关键词: 托顶煤巷道, 锚索梁支护, π型钢梁, 高强支护

Abstract: Addressing the substantial stability challenges in the expansive section top-coal roadways of the No. 3 coal seam in Li Lou Coal Mine, this research centers on the conveyance gateway of the 1300 working face. Employing a synergistic approach of numerical modeling and empirical laboratory testing, the project aims to engineer high-strength structural components vital for maintaining the integrity of the surrounding strata in these roadways. The initial phase involves the conceptualization of a robust protective support system tailored for top-coal roadways. This is followed by a comprehensive assessment of U29 type steel anchor beams and expandable framing systems through a combination of simulation studies and controlled laboratory experiments. Results indicate a marked superiority of π-type steel over the U29 steel variant, which had exhibited an escalated deformation of 275%, in terms of deformation resistance, maintaining near-constant deformation levels under stress. The load-bearing efficacy of π-type steel beams surpasses that of U-shaped steel by an average of 4.7% under vertical load conditions and 12.0% under inclined load scenarios. Additionally, when subjected to vertical and dynamic impact loads, π-type steel beams exhibit a 5.0% enhanced load-bearing capacity. The study observes an increase in the maximum deformation of the arch structure with its height and width, yet finds no significant relationship between the width-to-height ratio and arch deformation, indicating a preference for arches with rounded corners. The impact of vertical loads on arches is pronounced; more uniform force distribution correlates with minimized arch deformation. Under eccentric loading, the arch's upper central region remains the focal point of maximum deformation, which diminishes as the central load is reduced, and significant horizontal displacement is observed at the support legs, especially around the curved shoulder areas. Structural designs featuring four and five segments significantly outperform the traditional three-segment approach. Strategically placing nodal points at the arch legs proves more effective in facilitating the overall stress accommodation of the arch. This research contributes valuable theoretical insights for designing tunnel supports under analogous geological settings.