Construction technology with alternative cutting removal and segmental re-jacking of double-side-wall temporary supports in shallow-buried silty-fine sand layer

Abstract

The invention relates to a construction technology with alterative cutting removal and segmental re-jacking of double-side-wall temporary supports in a shallow-buried silty-fine sand layer, and belongs to the technical field of rail traffic construction technologies. The construction technology includes the steps of carrying out zonal, regional, sectional and segmental construction on a double-side-wall pilot tunnel 6 and a double-side-wall pilot tunnel 9 with an alternative bay method, removing the temporary supports, chiseling away primary support concrete, and then cutting away grid arch trusses. The support removal length and part are adjusted and controlled with an alternative cutting and re-jacking method, rapid re-supporting is achieved, the temporary supports are partially removedand timely bear stress by re-jacking instead of being removed at the same time, and it is guaranteed that the temporary supports are in a stress state all the time in the construction process. According to the construction technology with alterative cutting removal and segmental re-jacking of the double-side-wall temporary supports in the shallow-buried silty-fine sand layer, the temporary supports are removed from inside to outside part by part in each segment of 6-8 m with the alternative bay method, the construction safety can be guaranteed, and multiple working faces can be constructed atthe same time to accelerate the construction progress.

Description

technical field [0001] The invention relates to the technical field of rail transit construction technology, in particular to a construction technology for jumping, cutting, dismantling, and segmented roofing of temporary supports on double side walls of shallow buried silt and fine sand layers. Background technique [0002] The crossing area of ​​the underground railway often forms a large-span tunnel with variable cross-section due to functional requirements. After summarizing the construction methods often used in the construction of the domestic subway crossing area, it is concluded that the shallow buried underground excavation method is currently the preferred method, but because of the large span, it is often used. Supplemented by the CRD method or the double-side-wall pilot tunnel method to control the surface settlement caused by excavation, especially in weak surrounding rock formations. If the temporary support is removed improperly, it will cause excessive deform...

AI Technical Summary

Problems solved by technology

If the temporary support is removed improperly, it will cause excessive deformation of the initial support or local internal force exceeding the bearing limit, resulting in safety accidents