Study On Stability Of Tunnel Anchor Model Test For Mountain Railway Suspension Bridge

Suspension bridges are well known for their powerful ability to cross the topographic features,having significant advantages in cost saving,environmental impact and so ono In our country,especially in the vast western mountain area,more and more suspension bridges appear.Compared with the general highway suspension bridge,the railway suspension bridge is more powerful,heavy load and in line with China's national conditions.so it has higher requirements for the bearing capacity and stability of the rock mass.Therefore,the study on the bearing capacity and stability of the railway suspension bridge becomes more and more important.The Jinsha River bridge in the construction is China's first railway suspension bridge,both sides of the bridge adopt the tunnel anchorage and hold field model test on both sides.Field model test data are used to test its reliability under design load and stability in multiple overload conditions,and to find out the law of displacement change,load transfer law and failure mode.The similarity ratio of the field model test is 1:10,and the similarity ratio is the biggest in the past years,which reduces the influence caused by the size effect and ensures the accuracy of the data.This paper based on the engineering test is carried out to study the system of the model anchorage and surrounding rock,through the finite element software ABAQUS,the elastic model of concrete anchorage is adopted and the Mohr Kulun model is applied to the surrounding rock establish the finite element model of the system of the anchorage and surrounding rock,analyzes displacement of structure and stress distribution in rock excavation,concrete pouring and applied load to determine the stability of the structure system,gets failure mode of structural system in overload conditions to determine the safety coefficient.In the whole excavation for field model test provide strengthening suggestions' of structural system,and the calculated results can be used as the supplement of the future experimental data of field model test and be compared to verify with it.