Negative Bending Moment of T-beam Reinforced

The bridge used in the project is designed as a left and right split bridge deck. The upper structure adopts the prestressed concrete continuous T beam with the left width of 16*40m and the right width of 11*40m. The lower structure adopts column pier, thin-walled pier and pile foundation, and the bridge abutment adopts column platform, bench platform and pile foundation. The total length of the bridge is 547m. The width of the bridge deck is 0.50m (crash barrier) + 12.00m (travel lane) + 0.50m (crash barrier) = 13m, and a single width is 5 pieces of T beams. The defect is located at the position of the 1# side beam on the top of the 2# pier on the right side, and the 2# pier is a consolidation pier. . During the implementation of the bridge deck system, it was found that some of the T-beam pre-buried scuppers were not standardized, and the operation team simply adopted drilling scuppers for rectification. When reaching the 2# pier on the right side, vertical drilling was carried out at the horizontal drain hole by mistake, and it was found that the steel strand was drilled and broken. After the accident investigation, it was found that the side beam of the second hole was drilled and broken by the N2 steel bundle at the 2# pier, and the 3 steel strands in the N3 steel bundle were drilled and broken.

Considering that the bridge has completed the concrete pavement of the bridge deck and entered the final stage of construction of the subgrade contract section, it needs to face objective problems such as tight construction period and interface handover. , and cause unnecessary waste. After design and demonstration, it is feasible to choose the treatment method of structural strengthening. After comprehensive comparison, in the case of other construction difficulties in restoring broken beam steel strands, the prestressed carbon plate scheme is finally selected for treatment.

The prestress generated by the prestressed carbon plate can effectively offset the effects of the bridge structure's dead weight and operating vehicle load, improve the structural rigidity and reduce the structural deflection. It can give full play to the characteristics of controllable construction period, low construction complexity, high construction safety, and good construction precision, and reduce the cost of processing projects as much as possible, avoiding unnecessary waste.

This scheme design uses 100*3mm2 prestressed carbon plate for reinforcement

The prestressed carbon fiber plate has excellent shaping properties. In addition to the traditional field surface pasting method, this application is used between the structural layers, making full use of the optional flat size of the prestressed carbon fiber plate and the high degree of combination of the bridge deck structural design features. It achieves the ideal treatment effect of high precision, easy operation, relatively low cost and short construction period.

The prestressed carbon fiber plate has a significant effect in improving the flexural bearing capacity of the beam and increasing the safety reserve of the overall bearing capacity of the bridge. In a specific engineering environment, there is still a lot of room for developing and applying its material properties.