A Deformation Control Method for Soft Rock Tunnels Based on Bolt Force Analysis

Abstract

The invention discloses a soft rock tunnel deformation control method based on anchor rod force analysis. A soft rock tunnel is excavated and subjected to deformation control construction from back to front according to multiple segments, and when any segment is excavated and subjected to deformation control construction, the method includes the steps that 1, surrounding rock basic mechanical parameters are determined; 2, the tunnel reserved excavated volume is determined; 3, the tunnel is excavated; 4, a tunnel preliminary bracing structure is determined; 5, tunnel deformation control construction is carried out, wherein in the tunnel preliminary bracing construction process, a flexible mold bracing structure is constructed from back to front; 6, a next segment is excavated and subjected to deformation control construction; 7, the step 6 is repeated multiple times till the full excavation and deformation control construction process of the soft rock tunnel is completed. The soft rock tunnel deformation control method is reasonable in design, convenient to achieve and good in use effect, the reserved excavated volume is determined according to the surrounding rock deformation condition of the soft rock tunnel, the flexible mold bracing structure is adopted for carrying out full-section bracing on the tunnel, the flexible mold bracing structure and the tunnel preliminary bracing structure are in coordination deformation, and deformation of the soft rock tunnel can be effectively controlled.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a method for controlling deformation of soft rock tunnels based on force analysis of bolts. Background technique [0002] In recent years, with the rapid development of my country's highway and railway construction, the construction of soft rock tunnels under the conditions of large buried depth and high ground stress has become one of the inevitable trends in the development of the transportation field. Wushaoling Tunnel, Zhongnanshan Tunnel and Xiakou Tunnel, etc. Due to the harsh engineering geological conditions, the self-supporting capacity of the surrounding rock is poor, and the deformation of the soft rock tunnel is severe. If the support is not timely or the plan is unreasonable, large deformation of the surrounding rock and damage to the lining structure will easily occur. For this reason, a large number of experts, scholars and on-site engineeri...

AI Technical Summary

Problems solved by technology

In fact, for large-deformation soft rock tunnels under specific geological conditions, even the 120mm upper limit reserved deformation allowed by the code cannot meet the requirements of continuous deformation of soft rock after initial support, and the strain energy of surrounding rock cannot be fully released. Eventually lead to the failure of the steel arch and the instability of the surrounding rock

So far, there is still a lack of comprehensive theoretical research on the reserved deformation system for excavation of large-deformation soft rock tunnels.

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