The Research Of Arch Foot Crack And Control Strategy Of CFST Tied Arch Bridge

With the application of concrete filled steel tube in Bridge Engineering and the maturation of construction technology without scaffold,arch bridge ushered in a new development.In the bridge of inland waterway project,the number of under supported concrete filled steel tubular(CFST)arch bridge on the new bridge project in the proportion is increasing.But through on the survey of some CFST arch bridges found that the arch foot of these bridges generally have cracking phenomenon.Basis on the investigation of some CFST arch bridges,this paper sums up the characteristics of the arch foot crack,and analyzes the key construction of the CFST arch bridge.In order to find out the reason of arch foot crack,in this paper,first processing whole analyse of bridge strcture by applying Midas civil software,and then through Midas FEA software to establish the arch foot solid model for calculation and analysis.After calculating and analyzing,the reason that leads to the crack of arch foot is the construction of the steel tube arch rib concrete pumping.This construction process causes stress concentration in the arch foot and the tensile stress produced exceeds the tensile strength of concrete.In order to control the problem of cracking of the arch foot,this paper presents the encryption of arch foot stirrup spacing of ordinary steel bar,the optimization of steel tube thickness and some other measures.And these measures are also proved.Through the inspection results of some CFST arch bridges which take these measures,the result shows that the crack of the arch foot is effectively controlled.