井壁无破损检测的研究

Non-destructive testing of Shaft Lining

用超声波探测技术对邯邢九龙口风井的喷射混凝土工程质量、抗压强度、厚度以及井壁后围岩的松动范围进行了检测,取得了较好效果。一、超声波检测的原理声能是机械能的一种形式,声在介质中以波动形式传播。超声波检测是由岩体超声波检测仪的发射机发出高频电脉冲信号,由发射换能器将这种电信号转换成机械振动,并将振动传递给检测介质,再由接收换能器把弹性波振动转换成电信号送入接收机。

the ultrasonic testing is to obtain the acoustic velocity of the medium. High frequency elec- trical signals from the ulrasonic transmitter are converted into mechanical vibrations by trans- ducer in the transmitter, which are transmitted to concrete and the surrounding medium, and then the elastic waves are again converted into electrical signals by the transducer in the receiver, and the wave form is shown by a oscilloscope. Owing to the difference of acou- stic velocities in concrete and surrounding rock, and in loose and unloose rock, the thick- ness and strength of concrete lining and the extent of loosen rock may be detected. The results of ultrasonic testing of the sprayed shaft lining in jiulongkou ventilation shaft in Handan and Xingtai are as the following: The average thickness of shaft lining 256.9 mm; the average strength of concrete 285.7Kg/ cm^2, 96％ of the lining has reached or ex- ceeded the design strength, and only 4% is below the design strength; the average extent of loosen rock is 543.7mm.