| The detection in anchorage quality of rock bolts was experienced devastating testing to non-destructive testing. With the development of modem nondestructive testing technology, the pull out testing replaced by non-destructive testing. This method avoid case some potential flaw makes the quality of construction can't reach design requirement and do a lot of damage in project, also make real-time detection and evaluation of rock bolts stability possible. The paper based on stress wave testing theory conducted in the theory on anchorage quality of rock bolts; using signal processing methods to analyze the testing signal, get the characteristic signal; based on MATLAB to developed the signal analysis software, realizing anchorage quality intelligent evaluation; in a coal mine, through a small field test, show the reliability of signal analysis software. The paper do some major research as follows:1. First introduce research on theory of bolt support and in different periods anchoring force situation. By analysis on theory of stress wave spreading,do research on transmit regulation of stress wave, and summarized energy attenuation and distribution rule. These results provide an important academic gist in detection on anchorage quality.2. Anchorage system quality can be estimated by valid bounding length, ratio of amplitude, attenuation coefficient, primary frequency, ratio of frequency and dynamic stiffness six parameters. The "consolidating wave speed" in the anchorage structure reflect the relationship between the bond strength and the rock bolt, from another aspect reflection anchorage quality.3. Wavelet analysis, multi-differentiate analysis, wavelet packet analysis, and some other signal processing methods have been used to analyze the testing signal. Base on correlation analysis theory, proposed a method to identify bottom reflection signals.4. According to the stress wave propagation theory and signal analysis theory, based on MATLAB, produced nondestructive testing signal analysis software, realizing anchorage quality intelligent evaluation, also improve analysis precision and interface visualization.5. The field test results show that it is feasible to use the method to measure the anchorage quality of rock bolts, and make real-time evaluation to be possible. |
