动态围压约束煤矸石混凝土巷旁墩柱增阻大变形机理研究

巷旁支护结构强度/刚度与变形能力之间的相互匹配是深部沿空留巷成功的关键。本研究提出一种兼具“柔性让压”和“高强支护”力学特性的经济环保型支护结构，即钢骨架聚乙烯纤维增强塑料（简称SRPE）复合管约束煤矸石混凝土巷旁墩柱。为进一步明确煤矸石混凝土在SRPE复合管提供的动态围压约束条件的增阻大变形机理，本研究拟采用实验室试验、理论分析和数值计算相结合的研究方法，以常围压条件下煤矸石混凝土的应力应变关系为切入点，采用不同约束材料提供动态围压环境，研究动态围压条件下煤矸石混凝土的力学特性。根据常围压和动态围压条件下约束力等效转换模型，建立动态围压条件下煤矸石混凝土本构方程。在此基础上，研究SRPE复合管约束煤矸石混凝土巷旁墩柱在沿空留巷条件下的力学响应特征，揭示新型墩柱结构的变形协调机制。研究成果有助于掌握动态围压条件下煤矸石混凝土的力学特性，为新型巷旁墩柱结构在深部沿空留巷的应用奠定理论基础。

The balance between the strength/stiffness and deformation capacity of the gob-side support is regarded as a key component to the success of gob-side entry retaining technology in deep mining. The present research proposes a novel hybrid tubular column obtaining the combination behavior of “flexible deformation” and “high strength/stiffness” which is environmental and cost-effective. The novel column consists of an outer tube made of skeleton polyethylene fibre-reinforced plastic (i.e. SRPE) and an infill made of coal gangue concrete. Compared with market available tubular standing supports, the SRPE composite tube confined-coal gangue concrete exhibits the obvious strain-hardening behavior with large deformation capacity. In order to better understand the mechanical characteristics of the novel column, the combination of laboratory tests, theoretical analysis and numerical modelling will be conducted. Both the failure mode and confining mechanism of coal gangue concrete under constant/dynamic confining pressure will be investigated respectively. The equivalent transformation model of the confining force under different conditions (i.e. constant confinement and dynamic confinement) will be used to set up the constitutive equation for coal gangue concrete under the confinement provided by SRPE composite tube. Then, the behavior of SRPE composite tube-confined coal gangue concrete tubular column in real application (i.e. gob-side entry retaining) will be explored through the coupling of FLAC and PFC software to further evaluate the deformation mechanism under different loading conditions. The expected results from the present research can deepen the understanding of the mechanical properties of coal gangue concrete under dynamic confining pressure. Meanwhile, the proposed novel hybrid tubular column can enrich the possible selections for gob-side entry retaining in deep mining.