Construction method of shallow-buried long-span tunnel under the existing high-speed railway

Abstract

The invention discloses a construction method in the railway field, in particular relates to a construction method of a large-span tunnel passing through a rapid transit railway with a shallow tunneling process. The construction method comprises the following construction steps of: 1, advance supporting and pre-reinforcing; 2, partial excavation and millisecond blasting; and 3, short-bench excavation support construction. In a construction process, grouting technologies such as curtain grouting, full-section grouting, radial grouting and the like are used for blocking an underground water seepage channel to control the loss of underground water; and in the construction process, an automatic high-precision monitoring method and a fixed target high-precision monitoring method are adopted for carrying out monitoring to ensure that the influence of tunnel passing-through construction on rapid transit railway tracks on the ground surface is immediately found. By using the construction method, the safety of the tracks can be ensured when a newly-built railway passes through ballastless tracks.

Description

technical field [0001] The invention discloses a construction method in the field of railways, and in particular relates to a construction method for a shallow-buried long-span tunnel when a newly-built line crosses an existing track-free track line. Background technique [0002] At present, my country's high-speed railway construction is developing rapidly, and the line has strict requirements on foundation settlement. During the construction of the new line, it will inevitably need to cross the existing ballastless track line. The settlement control requirements of the ballastless line are strict, and the settlement after construction is not allowed to exceed 15mm , the existing underground excavation tunnel construction technology is shallow buried in the tunnel, during the construction period, groundwater loss, settlement is inevitable, it is difficult to control the surface settlement within the allowable range, so it is necessary to study the tunnel excavation and suppor...

AI Technical Summary

Problems solved by technology

[0002] At present, my country's high-speed railway construction is developing rapidly, and the line has strict requirements on foundation settlement. During the construction of the new line, it will inevitably need to cross the existing ballastless track line. The settlement control requirements of the ballastless line are strict, and the settlement after construction is not allowed to exceed 15mm , the existing underground excavation tunnel construction technology is shallow buried in the tunnel, during the construction period, groundwater loss, settlement is inevitable, it is difficult to control the surface settlement within the allowable range, so it is necessary to study the tunnel excavation and support construction technology by steps, various advanced Reinforcement, water-stop grouting construction technology, automatic monitoring and measurement technology to ensure the safety of existing line construction