| At present,most suspension bridges have been built with gravity anchorage,while tunnel anchorage can greatly reduce the amount of concrete.With the implementation of the "Western Development Strategy" in China,the number of long-span suspension bridges is gradually increasing,and with the increase of bridge span,the stress of cable increases,and the impact on anchorage and surrounding environment is intensified.Therefore,this paper mainly through on-site investigation and data collection,literature research,numerical simulation and other means,based on the engineering background of Luding Dadu River Bridge,establish the numerical model of tunnel anchorage which is used to study the safety and stability of adjacent tunnels,adjacent slope and anchorage structure itself.Research shows:(1)In the excavation and support of the anchor chamber,the overall deformation of the tunnel support structure presents a upward sliding trend;on both sides of the anchor chamber area,there are boundary differences in the deformation of the tunnel structure;The tunnel support structure is in compression state,local tension,and the whole structure is stable.Under the action of the main cable load,the maximum uplift deformation of the tunnel support structure increases,which is consistent with the actual phenomenon.(2)With the construction of anchor chamber,the uplift and settlement deformation of slope reach the maximum peak value of deformation.The range of slope disturbance is gradually enlarged,and the plastic zone is more widely distributed.The whole slope is in compression,there is no local tension state,and the whole slope is stable.Under the action of the main cable load,the uplift deformation is intensified,a large range of shear plastic zone appears,and the disturbance range is increased,which is consistent with the existing research.(3)Under the main cable load,compared with the filling of the anchor plug,the uplift deformation of the anchor increases by 34.03%,and the settlement deformation decreases by 38.81%.The deformation and stress of anchor chamber support increase abruptly during the excavation of anchor chamber,so it is necessary to pay attention to the reinforcement measures during the construction.The normal displacement of the interface is36.77 times larger and the tangential displacement is 37.71 times larger under the main cable load than when the anchor plug is filled.The laws explored can provide reference for similar projects. |
