Construction technology for simply supported and continuously supported external prestressed continuous beam bridge T-shaped section

Abstract

The invention discloses construction technology for a simply supported and continuously supported external prestressed continuous beam bridge T-shaped section, which comprises the following steps of: a, prefabricating a concrete T-beam, and tensioning an internal prestressing tendon; 2, setting up the concrete T-beam, namely setting up the concrete T-beam hole by hole, and inserting an external prestressing tendon; c, pouring the concrete T-beam, namely pouring wet joints of the beam end on the top of piers to longitudinally form a continuous structure, transversely connecting cast-in-place wet joint transversely passing between wing plates and transverse clapboards into a whole, and tensioning the external prestressing tendon for the first time; and d, constructing a bridge floor system, and tensioning the external prestressing tendon again. The construction technology has the characteristics of convenient exchange of prestressing tendon, low friction loss, light hoisting weight of the beam body, easy assembly and construction, and thin thickness of bridge floor pavement.

Description

technical field [0001] The invention relates to a construction technology of a beam bridge, in particular to a construction technology of a T-shaped section of an externally prestressed continuous beam bridge which is simply supported first and then continuous. Background technique [0002] With the rapid development of high-grade highways in my country, the quality requirements of bridges connecting expressways have been increased accordingly, and bridge construction technology is extremely critical. The current status is that for high-grade highway bridges with small spans, prefabricated reinforced concrete slab girders are mostly used, and bridges with medium spans are in the form of prestressed concrete T (box) girders. For stressed concrete continuous girder bridges, the current construction method mainly adopts balanced cantilever pouring method or assembly method. However, because the construction of cast-in-place continuous beams is complicated, labor-intensive and ...

AI Technical Summary

Problems solved by technology

[0003] There are two problems in the investigation and analysis of existing highway bridges: on the one hand, quite a few bridges have been in service for 20 to 30 years, and the beams have suffered from concrete damage, spalling, corrosion of steel bars, cracks, etc., and the bearing capacity of bridges has been affected. On the other hand, due to the increase in traffic volume and the increase of vehicle load, the bearing capacity of some bridges is obviously insufficient and urgently needs to be reinforced, which has attracted the attention of the world

Since the 1960s, the protection problems of stay cables have been continuously solved and improved, and the anti-corrosion problem of external prestressing in the same category as stay cables has been well solved; A large number of steel bars are often arranged, and there are many bends. The crowded bends make the quality of grouting unable to be guaranteed, resulting in corrosion of the steel beams and affecting the durability of the structure. In the past 20 years, the general opinion in the world has tended to favor external prestressed steel. The structural durability of the harness is better than that of the internal harness

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