Parameter analysis of steel box girder incremental launching construction with auxiliary tower

• 1、School of Civil Engineering, Chongqing Jiaotong University, Chongqing 400074, China
• 2、Chongqing Juneng Construction (Group) Co., Ltd., Chongqing 401120, China
• 3、Chongqing Juneng Construction Group Road and Bridge Engineering Co., Ltd., Chongqing 401329, China

Abstract：To study the stress behavior of large-span steel box girder, guide beam, and temporary tower in temporary tower assisted incremental launching construction, a finite element analysis model was established based on the Fenshui River Bridge with a 90 meters main span. Sensitivity analysis was conducted on parameters such as structural self weight, temporary tower height and stiffness, temporary cables position, cables force and stiffness under maximum cantilever state. The results indicate that cable position is a sensitive parameter for the downward deflection of the front end of the guide beam. When the horizontal projection lengths of the outer and inner cables increase by 20%, the downward deflection of the front end of the guide beam decreases by 73% and 38%, respectively. Outer cables should be set in an area with a horizontal projection length of 0.6~0.8 times the maximum cantilever length. Additionally, the cables force is a sensitive to temporary tower deviation. It is found that when the outer and inner cables forces increase by 33% and 50%, the temporary tower deviation decreases by 169% and 136%, respectively. The self weight of the guide beam is a sensitive to the stress of the steel box girder. When the self weight of the guide beam increases by 20%, the tensile and compressive stresses of the steel box girder increases by 43% and 37%, respectively. The results of this article can provide reference for the construction of similar bridges.)

Keywords： steel box girder incremental launching construction temporary tower temporary cable stress deformation parameter analysis