TUNNEL FACE MONITORING SYSTEM APPLYING DBF-BASED 79GHz HIGH-SPEED IMAGNG RADAR

Abstract

 In order to prevent fatal accidents caused by falling concrete skin and rocks in tunnel construction, authors developed of tunnel face monitoring system applying a millimeter-wave, 79GHz high-speed imaging radar. The radar is able to detect the minute deformation and vibration of tunnel face in non-contact.

 In this paper, authors considered the precursors of face and rock fall as minute movements of the surface and changes in frequency charecteristis due to drilling work, etc., and conducted fundamental experiment using concrete panel test pieces to detect that would be captured by the radar.

 Performance and availability were confirmed through a fundamental experiment and a distributed vibration measurement. Also, authors described the problem in coordinate transformation that coordinate from the measured value obtained by the radar to the face when applying the radar to the tunnel face, propose a simple conversion method as a countermeasure.

 The trial measurement with the simple conversion method in the actual tunnel is conducted, and the result is confirmed.