Analysis Of The Influence Of Undercrossing Bridge On The Stability Of Existing Yangtze River Bridge And Its Countermeasures

With the rapid development of our country's national economy and transportation,the existing traffic such as roads,bridges and tunnels can no longer meet the increasing demand for transportation.This provides a new platform for the development of high pier interchange bridges,Pier bridge as a solution to the growing demand for transport of a new direction.Nowadays,more and more engineering practice shows that new bridges have been getting closer and closer to each other and have even crossed the existing bridges due to such factors as topography and geology.In the process of construction,the new bridge will inevitably affect the deformation and force of the bridge pier.If we do not conduct systematic and scientific research and propose relevant measures,it may destroy the existing bridge structure And will endanger pedestrians,traffic safety,causing unnecessary economic losses.This article relies on the bridge project of Zhongxian Yangtze River Bridge under Hongxing Viaduct along Hongxing district of Zhongxian County in Chongqing City.The construction of high pier foundation of Hongxing Viaduct has caused the settlement and stress of both the pillar of Zhongxian Yangtze River Bridge The Yangtze River Bridge Bridge overall stability and other issues were studied.When the Red Star Viaduct gradually construction to 10 #,Pier 11 at the moment when wearing Zhongxian Yangtze River Bridge 11 # and 12 # piers,the lower part of the piers designed as column pier.When in the vicinity of the intersection of the two bridges in the bridge under construction on the existing bridge is complex,construction difficult.The finite element ANSYS software was used to carry on the numerical simulation.The effect and influence scope of the pier under the pier construction on the existing bridge were analyzed.The comparison between the simulation data and the real-time monitoring measurement data shows that the measured value is better than the finite element simulation.After simplifying the model and geological conditions,through the study under the bridge pier 10 #,11 # pier under construction gradually through the existing Yangtze River Bridge,the paper found:1.Under the pier pier construction excavation will have an impact on the surrounding rock,and proposed two based on the approach construction program.The first scheme is to dig through the Hongxing viaduct pier with a depth of 24 meters and excavate eight holes of pile # 1,#(2),(3)# and # 11 and(2),(3),(4)# of pile # 10 at the same time.The second scheme is to simultaneously excavate four holes of(1)and(3)piers of Pier # 10 and pier(1)and(3)of Pier # 11 of Hongxing viaduct pier with an excavation footage of 4 meters and complete the pier(2)and(4)of Pier 10 and 11 # pier(2),(4)pier four holes at the same time excavation,excavation footage is also 4 meters.2.During the construction of pile # 10 and # 11 of Hongxing Viaduct in Scheme 1 and Scheme 2,the impact on the overall stability of 11 # and 12 # piers and bridges of the Yangtze River Bridge after the completion of the bridge is small,and the influence of displacement and stress are within the allowable changes Therefore,based on the existing geological survey and design,both excavation schemes of Hongxing viaduct pile foundation are feasible from the static analysis point of view.3.Through the comparison of two construction schemes,it is found that the settlement and horizontal displacement of No.11 and No12 pier of Zhongxian Yangtze River Bridge all meet the requirements.After construction and completion of bridge,The settlement and horizontal displacement of piers are all less than that of scheme one.If scheme two is used,the influence on the displacement of pier # 11 and the soil stress between pier and pier of Zhongxian Yangtze River Bridge during the whole construction and bridge construction are all less than that of scheme one.Therefore,from the perspective of static and construction safety,it is suggested that the excavation scheme of Hongxing Viaduct be used for excavation of this project.4.The finite element software ANSYS is used to analyze the settlement of the adjacent existing bridge foundation due to the construction of the new bridge foundation,and the maximum settlement limit is proposed to analyze the overall stability of the existing bridge.Through the summary analysis of the stress and displacement of the existing bridge piers,it is concluded that the new bridge high pier will not affect the overall stability of the existing bridge during construction.