Combined support technology for main roadway passing through goaf: A case study

Abstract

AbstractControlling the surrounding rock of the main roadway passing through a goaf during the reconstruction and expansion of a merger and reorganization mine is a common challenge in underground mining practices. In this study, a combined support technology of roof “anchorage‐mesh‐shotcrete” and a double‐H‐type space frame structure for a main roadway passing through a goaf was studied using field investigations, theoretical analysis, and engineering practice. It was observed that the main roadway control difficulties lie in the strongly mining‐induced roof strata in the early stages, with collapsed gangues not connected to an unsupported roof, large goaf sections, and multiple superpositions of surrounding rock stress fields with complex distributions. Based on the results, a double‐H‐type space frame structure support system comprising a “reinforced concrete pillar + reinforced concrete longitudinal beam + cross steel I‐beam” was constructed. This provided strong pillar support, enhanced the shock resistance of the roof, improved the bending and lateral pressure resistances of the frame structure, and produced airtight spaces for the main roadway. Accordingly, a “double systems” support scheme was designed. The results of the engineering practice indicated that the deformation of the goaf roof and force of the supporting structure were controlled within a safe range, meeting the requirements for mine ventilation, pedestrians, and haulage. Consequently, the surrounding rock control problem for the main roadway passing through the goaf was effectively solved, and theoretical and technical bases were provided for the stability control of a roadway passing through a goaf under similar conditions.