A main girder bottom plate structure of a wide box girder bridge and its construction method

Abstract

The invention discloses a wide box girder bridge main beam bottom board structure. The wide box girder bridge main beam bottom board structure is characterized in that bottom longitudinal beams which are arranged at intervals along the transverse direction of a bridge and bottom board thickened cross beams which are arranged at intervals along the longitudinal direction of the bridge are arranged at the upper parts of bottom boards on which bottom board pre-stressed reinforcement sections are arranged; the bottom boards which are positioned under bottom board pre-stressed reinforcing bars are provided with unbonded pre-stressed reinforcing bars which correspond to the bottom board thickened cross beams and are transversely arranged; two ends of the unbonded pre-stressed reinforcing bars are upwards bent in positions which are close to main beam webs, and are anchored on the top surfaces of the bottom board thickened cross beams after penetrating through the bottom board thickened cross beams. Through the wide box girder bridge main beam bottom board structure disclosed by the invention, the stiffness of the bottom boards can be enhanced; the radial forces of the bottom board pre-stressed reinforcing bars on the bottom boards can be basically offset by the unbonded pre-stressed reinforcing bars, and the unbonded pre-stressed reinforcing bars and the bottom board pre-stressed reinforcing bars are combined, so that the bottom boards can be effectively prevented from cracking and deforming due to the action of the radial force.

Description

technical field [0001] The invention relates to highway bridges, in particular to a main girder bottom plate structure of a wide-width box girder bridge and a construction method thereof. Background technique [0002] The wide-width box girder bridge in the present invention refers to that the average thickness of the bottom plate (the average value of the sum of the thickness of the bottom plate at the mid-span of the main girder and the thickness at the root of the main girder) is 1 / 50 to 1 / 20 of the width of the bottom plate Single-box single-chamber prestressed concrete continuous girder bridge and prestressed concrete continuous rigid frame bridge. [0003] The main girder of this wide box girder bridge is prone to cracking during construction and after the bridge is put into operation due to the following reasons: [0004] The height of the main girder at the mid-span and side fulcrums is small, and the height at the middle fulcrum is relatively large. The beam height...

AI Technical Summary

Problems solved by technology

The problems of this method are that the design of the anti-collapse reinforcement lacks basis, including whether the anti-collapse reinforcement is set, the spacing of the setting, the grade and diameter of the anti-collapse reinforcement used, etc. are not directly regulated; The corrugated pipe that completely buckles the prestressed steel bars of the bottom plate is not easy to play a role; the third is that it cannot solve the problem of insufficient rigidity of the bottom plate itself

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