Study On Mechanical Behavior Of Retrievable Anchor In Geotechnical Engineering

Bolt is widely used in our country's hydropower industry,transportation industry,underground space and mining and coal mining industry.But traditional bolt can not be recovered and reused timely,so recoverable bolt gradually rises.On one hand,it solves the reinforced pollution problems from the underground and saves the cost.But on the other hand,we know little about its mechanical properties,anchorage mechanism,work character.In this paper,based on the load transfer mechanism,recoverable bolt is analyzed in both theory and numerical simulation.The details are as follows:(1)Compared with traditional bolt's structural and mechanical properties,the pressure type recoverable bolt is taken as an example for discussing its component size.(2)Pressure type recoverable bolt,for example,based on elastic mechanics and soil mechanics theory and radial deformation coordination conditions between the anchor body outer and the surrounding rock,the distribution formulas of stress along the bonded length of pressure type recoverable bolt are derived.Compared with existing theoretical results,the formulas are proved to be more practical.(3)To analyze influence factors of pressure type recoverable bolt anchorage performance,curves with different related parameters are analyzed to get corresponding conclusions.(4)Using FLAC3 D for numerical simulation with different related parameters,the theoretical sollution is verified.This innovation point in this paper can be summarized in three aspects:1)The theoretical equation of the distribution of normal stress and shear stress of recoverable anchor segment is established.2)According to whether the cohesion within rock-soil body is zero,the concept of " effective anchorage length" and " quasi anchorage length" is proposed,and the corresponding calculation formula is obtained.3)The influence of relative parameters such as elastic modulus ratio,poisson ratio,anchorage radius,internal friction angle of rock-soil body on the stress distribution of anchorage segment is discussed.