Research on the Calculation Method of Tunnel Active Support System Based on the Total Safety Factor Method
The concept of tunnel active support with prestressed anchor rods(cables)as the main support compo-nents is increasingly widely applied.However,the selection of support parameters for active support systems still primarily relies on engineering analogy or empirical values,lacking a quantified calculation method to guide design.Based on the total safety factor method for tunnel support structure design,this study proposes a calculation method for the safety factor of the active support system including prestressed anchor rods(cables)and a design method,and it analyzes and compares the differences of safety factors and deformation control between active and passive support systems.Furthermore,to explore the deformation coordination relationship between the anchor rod(cable)system and the surrounding rock,this study introduces a support system selection and design process based on deformation coor-dination control,considering the compatibility of deformation capabilities between the anchor cable system and the surrounding rock.This can provide theoretical guidance for the quantitative design of tunnel active support systems.
Active support systemTotal safety factor methodPrestressed anchor rod(cable)Yielding supportDe-formation coordination