Method for carrying out rapid face excavation construction of loess tunnel by double rows of small conduits

Abstract

The invention discloses a method for carrying out rapid face excavation construction on a loess tunnel by double rows of small conduits, which comprises the following steps of: excavation and supporting of a side front slope, i.e. after completing earth excavation of the side front slope, immediately carrying out temporary protection of suspended net shotcrete on the side front slope; construction of a protection arch, i.e. excavating a tunnel face of an upper step tunnel opening, carrying out measure lofting, arranging the section steel frame protection arch from the arch top to the outside of the tunnel in a range of above a springing line and spraying concrete to the protection arch to form protection arch concrete; construction of advance supporting of the double rows of small conduits, i.e. drawing small conduit hole sites which need to be arranged on the tunnel face, then arranging the double rows of small conduits at the small conduit hole sites in the range of an arch part of the opening, carrying out grouting on the arch part by a grouting machine through the small conduits, and blocking off orifices of the small conduits after finishing grouting; and excavation and supporting of a tunnel body, i.e. after the protection arch concrete achieves the design strength and the construction of the double rows of small conduits in a first circle of the tunnel opening is completed, starting the loess excavation and supporting operation of the tunnel body. The method disclosed by the invention has a simple construction process and is easy to operate. The overexcavation phenomenon is effectively reduced. The construction cost is reduced.

Description

Technical field [0001] The present invention involves the field of tunnel construction technology, and specifically involves a dual -row small catheter in the loess tunnel. It is suitable for the construction of tunnel construction in a slightly dense and above wet and above wet loess geology. Background technique [0002] During the construction of the loess tunnel, large deformation or even collapsed accident occurred. In the past, the design institute generally adopted a large tube shed support for the construction of the loess tunnel.The overallness is better. The disadvantage is that the construction cycle is long. First, the construction of the arches should be constructed. Demonstration of the dedicated equipment. The outer interapchers is not easy to control. The excavation block causes a large super excavation, and the cost is higher.Therefore, it is urgent to use a simple, easy -to -operate, economic tunnel construction excavation method. Invention content [0003] The...

AI Technical Summary

Problems solved by technology

[0002] During the construction of loess tunnels, large deformation and even landslide accidents are prone to occur. In the past, design institutes generally used large pipe shed support for loess tunnel entry construction. The advantages of large pipe shed advance support are safe and reliable, and the length of one-time advance support is long. , the integrity is good, the disadvantage is that the construction period is long, the arch guide wall needs to be constructed first, and the holes are drilled with special equipment.

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