Construction method for simultaneous extension of parallel guide pits into double-line tunnel for TBM tunneling construction

Abstract

The invention relates to a construction method for simultaneous extension of parallel guide pits into a double-line tunnel for TBM tunneling construction and aims to guarantee simultaneous construction of the double-line tunnel and an I-line tunnel, put into operation at the same time and realize effective shortening of the total construction period of the tunnel and great reduction of the construction cost. The method comprises steps that small-diameter open TBM is utilized for full-section excavation in-advance construction of the parallel guide pits; after lagging behind the tunneling surface of the parallel guide pits about 800m, large-diameter TBM full-section tunneling construction of the I I-line is utilized at the left or right side of the parallel guide pits at 30-50m, and a transverse passage between the parallel guide pits and the I-line tunnel is constructed along the extension direction of the line at intervals; after lagging behind the TBM tunneling surface of the I-linetunnel about 1200 meters, extension construction of the parallel guide pits is carried out, that is, when the parallel guide pits are continuously tunneled without interruption by the small TBM ahead,the borehole-blasting method is utilized to carry out simultaneous digging extension of the constructed parallel guide pits at about 2km lagging behind the tunneling surface of the parallel guide pits, and the double-line tunnel is formed.

Description

technical field [0001] The invention relates to tunnel engineering, in particular to a construction method for synchronous expansion of parallel pilot pits in open-type TBM excavation construction into a double-track tunnel. Background technique [0002] With the rapid development of tunnel construction technology in my country and the continuous improvement of tunnel construction mechanization, the TBM (Tunnel Boring Machine) method, as an advanced construction method for tunnels, is increasingly used in my country's extra-long railway tunnels. In the construction of long or extra-long tunnels with good geological conditions, the use of open TBM excavation construction has the advantages of environmental friendliness, speed, quality, safety, and economy. Especially for extra-long tunnels, the construction period of the entire line is generally controlled, and TBM excavation is conducive to speeding up tunnel construction. progress, to realize the opening and operation of th...

AI Technical Summary

Problems solved by technology

[0004] The existing construction methods have the following deficiencies: (1) The parallel pilot pits set at the double track position are constructed by the traditional drilling and blasting method, and the construction progress is slower than the advanced TBM method of mechanical excavation, resulting in a longer period of time for the parallel pilot pits to penetrate (2) Since the two-line tunnels are relatively close to each other and interconnected cross passages are set up every 400m or so, the double-track tunnel will be expanded after the I-line tunnel is put into operation. Or the timing of the expansion and excavation operation is restricted by the driving of the I-line tunnel and needs to be adjusted to the skylight time; (3) Because the double-track project can only be expanded after the I-line tunnel project is completed, the total construction period of the whole tunnel increases, and the construction cost is high. It cannot be put into operation in time, which is not conducive to creating economic benefits; (4) The double-hole super-long tunnel is a mutual rescue and evacuation tunnel during the operation period, and the double-track tunnel is expanded and constructed during the opening and operation of the I-line tunnel. The function is limited, which is not conducive to the safety risk control during the operation of the I-line tunnel

Images