Research On Nondestructive Testing Technology Of Rock Bolt Quality Based On Ultrasonic Method

With the continuous improvement of China’s anchor support theory and design methods,new support materials and support equipment have been successfully developed and put into use,and a huge role in infrastructure,such as bridges,dike dams,coal mines,etc.,It is more and more wide.In the process of using the bolt,because the actual project is inevitably affected by the complex environment,it is difficult to control the quality of the project,which may lead to the occurrence of engineering quality problems.In the case where the anchor is used,whether the anchor anchoring construction plays a reinforcement to not only affect the overall quality of the facility engineering,but also affect the lives and property of our people,there is a need for the construction quality of the anchor anchoring to test.The current non-destructive detection method is mainly based on wave of stress and ultrasound,and is comprehensively consolidated by the analysis and processing of digital signals collected by the collected echoes.Among them,the stress wave method needs to manually use the hit hammer when used as an excitation,and there is a certain person’s error and should not detect a deeper anchor.The ultrasonic method does not need to use a knocking hammer,so it is more convenient than the stress wave method.This article designs a high performance bolt quality nondestructive testing system by ultrasonic nondestructive testing technology and neural network technology,which can not only detect the length of the target bolt and the degree of bonding between the bolt and the anchoring medium(It is usually called grouting compactness or mortar saturation),but also can detect the crack defect type of bolt and extract the characteristic data of corresponding defect.The main work of the paper is the following:(1)In-depth research on the theoretical basis of non-destructive testing of bolt quality based on the ultrasonic method,and through the relevant knowledge of actual bolt engineering quality testing,put forward a design of a non-destructive testing system suitable for bolt quality analysis,including the hardware equipment of the lower computer and the software server of host computer two parts.(2)According to the proposed system design plan,combined with digital circuit technology,analog circuit technology,embedded technology and related knowledge of wireless communication technology,the design of the hardware echo acquisition equipment is completed.The function of each circuit is introduced in detail.At the same time,the driver program of each module was written,the corresponding graphical upper computer software was designed,and the control and operation process were analyzed in detail.(3)A neural network-based classification method of bolt grouting compactness,classification method of bolt crack defects,and feature extraction method of corresponding defect types are proposed.(4)Some bolt test models were made,and the experimental models and the proposed method were verified through experimental tests.The results proved that the designed system can classify the grouting compactness and crack defects of the bolts.In addition,the extraction error of anchor bolt defect feature data is less than 2%,which has high accuracy of anchor bolt defect classification and defect feature extraction,which improves the reliability and accuracy of bolt quality inspection,and can be used for nondestructive quality inspection of rock bolt.Provide preliminary useful reference information.