Research on the Jacking Construction Monitoring Technology of High-Pier,Long-Span and Long-Continuous-Unit Steel Box Girder
Taking the Linyi Huanghe River Bridge in Yuncheng,Shanxi as the engineering background,the key technologies and control methods of high-pier,long-span and long-continuous-unit steel box girder bridges in the process of jacking construction are introduced.The bridge adopts a multi-point synchronous jacking scheme,the total jacking distance of the bridge is 3 816 m,the length of the single jacking is 1 912 m,the maximum cantilever length of the jacking is 128 m,and the maximum pier height is 99 m,belonging to high position jacking.The jacking length,jacking cantilever length,and jacking height are all the world's first.Because the jack is arranged at the center line of the pier top 2.5 m,and the steel girder is affected by the temperature load,the bridge pier bears the large eccentric pressure and horizontal thrust in the construction process;the guide beam is deflected down up to 1.6 m when the maximum cantilever is reached,the difficulty of climbing the pier is relatively high;affected by many factors in the construction process,the linear control of the steel box girder is difficult.In order to ensure the safety of construction,finite element software is used to refine the analysis of the construction process,the construction scheme is optimized based on the analysis results,and the key monitoring of the bridge structure status under key working conditions is carried out,and the error is analyzed and controlled in combination with the monitoring data.Through the effective monitoring of the jacking process,the stress safety of concrete piers,guide beams,steel box girders and other components is ensured,and the linear shape of the main beam is smooth after the beam falls,which meets the requirements of the design target.
high pierlarge-spanlong-continuous-unitjacking constructionmonitoring and controlling
万方数据
维普
