Construction method of intersection point of civil air defense tunnel with broken surrounding rock

Abstract

The invention discloses a construction method of an intersection point of a civil air defense tunnel with broken surrounding rock. The construction method comprises the following steps that double-rowadvanced small pipes are placed before construction, and then a tunnel is excavated and built according to a three-benching tunneling method; a positioning bar is placed, steel arches are placed in an area according to the positioning bar positioning, connecting bars are adopted to connect between steel frames to form a primary support system; then a system anchor bolt and a feet-lock bolt are drilled; when the construction of an intersection section of a newly constructed tunnel and an excavated tunnel are carried out, two sides of arch foot of an upper bench of the primary support of the newly tunnel cross-section are placed on the vault support surface of the excavated tunnel; reinforcing sections are arranged at the intersection position of the two sides of the arch foot to enhance the stability; and the primary support of the excavated tunnel below the newly constructed tunnel is dismantled to carry out a second lining construction. The construction method of the intersection point of the civil air defense tunnel with broken surrounding rock is widely suitable for a large cross section crossing tunnel with shallow coverage, rock body fragmentation and strict settlement control, can effectively control the settlement deformation of the fragmentation rock body, and the construction safety and the overall stability of the intersection of new and old tunnels are ensured.

Description

technical field [0001] The invention relates to a construction method for breaking the intersection of surrounding rock civil air defense tunnels. technical background [0002] In recent years, with the rapid take-off of my country's economy, the transportation industry, which is closely related to people's lives, has also ushered in the spring of development. In terms of underground space utilization, not only roads and railway tunnels are built to meet travel, but also underground shopping malls and civil air defense tunnels. In the process of building civil air defense tunnels, in order to meet the conditions of saving land, reducing the construction period, and protecting ancient buildings, etc., it is possible to pass through the already built tunnels during construction. In the process of passing through the existing tunnels, the newly built tunnels may have an impact on the structure and surrounding rock of the existing tunnels, and in severe cases may lead to the in...

AI Technical Summary

Problems solved by technology

In the process of passing through the existing tunnels, the newly built tunnels may have an impact on the structure and surrounding rock of the existing tunnels, and in severe cases may lead to the instability and destruction of the existing tunnels

Especially when passing through the existing tunnel under the condition of broken rock mass, the shape of the section is relatively complex, and stress concentration is particularly easy to occur in some areas of the corner, which may cause problems such as surface collapse during the construction process

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