Deformation control method for dismantling continuous box girder bridge midspan closure segment

Abstract

The invention discloses a deformation control method for dismantling continuous box girder bridge midspan closure segment. The deformation of a closure segment is controlled through a restraint device, a stiff steel rib is arranged on the upper surface of a closure segment top plate in the bridge direction, and a hollow jack is arranged on the upper part of a cushioning end of the stiff steel rib.Two ends of a boom are fastened with nuts, and a hydraulic pressure control system is connected with the hollow jack to constitute a whole restraint device. After the closure segment is cut, the lowering of the displacement of the hollow jack is controlled by the hydraulic pressure control system, embedded squeeze force between the restraint device and the closure segment is released, and the nuts, nut shims, the hollow jack, the boom and the stiff steel ribare removed successively to achieve the deformation control of the closure segment. The deformation control method for dismantling continuous box girder bridge midspan closure segment is simple in structure, flexible in design, safe and reliable, economical in use, light in weight, large in working area, convenient for multi-span synchronous construction, convenient for assembling and dismantling, and does not need large machineryand provides a simple and effective method for removing the deformation control of the closure segment.

Description

technical field [0001] The invention relates to a deformation control method in the process of demolishing a bridge, in particular to a deformation control method for dismantling a mid-span closing section of a continuous box girder bridge, belonging to the field of bridge engineering. Background technique [0002] As of the end of 2017, the number of highway bridges across the country has exceeded 800,000. At present, more than 100,000 bridges in my country's highway network are dangerous bridges. Some of the dangerous bridges are prestressed concrete continuous box girder bridges. There are two main treatment methods for such dangerous bridges: one is reinforcement and reconstruction, and the other is demolition and reconstruction. [0003] The common construction methods of prestressed concrete continuous box girder bridges include full support method, cantilever method (including cantilever assembly method and cantilever pouring method), simply supported first and then c...

AI Technical Summary

Problems solved by technology

The counterweight method is to arrange a certain weight of load in the adjacent span of the cut span, so that the side span is deformed downward and the cut span is deformed upward, so as to reduce the final vertical deformation and corner deformation of the cut span. The bearing capacity of the adjacent side spans of the original structure puts forward higher requirements. Generally, the bearing capacity of old dangerous bridges decreases, which is difficult to meet. Therefore, the use of this method is strictly limited.

The lower temporary support method is to cut the lower part of the span and carry out local or full support. This will occupy the lower clearance of the bridge for a long time. It cannot be used for the case where the bridge is a waterway, and it cannot fully reflect the flip demolition method. The advantages

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