LASER RANGEFINDER-BASED MEASUREMENT WHILE DRILLING DEVICE AND METHOD FOR DETERMINING ROCK MASS GRADE OF TUNNEL ROOF

摘要

Provided are a laser rangefinder-based measurement while drilling device and method for determining a rock mass grade of a tunnel roof. The device comprises a pulse-type laser rangefinder (1), a roof reflector (2), a tightening device (3), and an individual roof bolter (4). The individual roof bolter (4) is vertically provided at a road floor (6) to vertically insert a bolt into a tunnel roof (5). The pulse-type laser rangefinder (1) is provided at the individual roof bolter (4) by means of the tightening device (3) and points to the tunnel roof (5). The roof reflector (2) is provided at the tunnel roof (5) in a location corresponding to a location of the pulse-type laser rangefinder (1). To determine a basic mass grade of a roof rock, the present invention incorporates with a drilling process in anchorage support technology, uses a pulse-type laser rangefinder and a roof reflector to measure advancing depths of a hole drilled in the roof at fixed intervals to obtain an advancement-drilling rate curve associated with the drilled hole, and performs comparison and analysis on the curve and an established drilling rate standard library for rocks having mass grades of I-V to obtain basic mass grades of respective rocks within a range of the drilled hole, thereby realizing a real-time and continuous measurement while drilling operation with respect to a roof in a tunnel construction process. The present invention is applicable to a situation of significant changes in hardness of a rock layer of a tunnel roof.