Coupling the acoustic emission probe with the specimen is the key link in the measurement of preexisting stress of the rock specimen by Kaiser effect.
以凯瑟效应测量岩石试样先存应力，声发射探头与试样的耦合是其重要环节。
3
The initial stress is one of the most important parameters for the design of underground rock engineering, and hydro-fracturing method is a robust technique for stressmeasurement in deep rock mass.