The long-term stability of a prestressed anchored slope might be influenced by the durability of the anchorage structure.To understand long-term stability of anchored rock slopes,the research presented herein evaluate...The long-term stability of a prestressed anchored slope might be influenced by the durability of the anchorage structure.To understand long-term stability of anchored rock slopes,the research presented herein evaluated the performance evolution of a prestressed anchored bedding slope system in a corrosive environment by model test.The corrosion process in a prestressed anchor bar was monitored in terms of its open-circuit potential(OCP),corrosion current density(CCD),and electrochemical impedance spectroscopy(EIS).The stability of the prestressed anchored slope was evaluated by monitoring changes in anchorage force and displacements.The experimental results show that prestress and oxygen could reduce the corrosion resistance of the anchor bar,and anchor bars in a chloride-rich environment are very susceptible to corrosion.Prestressed tendons in a corrosive environment suffer a loss of anchorage force,the prestress decreases rapidly after locking,and the rate thereof decreases until stabilising;in the later stage,corrosion leads to the reduction of the cross-sectional area of the steel bar which may cause the reduction in anchorage force again.Anchorage force controls the deformation and stability of the anchored slope,the prestress loss caused by later corrosion may lead to an increased rate of displacement and stability degradation of the prestressed anchored rock slope.展开更多
The evaluation of the seismic stability of high rock slopes is of vital importance to ensure the safe operation of the hydropower stations.In this paper,an equivalent pseudo-static force analysis based on the finite e...The evaluation of the seismic stability of high rock slopes is of vital importance to ensure the safe operation of the hydropower stations.In this paper,an equivalent pseudo-static force analysis based on the finite element method is developed to evaluate the seismic stability of reinforced rock slopes where the prestressed cables are modeled by the bar elements applied with nodal forces and bounded only at the anchored parts.The method is applied to analyze a high rock slope in south-west China and the optimization of cables.The stabilization effects of prestressed cables on the seismic stability of the slope are studied,the simulations of the concrete heading are discussed and the potential failure modes of the shear concrete plug are compared.Based on this,the optimization of cables is studied including the anchor spacing and inclined angles.展开更多
基金strongly supported by the National Natural Science Foundation of China(Project No.41672320 and 41877280)the National Key R&D Program of China(NO.2018YFC0407002)+3 种基金the Foreign experts Program of Hubei Province(WGZJ2020000011)the Fundamental Research Funds for Central Public Welfare Research Institutes(CKSF 2019180/YT)the Research and Transformation Project of the Changjiang River Scientific Research Institute(CKZS2017007/YT)the Innovation Team Project of the Changjiang River Scientific Research Institute(CKSF2017066/YT)。
文摘The long-term stability of a prestressed anchored slope might be influenced by the durability of the anchorage structure.To understand long-term stability of anchored rock slopes,the research presented herein evaluated the performance evolution of a prestressed anchored bedding slope system in a corrosive environment by model test.The corrosion process in a prestressed anchor bar was monitored in terms of its open-circuit potential(OCP),corrosion current density(CCD),and electrochemical impedance spectroscopy(EIS).The stability of the prestressed anchored slope was evaluated by monitoring changes in anchorage force and displacements.The experimental results show that prestress and oxygen could reduce the corrosion resistance of the anchor bar,and anchor bars in a chloride-rich environment are very susceptible to corrosion.Prestressed tendons in a corrosive environment suffer a loss of anchorage force,the prestress decreases rapidly after locking,and the rate thereof decreases until stabilising;in the later stage,corrosion leads to the reduction of the cross-sectional area of the steel bar which may cause the reduction in anchorage force again.Anchorage force controls the deformation and stability of the anchored slope,the prestress loss caused by later corrosion may lead to an increased rate of displacement and stability degradation of the prestressed anchored rock slope.
基金The authors gratefully acknowledge the supports from National Natural Science Foundation of China(Grant No.51109162)China National Twelfth Five-Year Science and Technology Supporting Programme(2011BAB08B01)Research Programme for Western China Communication(2011ZB04)and the Fundamental Research Funds for the Central Universities.
文摘The evaluation of the seismic stability of high rock slopes is of vital importance to ensure the safe operation of the hydropower stations.In this paper,an equivalent pseudo-static force analysis based on the finite element method is developed to evaluate the seismic stability of reinforced rock slopes where the prestressed cables are modeled by the bar elements applied with nodal forces and bounded only at the anchored parts.The method is applied to analyze a high rock slope in south-west China and the optimization of cables.The stabilization effects of prestressed cables on the seismic stability of the slope are studied,the simulations of the concrete heading are discussed and the potential failure modes of the shear concrete plug are compared.Based on this,the optimization of cables is studied including the anchor spacing and inclined angles.
