Abstract: Constant resistance and large deformation bolt has the excellent characteristics of high constant resistance force, large deformation and high energy absorption, and is thus widely used in the reinforcement and monitoring of roadway, tunnel and slope engineering. A nonlinear mechanical model of constant resistance and large deformation bolt is established based on the analysis of the characteristics of constant resistance anchor. The model could unify the rising section and the stick slip section of constant resistance force, and can more completely describe the mechanical behavior of the constant resistance and large deformation bolt. Moreover, the dimensionless method is used to analyze the four parameters ?, ?, ?d and f, which affect the mechanical behavior of the constant resistance and large deformation bolt, and the influence characteristics of each parameter on the mean value of constant resistance force, amplitude, vibration period and main vibration frequency of the system in the stick-slip phase are obtained. Finally, the nonlinear model is verified based on the finite element numerical simulation method, and the accuracy of this nonlinear mechanical model is proved. Meanwhile, the influence characteristics of the constant resistance body bulk modulus, casing bulk modulus and tensile speed on the constant resistance stick slip behavior of the constant resistance and large deformation bolt are researched. The results could provide a theoretical basis for the subsequent optimization design and engineering application of the constant resistance and large deformation bolt.

Key words: constant resistance and large deformation bolt, nonlinear mechanical model, stick slip behavior, friction vibration, numerical simulation