Applicability of Yielding–Resisting Sand Column and Three-Dimensional Coordination Support in Stopes

Abstract

In view of the existing problems of stope roadways, which are difficult to maintain under the influence of high ground and mining-induced stresses, the structural characteristics and movement regularities of stopes surrounding rocks were analysed. Through the construction of a three-dimensional mechanical model of the coordination support of a stope, the adaptability index of the support in stope is presented, and its mechanism of operation is expounded. Yielding–resisting sand column (YRSC) sidewall-support technology with satisfactory compressibility and supporting strength was developed. The structure and actual mechanical properties of the YRSC were investigated through laboratory experiments, and the optimum ratio of filling materials was obtained. The good applicability of the load and deformation adaptability index of the three-dimensional coordination support in the stope and YRSC sidewall-support technology were demonstrated in practice at the No. 12306 working face of the Dongda coal mine. It was shown that the designed carrying capacity and compression of the sand columns satisfied the site requirements. The actual stress and deformation of the YRSC exhibited three stages: Slow growth at the initial stage, a large increase in the medium term, and a stable trend at the end. The adaptability index of the three-dimensional coordination support in the stope considers all bearing structure units of the stope as an interconnected whole, and the stability conditions of the stope roadway can be quantitatively described. The supporting effect of the YRSC is remarkable and can be applied to the construction of tunnels, bridge systems and other engineering fields.

Study on the Fracture Law of Inclined Hard Roof and Surrounding Rock Control of Mining Roadway in Longwall Mining Face

“…Shen et al [13] used stress sensors, microseismic (MS) monitoring systems and other methods to study the stress evolution law and rock formation failure characteristics in the stress concentration area during face mining, and found that the MS positioning signal active area and stress dissimilation area mostly appeared in the vicinity of faults, joints and other geological structures that provide a basis for regional monitoring and early warning of working faces. Meng et al [14] analyzed the structural characteristics and movement laws of the surrounding rock of the working face and believed that in the deep mining process, the working face roadway is affected by the superposition of high ground stress and mining disturbance stress, and it is difficult to maintain its own stability. Yield-resistant sand column (YRSC) sidewall support technology ensures the stability of the surrounding rock structure of the working face roadway.…”