Using The Residual Stiffness And Accumulation Of Damage In-service Highway Bridges

In this paper we have carried on idiot investigations and structural damage detections on WangBridge of Province Way 101 in YuCheng . And in this special bridge, half is two-way curried arch bridge and half is reinforced concrete bridge. Based on the different damage conditions of the two structures, the bridge destruction mechanism is analyzed theoretically. The history and present condition of the fatigue properties study of the reinforced concrete flexural member are reviewed in this paper. Firstly, the relation of M and the curvature parameter κ. are described and the effect of deterioration laws of oblique section stiffness by repeated loads are given .Secondly, the relationship between displacement and load, stresses distribution, cracks distribution ,load stages ,limited load of the R.C beams are studied by static tests .Thirdly ,the fatigue properties of the R.C beams are studied by fatigue tested .Dynamic modules and damage variable denoting the fatigue properties of the R.C beams are proposed .The damage variable is defined as the deterioration of the cyclic modules .And the deterioration laws of the stiffness of the R.C beans by the fatigue cumulate damage are thoroughly studied in this paper .Fourthly ,based on the test results and theoretical analysis ,a mathematical mode describing the decrease of the dynamic modulus with cycle number is given .The model can be used topredict the fatigue life of the R.C beams .Fifthly , according to the calculation result of WangQiao detection data, the presenting way of predicting the fatigue life of R.C beams is tested. Finally, according to actual engineering some suggestions about durability of concrete and stretching the life of bridges are given.