预应力中空注浆锚杆锚固机理与参数分析

Analysis on anchoring mechanism and parameters of prestressed hollow grouting bolt

基于理想弹性载荷传递函数关系,建立了力学数学模型,探讨得出预应力中空注浆锚杆锚固段的力学平衡微分方程。通过分析锚杆和注浆体之间共同作用的效果,得出预应力中空注浆锚杆的轴向荷载和界面剪应力的分布函数,并且对影响锚固体锚固效果的参数进行了分析。结果表明:增加锚杆和注浆体的直径可以很好的增强支护效果,但是单一增大锚杆的长度并不能达到更好的支护效果;经由过程计算和分析,得出事先在锚杆上施加预应力,能更好地限定围岩变形。

A mechanical model was established based on the ideal elastic load transfer function, and the mechani-cal balanced differential equation of anchoring segment on the prestressed hollow grouting bolt was deduced. Through analyzing the effect of interaction between bolt and grouting body, the distribution function of axial load and interface shear stress on the prestressed hollow grouting bolt was derived, and the parameters influencing the anchoring affect of anchorage body were also analyzed.The results showed that increasing the diameter of bolt and grouting body can enhance the supporting effect well, but the better supporting effect can＇t be achieved by only in-creasing the length of bolt.Based on the numerical calculation and analysis, it was concluded that the prestress im-parted on the bolt can better constraint the deformation of surrounding rock.