Combined framework steel structure of jacked subway bridge and method for jacking subway bridge

Abstract

The invention discloses a combined framework steel structure of a jacked subway bridge. The combined framework steel structure comprises a square main frame structure and sub frame structures, wherein the main frame structure consists of vertical oblong frameworks, a longitudinal upper supporting beam at the top, a transverse top cross beam, a spacing beam, a longitudinal lower supporting beam at the bottom and a transverse bottom cross beam, which are fixedly connected into a whole through bolts; and the sub frame structures are positioned at the upper part of the front end of the main frame structure. The method for tunneling a subway bridge comprises the following steps: jacking the sub frame structures at intervals to reduce resistance during jacking and disturbance to the soil, and jacking the square main frame structure; digging soil under the support and shield of the sub frame structures and the main frame structure, and delivering out the soil of a dug surface; and repeatedly and circularly jacking till the reinforced concrete subway bridge is jacked to a designed position, and detaching the combined framework steel structure at the front end. The combined framework steel structure can be assembled for jacking the subway bridges or culverts of different sections, and can greatly save steels and construction cost by repeated use; and the method can ensure soil holding pressure balance, stable excavating surface and safe operation, reduce speed limit of lines and reduce the influence on transportation.

Description

technical field [0001] The invention relates to a device and a method for excavating a railway or road subgrade road bridge, in particular to a combined frame steel structure for jacking a tunnel bridge and a method for jacking the tunnel bridge. Background technique [0002] With the frequent speed up of domestic railways, a large number of level crossings need to be rebuilt into the form of overpasses, and more of them use the way of underpassing overpasses. In order to keep the traffic running, the jacking method is often used for construction; the prefabricated rectangular concrete tunnel will be The bridge or culvert pipe is jacked into and passes through the subgrade of the existing railway or road, so as to facilitate the crossing of cars, pedestrians, pipelines and cable interchanges. During construction, when the prefabricated rectangular concrete tunnel bridge is jacked into the soil layer of the subgrade, the soil needs to be continuously dug out to continue jacki...

AI Technical Summary

Problems solved by technology

During construction, when the prefabricated rectangular concrete tunnel bridge is jacked into the soil layer of the subgrade, the soil needs to be continuously dug out to continue jacking; in order to maintain the operation of the upper railway or road, the traditional construction method is to use I-beams , Convenience beams and other reinforcement measures or speed-limited operation, this laborious and time-consuming reinforcement method can no longer meet the requirements of high-speed railway and expressway operations that are constantly increasing in speed

In the later period, shield tunneling technology used for excavating tunnel bridges has been more and more widely used due to its safety and high efficiency. However, the existing shield tunnels are welded together, and a shield tunnel of one specification can only be used to adapt to its design section. The tunnel bridge construction has no versatility; excavating tunnel bridges with different sections requires the design and processing of new shields, which increases the construction cost

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