Instability mechanism and energy evolution of surrounding rock at intersections of deep multi-form application

• Published in: Journal of Central South University Vol. 31; no. 3; pp. 890 - 911
• Main Authors: Wu, Yi-yi, He, Man-chao, Li, Hui, Gao, Yu-bing, Xie, Sheng-rong
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.03.2024; Springer Nature B.V
• Subjects: Cross-sections; Damage; Disasters; Distortion; Engineering; Failure analysis; Failure mechanisms; Mathematical analysis; Mathematical models; Metallic Materials; Reinforcement; Repair; 应用形式; application forms; 精细化模型; distortion energy density; 畸变能密度; refined model; 围岩失稳; roadway intersection; surrounding rock instability; 巷道交岔点
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-024-5567-x

As mining progresses into deep strata, severe damage occurs at various long-life roadway intersections. To guide targeted repair and reinforcement operations, it is necessary to investigate the failure mechanism of surrounding rock at intersections in deep environments. Four categories and 16 types of intersections of connection type, interleaving type, bifurcation type, and rotary type (ring triangular column) are comprehensively summarized by investigating the maintenance of intersections in many mines. Three types of typical application forms of intersection points are proposed: a single large-scale intersection point, two intersection points for nested combined application, and an intersection point group for ring triangular rock column application. The failure of intersections on site is divided into three levels: local damage to the surrounding rock, damage to the triangular rock column, and overall damage. Three categories of 13 disaster-causing factors of external environmental factors, their structural attributes, and artificial design hidden hazards are proposed from the initiation and cause of the disaster, and the disaster-causing paths of various disaster-causing factors are described in detail. The refined intersection models under three application forms are established, and the secondary development of numerical software is carried out to introduce the distortion energy density index to analyze the energy of the surrounding rock. Studies have shown that the surrounding rock distortion energy peak at intersections is in the triangular rock column, and the increase coefficient is about 2.5. Meanwhile, the distortion energy of the surrounding rock also accumulates at the maximum section, and its increase coefficient is about 1.5. Therefore, it is proposed that the repair of the intersection should focus on the reinforcement of the triangular rock column and surrounding rock at the large cross-section, and a targeted plan is proposed for the repair of the intersections of the deep mine, focusing mainly on the reinforcement of the triangular rock column and the large cross-section. This study provides a reference for the analysis of failure factors, the introduction of numerical simulation indicators, and the repair support of deep intersections.