| Bolts are widely used for supporting in coal mines, it has such an impact on the existing support by the mining dynamic laod and blasting dynamic load, and has an urgent need to study the micromechanical properties of bolts under the dynamic laods. Based on this, the paper study the mechanical properties model test of end-anchored grouting bolts in the axial direction under the small strain with high frequency dynamic loads,equivalent to large strain with low frequency dynamic load. It adopts these means, what it using the indoor model test as the main mean and using the theoretical analysis, and FLAC3D nonliner dynamic simulation analysis, and BP artificial neural network predictive analysis as the supplementary means, to carry out the research. The research results show that it gets repeated loading and unloading mode effect frequency 430.882Hz, cycle 0.0023s nonlinear stress waveform function and velocity waveform function, to lay the foundation for the numerical simulation of writing a program. Through the sensitivity factors analysis, it gets the binary linear regression model function of bolt shear strength between bolt diameter and bolt length, the influencing factors of shear strength with bolt length is larger than that of shear strength with bolt diameter. The axial stress distribution of end-anchored grouting bolts own a transportation transitivity, anchoring bolts axial peak stress occurs in the middle section of effective anchorage length of bolts. By nonlinear dynamic simulation analysis, it results in a radius of 40mm round plastic yield shear zone and has an circular area is the shear yield failure to produce an inner radius of 40mm, outer radius thickness of about 10mm to 50mm annular shear stress yield plastic failure zone at the interface between anchoring free section and anchoring segments. It has certain reliability that the BP artificial neural network is used for predicting the maximum bolting force of the end-anchored grouting bolts. |
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