TUNNEL BACK-FILLING APPARATUS

PROBLEM TO BE SOLVED: To provide a tunnel back-filling apparatus which can not only shorten an excavating period but also easily control its position. SOLUTION: The tunnel back-filling apparatus carries out back-filling of a tunnel E while removing an existing tunnel structure A. The apparatus includes a triple cylindrical front trunk 2 consisting of an external cylinder 11 for preventing cave-in of the natural ground B, an intermediate cylinder 12 equipped with a cutter head 7 at the front end thereof, and an internal cylinder 13 shielding the interior and exterior of the apparatus. A slurry chamber 26 is formed by using a gap defined by the intermediate and internal cylinders 12, 13, and a guide 27 is arranged at the center of the external cylinder 11. A gripper 45 which can be press-fitted to the existing tunnel structure A is slidably fitted in the guide 27, and a jack 46 for frontward and rearward moving the front trunk 2 is stretched across the guide 27 and the gripper 45.