Borehole Camera Technology for Measuring the Relaxation Zone of Surrounding Rock. Mechanism and Application
JING Hong-wen
LI Yuan-hai
LIANG Jun-qi
YU De-cheng
Abstract：A panoramic borehole camera technology (BCT) and digital image processing method was developed by constructing a system composed of hardware and software. The technology was used for measuring the relaxation zone of surrounding rock with the borehole camera. The hardware consists of a mini CCD camera and a high-pressure sealed magnetic compass that is used for camera positioning. The software includes real-time image monitoring and a processing program that includes the procedure for analysis of the relaxation zone. The roundness of cracks in the boreholes is taken as the index for identifying the relaxation zone. The system was used to measure the relaxation zone of a deep roadway in the Qiwu coal mine of Shandong province. The distribution of the relaxation zone around the roadway was obtained. The results show that the thickness of the broken rock zone varies with the measuring position within a cross section of the roadway. The reliability of the measuring method was tested and verified by comparing the data from BCT with those measured by an ultrasonic method: The difference is less than 3.5%. The system provides a new method for the measurement of the relaxation zone when engineering deep underground.
Keywords：borehole camera gechnologyracksindex of roundnessbroken rock zoneimage
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 645-649,669 )