ASSESSMENT OF ANCHORING QUALITY AND DEFECTS OF MORTAR BOLT BASED ON WAVELET ANALYSIS

It is a key for rock-soil anchor used in deep excavation support to assess anchoring quality by nondestructive testing method based on reasonable analysis of dynamic response curve of acceleration signal received by dynamic data recorder． So there different kinds of anchor models were designed for wholly grouted mortar bolts which had no defect，one defect，and two defects．Received the response curves of acceleration signals by tapping test，reappeared in computer by Matlab，then the vibration waveforms could be analyzed and contrasted by wavelet analysis，so the inner connexion between the vibration waveform and every model was established，which could reflected the three measure parameters，i． e． the period of a single cycle，the frequency value of time-frequency spectrum，and the deadening of energy． The results showed the rules of dynamic responses could be correctly reflected by the time domain waveforms and time-frequency spectrum for different anchor qualities． that were the faster of stress wave deadening in bolt，the better of anchor quality．