Study On The Stability Of Reinforced Arch Bridge Abutment Slope With Prestressed Anchor Cable Frame Beam

Based on the foundation project of a super large bridge in southwest mountainous area of China.The soil behind the arch abutment of the bridge foundation is located in the strong weathering layer.Under the action of horizontal component force,the compression amount is large and the horizontal displacement exceeds the limit.It is not only difficult to provide sufficient horizontal thrust,but also has a great influence on the stability of the rock slope behind the arch abutment.Therefore,it is proposed to use prestressed anchor cable frame beam to reinforce the bridge foundation slope.This paper studies the anchoring effect of prestressed anchor cable frame beam on bridge foundation slope under different working conditions under specific engineering background.In this paper,the pull-out effect of single anchor cable is studied from two aspects of different overlying load and different anchorage angle through indoor pull-out test.FLAC3 D finite difference software is used to simulate the anchoring effect of prestressed anchor cable frame beam on bridge foundation slope under different anchoring conditions(different anchoring angles,anchoring length and anchoring spacing).The main contents of this paper are :(1)Read the literature to understand the application and research methods of rock and soil anchoring technology.Summarize the application and research methods of rock and soil anchoring technology from theoretical research,experimental research and numerical simulation research.(2)Formulate relevant indoor drawing test plan.Based on the test purpose,the model box,model soil,anchor cable,loading system and measurement system are designed and manufactured.The mechanical parameters of the model material were determined by laboratory tests.(3)According to the predetermined test plan,this pull-out test studies the influence of different overlying loads and different anchorage angles on the pull-out resistance of anchor cables.Through comparative analysis,it is known that the improvement of the overlying load has a significant effect on the improvement of the pulling resistance of the anchor cable.The ultimate pull-out resistance of anchor cable anchorage section increases first and then decreases with the increase of anchorage angle.Under the condition of this test,the optimal anchorage angle of anchor cable is 40°.(4)Using FLAC3 D software for numerical calculation,simulation analysis of different anchorage angle,different anchorage length,different anchorage spacing under different conditions of anchor cable frame beam reinforcement for bridge foundation slope stability,plastic zone distribution,vertical The influence of displacement and horizontal displacement.The anchorage parameters are evaluated from the aspects of economy,safety factor improvement and deformation reduction.The optimal anchorage angle is 40°,the optimal anchorage spacing is 3m,and the optimal anchorage length is 4m.The optimal anchoring angle obtained is consistent with the indoor pull-out test results,which verifies the correctness of the model.