The study of nondestructive testing of rock bolts based on PNN and wavelet packet

Anchoring technology is widely used in slope, tunnels and underground engineering. However, the quality of rock bolts is still a hot problem difficult to solve. Considering the shortcoming of pull-out testing, defect recognition in a nondestructive way is necessary. Decomposing the signals obtained by bolt quality detector with wavelet packet; extracting energy feature by wavelet packet energy spectrum; converting the normalized energy eigenvector as input of probabilistic neural network. With a higher accuracy than RBF, the PNN model can provide a reference for recognition defects of rock bolts in engineering without destruction.