A Directional Support and Reinforcement Method for Layered Surrounding Rock Tunnels in High Ground Stress Environment

Abstract

The invention discloses a directional support and reinforcement method of a stratiform surrounding rock tunnel in a high ground stress environment. The method comprises the steps that necessary rock mechanics parameters are acquired, a numerical calculation model is established, and experiment parameters are substituted into the numerical calculation model for calculation; a discrete unit numerical model of the occurrence of the surrounding rock stratum and the axial direction of the tunnel under the actual intersection angle is established, and the deformation characteristics of surrounding rock after excavation are calculated; according to numerical values of a displacement field of the tunnel section, radial displacement isolines of the tunnel section after excavation are determined; according to the distribution characteristics of the isolines, key parts of directional support in practical engineering are determined; the range, depth and support range of the directional support ofthe key parts are determined; and according to the failure characteristics of simulation results, an anchorage method is selected pointedly. The directional support and reinforcement method of the stratiform surrounding rock tunnel in the high ground stress environment have the advantages that uneven extrusion deformation of lamellar surrounding rocks caused by interlaminar cracking and shear slipcan be effectively prevented, the design change in the construction process is reduced, the construction progress is quickened, the engineering investment is effectively saved, and the directional support and reinforcement method is suitable for the design and construction of all types of stratiform tunnel surrounding rocks.

Description

technical field [0001] The invention relates to the fields of engineering geology and geotechnical engineering, in particular to a method for directional support and reinforcement of layered surrounding rock tunnels in high ground stress environments. Background technique [0002] Layered surrounding rock is common in tunnel engineering. The deformation and failure of surrounding rock during excavation is mostly affected by the strength of the structural plane of the rock mass. The spatial relationship between the occurrence and the excavation direction of the section is controlled by the anisotropy of deformation, namely Local excessive deformation will occur around the section, [0003] The existing design codes mainly adopt the bolt-spraying support technology of the new Austrian method for the initial support design of the surrounding rock of the traffic tunnel, that is, the anchor bolts of the system should be uniformly arranged radially along the tunnel periphery, and ...

AI Technical Summary

Problems solved by technology

Passive and isotropic reinforcement methods not only cannot effectively prevent interlayer cracking and non-uniform extrusion deformation of the flaky surrounding rock, causing engineering accidents, but also cause unnecessary damage to the reinforcement range and reinforcement force due to excessive parameter values. consume

As a result, a large number of design changes occurred during the tunnel construction process, unnecessary waste of project investment was generated, and the construction progress was seriously affected.

Images