Method for judging tunnel plate cracking buckling type rockburst

Abstract

The invention discloses a tunnel plate cracking buckling type rock burst judgment method which comprises the following steps: establishing a circular tunnel plate cracking buckling type rock burst thin plate mechanical model by considering the interaction between rock plates; establishing a rock plate flexural deflection equation; calculating the total potential energy generated by bending deformation of the four-side simply-supported rock plate according to the thin plate theory and the stress condition of the rock plate; calculating the maximum bending deflection of the rock plate under theaction of an external load by adopting a minimum potential energy principle; when the rock plate is damaged, the ultimate bending deflection of the rock plate after bending is calculated; and comparing the maximum bending deflection with the limit bending deflection to judge whether rock burst occurs or not. Aiming at the defects that an existing mechanical model ignores the interaction between split rock plates and the like, a circular tunnel thin plate mechanical model considering the horizontal stress between the rock plates is established, the bending deflection of the rock plates under the load action is calculated by adopting the minimum potential energy principle, and is compared with the ultimate deflection of tensile failure, so that the rock burst judgment method is obtained.

Description

technical field [0001] The embodiments of the invention belong to the technical field of underground engineering, and in particular relate to a method for judging rockbursts of slab-crack buckling type in tunnels. Background technique [0002] With the development of economic construction and the consumption of shallow resources, underground engineering construction and resource development are gradually moving to deep, showing the development trend of "long length, large number, large cross-section, and deep burial". Deeply buried underground projects often have a higher level of in-situ stress due to the increase in burial depth. For example, the diversion tunnel of the Jinping II Hydropower Station has a maximum burial depth of 2525m, and the maximum in-situ stress is expected to reach 72MPa; The in-situ stress can reach 56.6MPa, and increases linearly with the increase of buried depth; the maximum buried depth of Xikang Qinling Railway Tunnel is about 1600m, and the maxi...

AI Technical Summary

Problems solved by technology

However, in actual engineering, the width and height of rock slabs formed by splitting of surrounding rocks are equal, and are much larger than the thickness of the slabs, so it is not appropriate to regard it as a plane strain problem

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