关键词: 隧道工程, PVC管聚能爆破, 超欠挖, 现场试验, 水平砂泥岩

Abstract: Taking Duanjiaping tunnel of Menghua railway section as an example, the forming characteristics of horizontal sandy mudstone tunnel by blasting were analyzed. The PVC pipe cumulative blasting method was put forward and the PVC pipe cumulative blasting device was developed. The expected blasting and forming effect was achieved by using PVC pipe cumulative blasting method. When the direction of PVC pipe cumulative energy structure was basically perpendicular to the horizontal rock layer bedding structure, it was necessary to reduce the blasting hole spacing. The PVC pipe cumulative blasting method can better control the overbreak and underbreak amount of the tunnel in horizontal sandy mudstone stratum, and most of overbreak amount is controlled within 15 cm, and the maximum overbreak amount is reduced by 78.8%. At the same time, if the factory produces PVC pipe energy-accumulating structure in large scale, the time and materials will be saved better, and the work efficiency will be improved.

Key words: tunnel engineering, PVC pipe cumulative blasting, overbreak and underbreak, field test, horizontal sandy mudstone