Method for improving bearing capacity of truss girder bridge through external prestressed tendons

Abstract

The invention discloses a method for improving the bearing capacity of a truss girder bridge through external prestressed tendons. In the implementation process, a truss main beam, longitudinal prestressed tendons, oblique prestressed tendons, supports, side stand columns, supporting cross beams and anchoring devices need to be used. The side stand columns are arranged at vertical web members close to the two sides of truss pier supports and used for anchoring the oblique prestressed tendons and transmitting vertical loads of anchoring forces to the piers. The supporting cross beams are arranged along the span, one side of each of the oblique prestressed tendons is anchored to one supporting cross beam, and the other sides of the oblique prestressed tendons are anchored to the side stand columns; and opposite pulling and anchoring are conducted between each pair of supporting cross beams parallel to the lower chord of the truss main beam through longitudinal prestressed tendons, so that the truss main beam is reinforced and tensioned in the vertical plane. The bending moment of the midspan area of the truss girder can be effectively reduced, the load bending moment is relatively balanced and reasonable in the span direction, the girder height of the truss is reduced, the sectional dimension of a truss rod piece is uniformized, and industrial manufacturing and design and connection of gusset plates are facilitated.

Description

technical field [0001] The invention relates to a method for improving the bearing capacity of a truss girder bridge by using external prestressed tendons. Background technique [0002] The steel truss girder bridge uses the space structure composed of steel trusses as the cross-sectional form of the main girder. The truss girder bridge is composed of the main truss, connecting system, bridge deck system and bridge deck. The main truss is the main load-bearing structure of the steel truss girder bridge, which is composed of upper chord, lower chord and web, and its main function is to bear the vertical load and transfer the load to the support. The members of the main truss are connected by gusset plates to form nodes, and the force and structure of the nodes where diagonal members meet are particularly complicated. There are positive and negative bending moments in continuous girder bridges, and the internal force at the middle fulcrum changes greatly. Therefore, it is oft...

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Problems solved by technology

However, external prestressing technology is mostly used in concrete bridges, and is rarely used in the field of steel bridges.

The cables of the steel truss short-tower cable-stayed bridge are similar to the external prestressed tendons, but the short-tower cable-stayed bridge still needs a certain height of the main tower to provide the anchorage end, which increases the construction time and cost, and is not suitable for those with construction constraints. high bridge

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