Study On The Mechanical Behavior Of Anchorage System Of The Suspension Bridge

The steel anchorage system of suspension bridge consists of three parts,anchor Rod,anchor beam and anchor bracket.The anchor rod and the anchor beam are the main force-bearing components in the Anchorage system,and the anchor bracket is only used to support the anchor rod and the anchor beam and locate in the construction process.The main function of anchorage system is to disperse the main tension force that comes from the cable into the anchor body.However,in the application of the steel anchorage system,the load of the structure is quite large,even if the tension force is dispersed through the anchorage system,and the anchor body may still have serious a cracking phenomenon.The anchorage system as an important supporting part of a suspension bridge is related to the safety problem and durability of the bridges as a whole,so it is of great significance to explore the real reasons of the failure of the anchor body and find the corresponding solution.Based on the science and technology project of traffic construction in the western area and the anchorage system of the second bridge of Dongting Lake,the whole model analysis and local model analysis of the anchorage system are carried out.The main research work is as follows:(1)This paper expounds the classification and selection methods of anchorage system of the suspension bridge and sums up the current research situation about the theory and experiment of the steel anchorage system.(2)By establishing the whole model of anchorage and anchorage system,the stress distribution of anchorage under the action of self-weight and tension force is analyzed,and the most disadvantageous position of the structure is discussed.According to the existing specifications,5 possible shear surfaces are assumed in the whole model,and the stress state of the structure on the shear surface is analyzed.The overall safety problem of the structure under the assumption of the complete destruction of the shear surfaces is considered.(3)According to the analysis results of the whole model,a local model test of the anchorage beam and the concrete body around the anchor beam is designed,and the corresponding local finite element analysis model is established.The purpose of this experiment is to verify the correctness of the corresponding hypotheses and revise the finite element model.(4)Describe the possible failure modes of anchorage structure of the suspension bridge.The parametric analysis of the local model is conducted,considering the influence of the various geometrical parameters of the anchor body.The loaddisplacement curves of the local model and the bearing surfaces are analyzed and summarized.In addition,the relationships among the geometrical parameters,failure modes,and load capacity are discussed.(5)The relationship between the bearing capacity of multiple anchors structure and single anchor structure is studied.Considering the change of horizontal parameters,a bearing capacity formula of anchorage system is established.The causes of local failure,the failure mode of the whole structure,and the methods to improve the local mechanical behavior of the anchorage system are discussed.