Identification and evaluation of bed separation induced by mining based on beam-column and stress-balanced arch theory

Abstract

Identification and evaluation of bed separation induced by mining in the overburden is critical to prevent secondary disasters during coal mining. Traditional theoretical methods ignore the effect of horizontal stress in bed separation and fail to accurately identify bed separation and evaluate its dynamic evolution process. In this study, based on the beam-column theory, the deflection of composite beam is determined, in which the horizontal stress is considered. On this basis, by combining beam-column and stress-balanced arch theory (BS theory), the BS model is proposed for identification and evaluation. The identification results from the BS model agree well with the field measurement results with a high accuracy rate of 88.9%. Furthermore, one working face in a coal mine is selected to evaluate the dynamic evolution process of bed separation by the numerical simulation and the BS model. It is found that the bed separation shows evident stages of growth and extinction during mining. The BS model has a wide range of applications for the identification and evaluation of bed separation induced by mining and can be used to ensure the safety of mining operations.