Inspection And Strengthening Of Simply-Supported Slab Bridges

The maintenance, inspection and strengthening of bridge structures is one of the most important tasks after put into use, and it is also the basis for the structures to function to their potentials and ensures the safety of traffic. Due to the present situation of road traffic, the importance and urgency of bridge maintenance and strengthening is emerging.In this paper, experiments and theoretical calculations are implemented so as to study the inspection of concrete, inspection of bridge structures and external prestressing strengthening in concrete bridges. The specific contents are as follows:1. Discussion of the principles and methods for the inspection of concrete structures in terms of the strength of structural concrete and the states of steel bars. To link up with practical inspection, the significance, essentials and contents of bridge inspection are discussed. Common problems and their countermeasures in the inspection of bridges are brought out.2. By means of load experiment and destructive experiment, the mechanic properties of prestressed concrete hollow slab bridge are studied. Calculations by usual method and FEM method are carried out respectively to estimate the ultimate bearing capacity of the slab, and a comparison and analysis between the calculation outcomes are made.3. External prestress strengthening method is adopted to reinforce the slab both transversely and vertically, and the specific method and procedures are discussed, and the effect of reinforcement is calculated. On a self-made concrete beam, FEM software ANSYS is adopted to analyze its whole process of destroy, and thus to check the reliance of ANSYS on this matter. An attempt to strengthen concrete beams by the method of external prestress is made, and the effect of reinforcement as well as the mechanic properties are discussed.Experiments and calculations illustrate: concrete simply supported slabs reinforced by the method of external prestress are remarkably improved in terms of their bending capacity, and their ultimate capacity is increased dramatically with obvious strengthening effect. In the absence of practical experiment, it is reasonable to carry out a simulation using the FEM software ANSYS, whose results are reliable to a certain extent.