Prejudgment method for bulging instability of any stratum of layered bottom plate of equally spaced bottom anchor roadway

Abstract

The invention discloses a prejudgment method for bulging instability of any stratum of a layered bottom plate of an equally spaced bottom anchor roadway. On the basis of assumptions of basic conditions, a mechanical model of the layered bottom plate of the equally spaced bottom anchor roadway is established; through mechanical analysis, a maximum normal stress equation and a maximum shear stress equation of a combined rock beam structure are obtained when the number of anchor rods is singular and even and the anchor rods are arranged at equal intervals; according to structure destruction formand conditions, a mechanical judgment equation of the layered bottom plate of the equally spaced bottom anchor roadway is established, numerical values of basic parameters of the model are obtained from field data and substituted into the mechanical judgment equation, and a prejudgment result about whether or not the stratum of the layered bottom plate of the equally spaced bottom anchor roadway has stability is obtained. Prejudgment of the structural stability is accurate and comprehensive, a reliable theoretical basis is provided for a flexing and folding bottom bulging treatment technology,and a great theoretical meaning and a practical engineering application value are provided for ensuring safe exploitation of deep resources in China and improving the safety of mining workers.

Description

technical field [0001] The invention relates to the fields of mine support technology and rock mechanics, and in particular to a method for predicting the instability of roadway layered bottom plate swollen at equal intervals. Background technique [0002] Coal is the main part of my country's primary energy consumption. The demand for coal and the production scale of coal mines are increasing moderately year by year. With the increase of production scale, large-section roadways appear, the mining depth gradually develops deeper, and the strength of surrounding rocks decreases relatively. The current situation has led to problems such as large deformation, large ground pressure, and difficult support in the roadway, which seriously threaten the safety of coal mine production. Floor heaving is a dynamic phenomenon that often occurs in coal mine roadways. Due to the changes in the stress state and properties of the surrounding rock in the roadway due to excavation, mining and m...

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Problems solved by technology

[0004] In recent years, many experts and scholars at home and abroad have done a lot of research and experimental work on the control of flexural and wrinkled floor drums, and proposed many floor drum prevention technologies. In the soft case, only focus on the reinforcement of the bottom plate and ignore the fracture mechanism of the layered bottom plate, resulting in delamination and fracture of the layered bottom plate, the overall strength is greatly reduced, and the layered bottom plate will form secondary horizontal stress on the two sides. According to the literature search, there are few studies on this part, and there is a lack of prediction method for the stability of the layered floor of the roadway with equal spacing bottom anchors.

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