Surrounding rock displacement early-warning method based on damage dilatancy theory

Abstract

The invention discloses a surrounding rock displacement early-warning method based on a damage dilatancy theory. The surrounding rock displacement early-warning method comprises the following steps that 1, a calculation formula of surrounding rock pressure pi is obtained based on a traditional Fennar formula through elastic mechanical solution, a dilatancy coefficient k is introduced, the dilatancy effect of the damage dilatancy and deformation of a surrounding rock along with the excavation process is considered, and a formula, giving consideration to the dilatancy effect of a surrounding rock damage zone, of cavity wall displacement u0 is obtained; 2, hierarchical displacement calculation considering the dilatancy effect is conducted on the surrounding rock in the damage dilatancy zone;3, according to stress-strain curve characteristics in the rock damage dilatancy process, a three-level early warning safety management design system is established, and construction safety control isguided. A surrounding rock three-level damage dilatancy early-warning state is established so that the cavity wall displacement situation can be more really and accurately predicted, and the influence of a supporting structure is considered, therefore, the method can be also carried out according to the characteristics of different design stages such as preliminary design and construction design,is very easy to popularize and has an engineering application value.

Description

technical field [0001] The invention relates to the technical field of underground engineering construction, in particular to a surrounding rock displacement early warning method based on the theory of damage expansion. Background technique [0002] The tunnel excavation process of mining method construction often adopts dynamic monitoring and measurement method for early warning control, among which displacement monitoring is one of the main methods. Generally, the change process of displacement is monitored, and the safety is judged according to the displacement rate and total displacement. Therefore, displacement early warning The value and its prediction become the key issue. For this problem, there are three main methods at present: theoretical calculation, normative empirical value determination and numerical calculation. Due to the complexity of the numerical calculation process, it has not been popularized in the design and construction process, and the normative ex...

AI Technical Summary

Problems solved by technology

At present, the theoretical and standard calculation methods used in the project have large errors between the prediction results and the actual results. The main reason is that the expansion effect of the surrounding rock excavation loosening process is not considered. The determination of the safety early warning control value is very empirical and lacks scientific basis.

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