Study On The Performance Of Unbonded Pre-stressed Reinforced Earth Retaining Wall

The core of unbonded prestressed reinforced earth technology is to prestressing the tendons so that the lateral pressure plate,prestressed tendons and wall panels forms a system,thus constraining the backfill and improving the overall performance of the reinforced earth structure.In this paper,the performance of the retaining wall under the action of static forces and seismic waves of unbonded prestressed reinforced earth retaining walls is studied by using a combination of model tests and numerical simulations.In static analysis,the effects of pre-tension level,packing compaction degree,axial stiffness of prestressed tendons,stiffness of wall base panel,loading position,load size on the deformation performance of retaining wall were studied.In dynamic analysis,the effects of peak acceleration,pretension level,axial stiffness and length of prestressed tendons on the lateral displacement of the retaining wall,root mean square of velocity and root mean square acceleration,and axial force were studied.The following research results were obtained:(1)The pretension of the prestressed tendons can improve the integrity of the reinforced zone;After the prestressing force is applied to the tendons,the displacement of the wall panel,the settlement at the top of the retaining wall and the reaction force of the wall panel under the surcharge load are all significantly reduced compared with the case where no pretension is applied.(2)With the increase of the degree of compaction of the bakcfill,the lateral displacement of the wall,the average settlement of the position of the load,and the foundation settlement of the wall panel are all significantly reduced.As the distance from the edge of the load to the wall panel decreases,the lateral displacement of the wall and the settlement of the load increase,and the maximum lateral displacement shifts from the middle of the wall to the top.Increasing the pretension level,the axial stiffness,and the stiffness of the base of the wall panel all contribute to the reduction of the lateral displacement of the retaining wall.(3)Applying pretension to tendons helps to reduce the lateral displacement of the retaining wall under seismic waves,and the axial force of prestressed tendons increases during the action of seismic waves.The axial force of prestressed tendons increases continuously during the action of seismic waves.With the increase of the peak acceleration,the lateral displacement of the retaining wall,the root mean square of acceleration(RMSA),root mean square of velocity(RMSV),and axial force all increased significantly.Increasing the pretensioning force and axial stiffness of the tendons can reduce the lateral displacement of the retaining wall,but they have little effect on RMSA and RMSV;With the increase of the length of the prestressed tendons,the lateral displacement of the retaining wall,the RMSA and RMSV decrease.In all the cases analyzed,the RMSA and RMSV along the wall height show similar distribution rules.