Excavation tunnel construction method

Abstract

The invention discloses an excavation tunnel construction method. An excavation tunnel is constructed through a CD method and has the total length of 37.7 m, and each guide hole is constructed througha step method and excavated annularly with core soil reserved and has the step length not smaller than 5 m; the excavation tunnel is excavated from the left guide hole and the right guide hole, eachguide hole is provided with an upper step and a lower step, the core soil is reserved in the excavating process, depressurizing grooves are formed, manual excavation is adopted, and the excavation stability is ensured; three grids are continuously erected at an ingate at the interval of 400 mm, the distance between the last grid and the upper grid is 550 mm, and the other distances are 500 mm. Seventy-six grids are used in total. Steel welding pipes with the diameter of 40*2.75 adopted for small guide pipes have the length of 2 m and the annular distance of 300 mm and are longitudinally spacedfrom the grids; upper step construction, lower step construction, advanced grouting, soil body excavation, grid erection, primary support construction, feet-lock bolt arrangement, concrete spraying and behind-primary-support grouting are sequentially completed, the construction efficiency is high, and the construction effect is good.

Description

technical field [0001] The invention relates to the technical field of tunnel construction, in particular to an excavated tunnel construction method. Background technique [0002] After the 1990s, many cities in our country began to launch subway projects, and began to introduce and apply international advanced shield construction technology and equipment on a large scale. The subway projects were rapidly constructed in some cities, and the ground subsidence technology covered by them developed accordingly. my country's application of the shield method to build tunnels began in Shanghai in the 1950s and 1960s. With the in-depth research of shield tunneling method and the increase of engineering applications, the construction technology of shield tunneling method has been developed and improved. In recent years, shield tunneling technology has made significant progress. There are also differences in the mastery of the construction techniques and technologies of different me...

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Problems solved by technology

With the in-depth research of shield tunneling method and the increase of engineering applications, the construction technology of shield tunneling method has been developed and improved. In recent years, shield tunneling technology has made significant progress. There are also differences in the mastery of the construction techniques and technologies of different methods. Although the national and some local standards can control the surface settlement within +10~-30mm, tunnels can be excavated safely at a distance of less than 1m from existing buildings and structures. The deformation of buildings and structures can be controlled below 2-5mm and other surrounding environmental protection issues have been uniformly stipulated, but some problems are still prone to occur in the application, which is always one of the construction problems

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