Development and application of stability dynamic monitoring andmeasuring device to gas drainage borehole

In order to real timely and dynamically monitor and measure the stability of the deep gas drainage borehole, a stability dynamic monitoring and measuring device of the gas drainage borehole was independently researched and developed and the device was mainly composed with a host loading structure, high sensitive stress and strain gauges, rapid connected rod and precision stress and strain gauges. The device could collect different angle geostress and collect the deformation data of the borehole. The host loading mechanism with different material quality could realize the stability reinforced effect of the borehole. The site measured result s showed that the deformation curve of the borehole could roughly be divided to three stages, including the rapid deformation stage, slow deformation stage and basic stable stage. A obvious inflexion individually existed between the rapid deformation stage and the slow deformation stage and between the slow deformation stage and the basic stable stage. In the different diameter boreholes, the same depth and deformation amount would be increased with the diameter increased. In the same diameter boreholes, the different depth and deformation in the shallow depth would be higher than the deformation at the deep depth. The deformation of the gas drainage borehole would be affected to the gas drainage operation conducted in a certain degree. The device with a good practicability and reliability could provide a new means to real timely and dynamically monitor and measure the stability of the gas drainage borehole.