Self-balancing external prestressing strengthening method for bridge structure

Abstract

The invention relates to a self-balancing external prestressing strengthening method for a bridge structure. The self-balancing external prestressing strengthening method is characterized by comprising the following steps of: carrying out interface processing at a connecting place (5) of a top flange of a concrete beam; (2) inserting reinforced bars at the connecting place (5) of the top flange of the concrete beam; (3) installing the reinforced bars at the connecting place (5) of the top flange of the concrete beam; (4) installing the reinforced bar of a steering block (6) and a diverter (9) at the bottom of the beam; (5) symmetrically adding diaphragm plates at a place far away from the end of the beam by 2-3m, and installing an anchorage device (10); (6) concreting the connecting place (5) of the top flange of the beam, the steering block (6) and the newly added diaphragm plates (8); and (7) installing and tensioning an anchoring external cable, thus obtaining a self-balancing external prestressing strengthening structure. An external prestressing system can be used for detecting and adjusting the stress of the cable at any time, inspecting the corrosion condition of the cable and can also be used for maintaining and replacing the cable when necessary. The self-compacting concrete solves the problems of dense reinforcement assembly, complex structure, narrow space of formworks and traditional structural members, cavities caused by the blocking of aggregates and the like, effectively ensures the dense degree of placing concrete and increases the strengthening effect. The self-balancing external prestressing strengthening method can be used for strengthening heavy railroad brides, concrete box girders and T beams.

Description

technical field [0001] The invention relates to the field of bridge and structural engineering in civil engineering, in particular to a method for reinforcing and strengthening a bridge superstructure and a construction process, in particular to the rapid strengthening and upgrading of heavy-duty railway bridges. Background technique [0002] With the continuous deepening of large-scale construction of high-speed and passenger-dedicated railways, my country's railway high-speed and rapid passenger transport network has gradually formed. model. Therefore, the heavy-duty reconstruction and evaluation of existing railway bridges is one of the urgent problems to be solved in my country's railways. [0003] Heavy-duty railways have large transportation capacity and significant economic and social benefits. The development of heavy-duty railway transportation has become the development direction of railway transportation in all countries in the world, and it is also the main way f...

AI Technical Summary

Problems solved by technology

Affected by structural form or material properties, these traditional reinforcement methods have certain limitations

[0007] (1) When adopting the reinforcement method of enlarged section, if the design fails to analyze from the point of view of the overall structure, it is only enlarged for local enlargement, which will cause other parts of the overall structure to form weak layers and cause major damage; The mass and stiffness of the component section will change, and the natural frequency of the structure will also change, and it is very likely to enter the frequency of earthquake or wind shock to generate resonance phenomenon

[0008] (2) Although the construction process of the bonded steel reinforcement method is relatively simple, it can improve the bearing capacity of the structure to a certain extent, but it has higher requirements on the smoothness and cleanliness of the surface of the beam body, and the effectiveness of the reinforcement mainly depends on the bonding material. Strength and durability, fatigue resistance is not stable enough

[0009] (3) The improvement of structural rigidity by FRP reinforcement is not obvious, the problems of shear resistance and connection are relatively prominent, and the durability and fire resistance of the bonded surface between FRP material and concrete are poor

[0010] To sum up, traditional reinforcement methods have defects such as insufficient connection reliability of old and new materials, limited improved bearing capacity, and poor durability.

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