are mostly built on the mountain river.Many of the roads that were originally non-immersed are now submerged in the subgrade of the riverbed hydropower station,which not only increases the water content of the rock,but also reduces the shear strength,and the change of the reservoir water level will also change.The roadbed retaining wall is under stress,causing instability of the retaining wall,subsidence of the embankment,and cracking of the road surface.The paper takes the influence of reservoir water level change on the stability of G73 country road base retaining wall after the construction of Sanxikou Power Station on Lijiang River in Lishui as a research object.It uses field investigation,theoretical analysis and numerical simulation to carry out the change of water level in front of the wall to the roadbed retaining wall.The stability impact of the study,and the practice of grouting reinforcement of the subgrade provides a reference for the design and reinforcement of mountain roads.The main research work and conclusions are:1.Based on the investigation and analysis of roadbed diseases caused by the construction of the riverbed hydropower station on the Lishui River in Lishui,the original design is that the non-immersion roadbed and retaining wall are prone to road surface cracking,shoulder sinking,and even instability collapse after long-term immersion in the reservoir.accident.Through the numerical simulation,the stress,strain and stability development of the subgrade retaining wall during the change of the water level in front of the wall are studied.When the water level in front of the wall rises,the pressure in the subgrade increases,the effective stress decreases,the buoyancy increases,and the lateral and vertical displacements increase.The safety factor of the subgrade increases with the rise of the water level.When the water level in front of the wall drops,the retaining wall produces an outward lateral displacement.As the water level decreases,the lateral displacement increases,and the lateral deformation mode changes from translational to overturning.Subgrade settlement deformation follows the water level.The amount of decline increases nonlinearly,and the settlement deformation mainly occurs in the backfill of the wall.The safety factor of the subgrade also decreases with the decrease of the water level.3.Grouting reinforcement does not change the stress state in the retaining wall,but it can effectively improve the safety factor of the retaining wall;the safety factor of the retaining wall increases with the depth of grouting reinforcement and the influence radius of grouting.After the grouting,the shear strength of the soil increases and increases;4.The road surface vertical drilling and grouting method was used to grout the part of the 330 national road section of the bank of the Sanxikou Power Station,and the reinforcement effect was tested by the core method.