Retractable prestressed arch structure and construction method

Abstract

The invention provides a retractable prestressed arch structure. The structure comprises an arch arranged in a chamber and prestressed sliding components. The prestressed sliding components comprise drivepipes, sliding rods and high strength springs, and further comprise a primary sprayed concrete layer, an arch back interval sprayed concrete layer, and a permanent sprayed concrete layer. The primary sprayed concrete layer is arranged on the inner side of the arch back interval sprayed concrete layer. The invention further provides a corresponding construction method of the retractable prestressed arch structure. Prestress load is formed in a prestressing spring mode to change a traditional passive stressed state of the arch. The drivepipe structure is adopted to improve the working stateof thee sliding parts. The stable mechanical property of the high strength springs is combined to form stable sliding load, and the defect of unstable sliding load of a traditional retractable arch isovercome.

Description

technical field [0001] The invention relates to the technical field of tunnel construction engineering, in particular to a shrinkable prestressed steel arch frame and a construction method, which are suitable for initial and permanent support of large deformation tunnels. Background technique [0002] With the development of various infrastructure constructions in our country, deep-buried long tunnel projects that pass through high-stress areas and have harsh engineering geological environments continue to emerge. The problem of large deformation of tunnels under high-ground stress and soft rock conditions has become increasingly prominent, and endangers engineering safety. The construction concept of the new Austrian method is to release the initial stress of the rock mass and exert the self-stabilization ability of the rock mass as the core idea, which has positive significance for promoting the progress of the construction technology of soft rock large deformation tunnels....

AI Technical Summary

Problems solved by technology

Practice shows that this kind of sliding part has the disadvantages of unreliable sliding force and low strength of arch support, which also greatly restricts the application of this kind of support structure in permanent engineering

Moreover, at present, the arch support structures in tunnel excavation and support are all passive force-bearing structures, and do not have the function of applying prestress.

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