Simulation of composite strengthening technique in prestressed concrete continuous box beam bridges

The damage features of concrete continuous box beam bridges are summarized combined with three prestressed concrete continuous box beam bridges on ZhengLuo highway. There are four common strengthening methods in bridge engineering practice, i.e. bonded steel plates, strengthening with R.C, carbon fiber reinforced polymer (CFRP) and external prestressed strands. By numerical analysis technique of three dimension finite element (3D FE), the stresses of the damaged bridge are compared with the results of the strengthened one which is strengthened by one of the former methods. The strengthening effectiveness of those methods is ascertained. Therefore, the composite strengthening technique (CST) is established, which is effective to improve the bearing capacity and crack resistance of the strengthened bridge. An optimal strengthening process is put forward in the paper. So the CST is reasonable and effective to strengthen a damaged prestressed concrete continuous box beam bridge, which provides a significant reference for other similar strengthening projects.