THE BLASTING METHOD OF TUNNEL UNDER STOPPING BY VERTICAL amp; HORIZENTAL BENCH DRILLING : TVH - BENCH

摘要

The present invention relates to a blasting method by the tunnel lower cross-section hybrid drilling method, and aims to shorten the tunnel lower cross-section excavation air and reduce the excavation construction cost. The blasting method according to the tunnel lower end surface mixed drilling method according to the present invention includes a first step of drilling a plurality of vertical holes 41 so as to be close to the tunnel scheduled line at the periphery of the tunnel; A second step of blasting and blasting the central portion of the lower end surface of the tunnel by blasting the vertical hole drilled through the first step; When viewed from the front through the second step, each of the left and right sides of the tunnel sidewall portion in the horizontal expansion hole 43 inwards from the membrane surface inwards, and the adjustment blast hole 44 along the tunnel scheduled line of the tunnel sidewall portion A third step of drilling; The fourth step of simultaneously blasting the horizontal expansion hole and the control blasting hole punctured through the third step. In the first step, the inclined hole 42 is drilled at an angle extending downward to the vertical hole and the tunnel sidewall portion, and the blasting is performed in the second step.