Force Transfer Mechanism Of Tunnel Anchorage In Large Span Suspension Bridge And Optimal Control Of Contributing Factors

Anchorage is a significant component of large span suspension bridge.As one of the major forms ofmain cableanchoring,the tunnel anchorageis superior in its low construction costs and good environmental effect.Nevertheless,the utilization of tunnel anchorage is largely restricted due to its complex force transfer mechanism and immature theoretical calculation method,as well as the scarcity of measured data.Since the bearing capacity oftunnel anchorage is effected by its length,buried depth,axis angle,extend angle,shape of cross section,size of cross section and geological conditions ofsurroundingrock in some degree,it is necessary to make comparison and analysis of these factors,andoptimal control of them need to be conducted.Meanwhile,due to the scarcity ofproject case,relatively little study on force transfer mechanism and failure mechanism of tunnel anchorage is carried out,which is essential in the optimization design and safety assessment of anchorage system in suspension bridge.Therefore,further discussionneed to be conducted on the base of analysis and summarization of former study.In this thesis,the force transfer mechanism and failure mechanism of tunnel anchorageis summarized at first.Meanwhile,methods of recognizing the stability of slope with tunnel anchorageis discussed(the 2nd chapter).Then,the paper summarized the contributing factors that influence the bearing capacity of tunnel anchorage.Utilizing FLAC3D5.0,the finite differencemethod(FDM)software,influence of factor levels on bearing capacity of tunnel anchorage is conductedqualitatively by numerical simulation analysis,involvingburied depth,shape of cross section and size of cross section(the 3rd chapter).Besides,on the base of tunnel anchorage engineering project of Puli extra-large bridge in Yunnan,orthogonal test is designed to take optimal control of contributing factors,and the influence degree of these factors is compared.Meanwhile,the paper has analyzed the standardsdistinguishing the failure of tunnel anchor,and presented the failure mechanism of it by applying overload to the system.(the 4th chapter).At last,based on the above engineering project,numerical simulation of the construction process is performed and presented on the paper,and relevant issues are also discussed(the 5th chapter).