Method for determining construction sizes of tunnel and cavern

Abstract

The invention discloses a method for determining the construction sizes of a tunnel and a cavern. The method comprises the following steps of: determining the rock mass natural horizontal stress sigmahav and vertical stress sigmah of a position where a tunnel is positioned, and determining a natural stress ratio coefficient; determining rock mass natural horizontal stress sigmahav and vertical stress sigmah of a position where a tunnel is positioned, and determining a natural stress ratio coefficient mu=sigmahav / sigmah; checking a tunnel construction size envelope line curve chart to obtain the range of a construction size ratio eta; initially determining the vertical semi-axis size n of a construction tunnel; and calculating the horizontal semi-axis size m of the construction tunnel. According to a tunnel / cavern construction size obtained by using the method, a surrounding rock structure can adapt to natural stress gravity distribution variation caused by underground cavern excavation to the maximum extent, the surrounding rock structure is stressed reasonably in a redistributing process, and the self-carrying capability of surrounding rock is positively brought into play. The method is simple, economic and practical; the surrounding rock structure stress characteristic principle basis is embodied, the requirements on the quality of design and construction personnel are lowered greatly, and excavation support costs on the tunnels and caverns can be greatly lowered.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, in particular to a method for determining the construction size of a tunnel chamber. Background technique [0002] With the development of highway tunnel and railway tunnel construction in our country, the concept of new Austrian tunnel construction has been increasingly accepted by tunnel design and construction technicians. Its essence is to make reasonable use of the self-bearing capacity of the surrounding rock, use monitoring and measurement, and carry out timely support to save costs. As we all know, the core technology of tunnel and underground cavern construction can be attributed to the two key processes of excavation and support, that is, how to excavate can be more conducive to the stability of the cavern; how to support can more effectively ensure the stability of the cavern and facilitate the next step of excavation. However, although the existing tunnel construction is...

AI Technical Summary

Problems solved by technology

However, although the existing tunnel construction is implementing the essence of the new Austrian method in thought, it is not carried out according to the characteristics of the actual surrounding rock in actual operation. 1. The support structure is too conservative. From the perspective of safety, sometimes the bearing capacity of the surrounding rock is completely ignored. Although the concept of the new Austrian method is followed on the surface, it actually deviates from the concept of the new Austrian method, resulting in a waste of manpower and financial resources.

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