Research on the Evolution Law of the Plastic Zone and Control Technologies for Surrounding Rock in Floor Roadway Influenced by Mining Activities

ABSTRACT This study addresses the challenges of deformation failure and the difficulty in controlling the surrounding rock in the 2453 floor roadway of a coal mine in Hunan Province, influenced by mining activities. Conducting an in‐depth investigation into the evolution law of the principal stress and stability control technologies for the surrounding rock of the floor roadway under the influence of mining. The research employs a combination of on‐site investigations, laboratory tests, numerical simulations, and industrial trials. The results indicate that high horizontal tectonic stress and the characteristics of soft rock can easily lead to significant deformation of the surrounding rock in the roadway. By monitoring the principal stress in each part of the surrounding rock from the excavation of the 2453 floor roadway to the completion of upper coal seam mining, we obtained the evolution of the principal stress in the surrounding rock influenced by mining activities. During the mining process, the plastic zone in the “butterfly leaf” region of the surrounding rock in the roadway exhibits malignant extension; however, the depth and extent of the plastic zone on the sides remain largely unchanged. Based on this, a comprehensive support technical scheme is proposed, featuring “full‐face high pre‐tightening force bolt supporting + enhancing the support with long anchor cables at the key part of the plastic zone in roadway + grouting” as the main supporting body, complemented by “metal mesh + shotcrete” as auxiliary support measures. On‐site monitoring has shown that the new support scheme more effectively controls the stability of the surrounding rock.