Experimental Study And Finite Element Analysis Of Hollow Slab Bridge Strengthened By Prestressed CFRP

The strengthening technology of prestressed CFRP bridge is a new strengthening technology developed in recent years.Carbon fiber board is widely used in bridge reinforcement at this stage because of its advantages in material properties,convenience and practicability.Strengthening technology of Prestressed CFRP bridge is an active strengthening method.The characteristics of light weight and high strength combined with the technology of bonding carbon fiber.It can greatly improve the bearing capacity of the old bridge and improve the old bridge crack,deflection and other diseases.This method has a superior development trend in the reinforcement of old bridges.This dissertation focuses on a 13 m hollow slab bridge in Hebei Province.In view of the present situation that there are many diseases in 13 m hollow slab bridge,the reinforcement test is carried out.The method of static load test and numerical theory research is adopted.Through the comparative analysis of domestic and foreign literature,we chosen the strengthening method of Prestressed CFRP.However,due to the strict conditions of the tensioning device and the anchoring device,there are few applications in the actual bridge,in view of the shortcomings of previous studies,the main contents of the dissertation are as follows:(1)At present,there is need to be improved for the design method of CFRP reinforcement technology.In this dissertation,the key points in the strengthening technology of CFRP slab bridge are studied in detail.Through the investigation of domestic and foreign literature and reference to relevant specifications are deduced the value range of prestress,the value of tension control stress and the calculation of prestress loss.And the selection of anchorage system is analyzed.(2)In current research,due to the limitation of the reality.Most of the experiments are based on the ideal scaled beam model in the laboratory.This is not consistent with the fact that most of the bridges in the actual project have been used and some diseases exist.In this dissertation,an old reinforced concrete hollow slab bridge which has been in service for 17 years in Hebei Province is selected for reinforcement test.The dynamic and static load tests of the damaged bridge under different working conditions are carried out.The applicability of this technology isverified by comparing the experimental data before and after the reinforcement.(3)Based on dynamic and static load test conditions,theoretical study on method of finite element numerical simulation of test bridge.Comparison of its calculation results,erify the feasibility of this reinforcement method.The two methods work together to verify the reliability of the strengthening technology of prestressed CFRP.The results show that the prestressed CFRP reinforcement technology can effectively inhibit the deflection and stress growth of hollow slab girder bridge.At last,it plays a strong theoretical support for the popularization and application of this technology in practical engineering.