Underground cave depot excavation support stability discrimination method based on energy mutation

Abstract

The invention belongs to the technical field of underground cave depot stability analysis. The invention mainly provides an underground cave depot excavation support stability discrimination method based on sudden energy change. The method is based on a mutation theory and a cusp mutation model. Through the work of the system when the flat arch is changeddeformation, and a work and energy increment balance relationship of a system when in displacementdisplaced, the relationship can be incrementally balanced; establishing a system potential function expressed by a flat arch variable deformationstate is established; the stable state of the system is judged by using a sharp pointthe cusp mutation model; the physical significance of instability of the surrounding rock of the cave depot can beillustrated; a cavern arch surrounding rock arch axis curve is used as a state variable; the established cave depot excavation support stability criterion is clear in physical significance and easy and convenient to use, the reliability of cave depot excavation support stability judgment is greatly improved, an advanced means is provided for underground low-side-wall large-span cave depot excavation support stability judgment, and a powerful basis is provided for cave depot excavation support stability prediction and early warning.

Description

technical field [0001] The invention belongs to the technical field of stability analysis of underground caverns, and mainly proposes a method for judging the stability of excavation support of underground caverns based on energy mutation. Background technique [0002] At present, the stability analysis methods of underground caverns commonly used at home and abroad include: engineering geological analogy method, block balance theory method, elastic or elastoplastic analysis method, numerical simulation method, physical model test method and nonlinear analysis method, etc. In relevant specifications, such as: GB 50487-2008, SL 279-2002, the stability criterion of the surrounding rock of the cavern is mostly based on the deformation value or deformation rate, such as the ultimate strain criterion of the surrounding rock, the inward convergence displacement of the surrounding rock and the convergence It is believed that when the deformation amount or deformation rate of the su...

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Problems solved by technology

[0002]At present, the stability analysis methods of underground caverns commonly used at home and abroad include: engineering geological analogy method, block balance theory method, elastic or elastoplastic analysis method, numerical simulation method, physical model test method and nonlinear analysis method, etc. In relevant domestic and foreign codes, such as: GB 50487-2008, SL 279-2002, the stability criterion of the surrounding rock of the cavern is mainly based on the deformation value or deformation rate, such as Surrounding rock ultimate strain criterion, surrounding rock inward convergence displacement and convergence ratio criterion, etc., it is considered that when the deformation amount or deformation rate of surrounding rock exceeds a certain value, the rock mass will be destroyed. The existing cavern stability judgment method is generally applicable to medium and small span caverns, and the criteria and models in the existing codes have a large range, low accuracy, and a single method, and it is difficult to meet the requirements for the stability of the excavation and support of large-span caverns with a short side wall span greater than 40 meters. For the short side wall span For long-span caverns larger than 40 meters, due to the lack of engineering analogy data, physical model tests, numerical simulations, theoretical analysis and other comprehensive evaluation methods, the stability judgment has not yet formed a standard

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