Static Mechanical Performance And Parameter Analysis Of Concrete Arch Bridge With Multiple Arch Ribs

With the rapid development of Chinese transportation industry,higher and newer requirements have been imposed on bridge construction.Some bridges not only serve as engineering entities for transportation,but also must be matched with local environmental characteristics to make them a beautiful landscape.People love the special-shaped arch bridge for its strong sense of space and unique shape.However,the shaped arch bridge has complicated shape.Especially,there are many flexible adjustable members in the structure.Its stress and deformation are complex.There are few related theoretical studies.And the mutual reference is poor.For these reasons,the influence of design parameters on the static mechanical properties of structures is difficult to master.Therefore,it is necessary to carry out in-depth research and analysis on the static mechanical performance and design parameter sensitivity of the special-shaped arch bridge.This paper is based on Yuanlingxi Road multi-arch rib concrete-filled steel tube arch bridge.A finite element model is established to study the static mechanical properties of multi-arch rib concrete-filled steel tube arch bridge.Analyzing the influence of the wall thickness of the main and auxiliary arch rib steel tubes,the concrete filled in the arch rib steel tubes,the cable force(medium boom,side boom and horizontal cable),second-stage dead load,overall temperature and other design parameters on structural deformation and stress.The main research contents are as follows:(1)Using Midas Civil to establish an analysis model of multi-arch rib concrete-filled steel tube arch bridges,to conduct spatial static mechanical performance analysis and analyze the force characteristics and force transmission path of the bridge structure under load.In addition,calculating the deformation and stress of the structure under various load conditions.The results show that the vertical displacement of arch ribs exhibits an "M" shape deformation,transverse deformation only occurred on the side arch,and the maximum lateral camber deformation of the side arch vault was 11.16 mm.(2)Adjusting the structural design parameters to analyze the influence of each parameter on the structural deformation and stress.Then figuring out the influence low of the wall thickness of the main and auxiliary arch rib steel pipes,the concrete filled in the arch rib steel pipes,the cable force(medium boom,side boom and horizontal cables),second-stage dead load,overall temperature and other design parameters on the static mechanical properties of a multi-arch ribbed concrete-filled steel tube arch bridge.The analysis results show that the effect of the parameter changes on the structure is mainly reflected in the deformation and stress of arch ribs and steel main beam,the tension of the side hanger is the main parameter that affects the stress of the key section,and the overall temperature is the main parameter that affects the deformation of the key section.The parameters of the concrete filled with arch rib steel tube have little effect on the structural deformation and stress,which is secondary.parameter.(3)Using Design Expert test design software and considering the cross-effects of single factor parameters to perform multi-parameter regression analysis.Then exploring the sensitivity of the bridge's static mechanical properties to multi-parameter interactions,and obtaining the regression formula for structural response.By modifying the parameter level and substituting into the regression formula,the structural response value can be directly obtained.In the end,optimizing the structure globally.Comparing and verifying the static mechanical performance of the original structure.The results show that the optimization effect is better.