A pin for measuring a tunnel convergence and crown settlement

摘要

The present invention relates to a pin for measuring the internal hole displacement and the tip displacement of a tunnel, wherein a taper screw is formed on a side of the anchor bolt inserted into and fixed to the tunnel wall, and a thread is formed on a portion of the anchor bolt exposed to air. And it can raise the construction convenience of an elastic part. In addition, the anchor bolt can be stably fixed to the tunnel inner wall by appropriately selecting the length of the anchor bolt according to the rock type of the tunnel inner wall. In addition, by adding a cover surrounding the entire elastic spring to prevent foreign matter from penetrating into the elastic spring, it is possible to prevent the elastic spring from decreasing. In addition, it is possible to prevent the target from being embedded by the shotcrete by appropriately selecting and constructing the length of the elastic portion in consideration of the shotcrete placing thickness. In addition, by adopting the bi-directional folding target, it is possible to prevent the loss of the target due to scattered debris, equipment operation, etc. to secure the initial measurement value early.