Internal disease detection methods are mainly

Tunnel internal diseases mainly include: lining thickness is insufficient, behind the existence of voids, behind the lining rich in groundwater or surrounding rock weakening, insufficient strength of the concrete and not compact, etc. These internal diseases are easy to induce cracking, water seepage, spalling, peeling and other structural apparent diseases, and even cause collapses, surges and other disasters and accidents, which seriously jeopardize the structural and traffic safety. Therefore, it is crucial to carry out the detection of internal tunnel diseases to grasp the technical status of the structure and ensure operational safety.

Traditional tunnel disease detection methods, core drilling method can detect tunnel internal disease, but it is bound to cause secondary damage to the tunnel structure, which may induce sudden disasters, and the detection efficiency is very low, and can not meet the needs of a wide range of maintenance and inspection. For this reason, ground-penetrating radar, ultrasonic detector, rebound meter and other non-destructive testing instruments are trying to be applied to the tunnel internal disease detection.

Ground-penetrating radar and ultrasonic detection technology has been widely used in tunnel nondestructive testing, infrared temperature detection technology has also been applied to some extent. Among them, ground-penetrating radar can be used to detect the thickness of the lining, behind the cavity, and can determine whether there is a large-scale underground water body behind the lining; ultrasonic is mainly used to detect the strength of the concrete, the lining and the initial support is close to.