Fast large-cross-section tunnel construction method adapting to complicated and variable geological conditions

Abstract

The invention discloses a fast large-cross-section tunnel construction method adapting to complicated and variable geological conditions. Middle walls and steps are combined, whether the arrangement of temporary inverted arches of each steps and middle partition walls of upper, middle and lower steps is needed or not is determined according to actual geological condition change conditions and field monitoring information in the tunnel construction process, when the rock surrounding condition becomes poor in the tunnel construction process, temporary support and protection of each excavated parts are respectively implemented, when the rock surrounding condition becomes good, a plurality of small excavated parts can be combined into a large excavated part until the full cross-section one-step excavation forming method is adopted, and division positions of each excavated parts in the construction process is not changed. The method has the advantages that in the construction, the conversion problem of the construction method does not exist when the geological conditions are changed, the construction speed of large-cross-section tunnels under the complicated and variable geological conditions is greatly accelerated, the construction work period is shortened, and the construction cost can be properly reduced.

Description

technical field [0001] The invention relates to a construction method of a tunnel, in particular to a rapid construction method of a large-section tunnel adapted to complex and changeable geological conditions. Background technique [0002] Since the tunnel is located in the underground rock and soil layer, the stratum conditions it traverses cannot be single, including uneven softness and hardness on the cross section, and continuous changes in stratum conditions along the longitudinal section of the tunnel, especially for large-section tunnels. , the inhomogeneity of the strata it traverses will be more significant. At present, for the construction of large-section tunnels, according to the different geological conditions that the tunnel passes through and the supporting conditions of construction machinery and equipment, the full-section method, step method and partial construction methods (including CD, CRD and double-side wall method) are mainly used at home and abroad....

AI Technical Summary

Problems solved by technology

The conversion between the full-section method and the step method is convenient and the construction speed is fast, but the construction safety cannot be guaranteed when encountering weak and broken ground

However, partial construction methods such as CD, CRD, and double-side-wall pilot pit method reduce the large cross-section into small sections, shorten the single excavation span, and are conducive to the stability of tunnel construction. However, these partial construction methods have many construction procedures. The interference between each process is large, the construction speed is slow, and the multiple blasting excavations cause frequent disturbances to the surrounding rock, and there are many temporary supports to be removed, which cannot achieve the purpose of economical and rapid construction; especially when encountering When the geological conditions of the tunnel change, there are problems such as difficulty in switching between construction methods, long construction period, high cost, and poor construction quality.

[0003] Generally speaking, under complex and changeable geological conditions, tunnel construction methods need to be changed frequently, and the existing various sub-construction methods are very troublesome to switch between each other, which seriously affects the construction progress and cannot meet the requirements of rapid tunnel construction.

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