缓冲垫层对锚杆托板动静载力学特性的影响研究

Study on the influence of buffer cushion on dynamic and static load mechanical characteristics of anchor bolt support plate

为揭示缓冲垫层对锚杆托板动、静载力学特性的影响,从而为冲击地压巷道支护中缓冲垫层的选取提供理论依据,在实验室专门搭建缓冲垫层与托板组合结构冲击实验台,测试5种组合结构的静、动载力学性能,利用高速摄像仪捕捉组合结构的变形破坏过程,分析冲击能量、缓冲垫层材质、厚度等参数对托板结构力学响应的影响规律。研究结果表明:缓冲垫层会显著影响托板结构的静、动载变形破坏形态,具有一定延性和变形能力的缓冲垫层能提高托板结构的静载承载能力。缓冲垫层材质和厚度对冲击载荷的缓冲吸能效果影响显著,延性、变形能力大的缓冲垫层吸收冲击能量更多,能降低托板结构变形程度,反之亦然。刚度越低、变形量越大及厚度越厚,组合结构的冲击力峰值越小,托板变形量越小;而刚度大、脆性强的缓冲垫层对组合结构的冲击力峰值影响不大,但会显著增加托板的变形量。从托板变形量来看,5种组合结构吸能效果优劣依次为泡沫金属+托板、木材+托板、橡胶+托板、混凝土+托板和托板。

In order to reveal the influence law of buffer cushion on the dynamic mechanical response of bolt supporting plate structure,and thereby provide a theoretical basis for the selection of buffer cushion in rock burst roadway support,a special impact test device for combined structure of cushion and supporting plate was built in the laboratory,and the static and dynamic mechanical properties of five kinds of composite structures were tested.The deformation and failure process of composite structure was captured by high-speed camera,and the effects of impact energy,cushion material and thickness on the mechanical response of supporting plate structure are analyzed.The results show that the cushion can signi-ficantly affect the static and dynamic load deformation and failure mode of the supporting plate structure.The cushion with certain ductility and deformation capacity can improve the static load bearing capacity of the supporting plate structure.The cushion material and thickness have a significant impact on the cushioning and energy absorption effect of impact load.The cushion with large ductility and deformation capacity absorbs more impact energy,which can reduce the deformation degree of supporting plate structure,and vice versa.With the lower stiffness,the greater deformation and the thicker thickness,the impact force peak value of the composite structure and the deformation of the supporting plate will be smaller.The cushion with high stiffness and strong brittleness has little effect on the peak impact force of the composite structure,but it will significantly increase the deformation of the supporting plate.From the viewpoint of the supporting plate deformation,the energy absorption effects of the five kinds of compo-site structures rank in foam metal+supporting plate,wood+supporting plate,rubber+supporting plate and concrete+supporting plate.