Experimental Research Of Anchors Bonding Mechanical Properties Under Transverse Harmonic Loads

With the wide application of coal mine anchor bolt supporting engineering,It is an urgent need to study the micro mechanical properties and the adhesion variation of bolt under dynamic load as a consequence of the effect of the mining load and blasting load on the existing bolt supporting.Based on practical engineering,on the spot,the paper mehitored,in the process of axial force variation and load of blasting vibration,the vibration information of environment rock on the working condition about anchor bolt.The detection results showed that the axial force of the bolt along with the age increased gradually and then became stable,that axial force was approximately one third the strength of designed anchoring force and that rock around the anchor represented vibration signs on blasting condition.The indoor test results showed that bond force decayed fastest when the bolt was influenced by transverse harmonic vibration load-vibration frequency of 40Hz-under working state and that the relation between change rate of bond force,amplitude of vibration and time on the condition of 40Hz20s transverse vibration loads was acquired,which provided access to predicting the impact of vibration loads on adhesive force at different ages.Two factors,amplitude of vibration and maintenance period,of which maintenance period was more sensitive,both exerted an influence on adhesion decay of the new assembled bolt.The bolt pulling test,under transverse harmonic load,suggested that theshear stress of the bolt moved from the bottom to the central region and that the peak value of shear stress appeared in a position-the one quarter and three quarters of the anchored end of the bolt.Though the analysis of sensitivity factor about length and diameter of the anchor,it suggested that the length sensitivity was greater than the diameter sensitivity.The results,based on FLAC3D simulation software,with indoor experimental parameters,fitted roughly with that of indoor test and the development situation of the plastic zone in the process of drawing was obtained...