Failure Analysis of a Pre-Excavation Double Equipment Withdrawal Channel and Its Control Techniques

Abstract

The use of pre-excavation equipment withdrawal channels (EWCs) at the stop-production line is important for the rapid withdrawal of coal mining equipment. However, during the final mining period, the dynamic pressure of a pre-excavated double EWC is severe, which leads to instability of the surrounding rock around the EWCs. Therefore, in this paper, the methods of field monitoring, theoretical analysis, and numerical simulation were used to systematically study the stress and plastic zone evolution of a double EWC during the final mining period. Firstly, the distribution characteristics of mining abutment pressure and roadway failure modes under the action of mining abutment pressure were analyzed theoretically. Afterward, a FLAC3D mining numerical model was established according to the distribution of rock strata obtained from roof detection. Finally, the evolution laws of the stress fields and plastic zones of the EWCs during final mining were obtained by numerical simulation. The present study suggests that asymmetric stress distribution dominates asymmetric failure of the surrounding rock around the EWCs during the final mining period, and deformation failure within 10 m from the working face to the main EWC (MEWC) accounted for most of the roadway deformation. Based on the research results combined with actual production experience, the stability control technique of the surrounding rock with reinforcement of anchor cables and double-row buttress hydraulic support for the MEWC was put forward. After the field application, the ideal result was obtained.

Comprehensive Study on Surrounding Rock Failure Characteristics of Longwall Roadway and Control Techniques

“…Furthermore, scholars have used different experimental and numerical methods to collate a large number of field application cases [16][17][18][19][20]; this is also expected to serve as a reference for future research in this field. Researchers have reported that the principal stress has a significant influence on the stability of roadway surrounding rocks [21][22][23][24]. Therefore, when studying the stability of roadway surrounding rocks, it is necessary to analyze the influence of the principal stress on the distribution of the plastic zone.…”

Roof Failure Mechanism and Control Technology of Large Section Open‐Off Cut in Soft Rock Strata with Thin Thickness

“…Li et al [13,14] obtained the failure modes of deep roadway through field monitoring and proposed specific control schemes through numerical analysis, which provided references for engineering governance under similar geological conditions. e research results of large section roadway engineering are described [15][16][17]. Based on the practical problems in underground mining of coal mine, Hu et al [3,18] studied the supporting technology of large-span open-off cut.…”

Deformation and Failure Mechanism of Surrounding Rock in Mining‐Influenced Roadway and the Control Technology

“…e stability control technology of the surrounding rock with a long bolt is studied and applied in the face of the butterfly failure roadway. Considering the stress environment of surrounding rock of the deep mining roadway, Ma et al [13,14] proposed the mechanical mechanism of the formation of the plastic zone in surrounding rock under nonisobaric conditions and its morphological and discussed the influencing factors of roof stability. Yuan et al [15,16] clarified the mechanical conditions for the formation of class I and class II butterfly-shaped plastic zones by further studying the morphological evolution law of plastic zones in the deep dynamic pressure roadway and defined the malignant expansion and criticality of plastic zones.…”