Shallow-burying exposure construction method applicable to hard rock tunnel with extra large fracture surface

• Main Authors: YAO DACHUANG, MENG YONGLI, YU CHENG, DU JIANGSHAN, ZHANG YUKUN, XING BIAO, WEI ZHIYUAN, FENG JIMENG, CHEN WENYIN
• Format: Patent
• Language: Chinese; English
• Published: 26.10.2018
• Subjects: EARTH DRILLING; FIXED CONSTRUCTIONS; GALLERIES; LARGE UNDERGROUND CHAMBERS; MINING; SHAFTS; TUNNELS

The invention provides a shallow-burying exposure construction method applicable to a hard rock tunnel with an extra large fracture surface. The excavated volume of soft soil exposed on the earth surface is compared with that of a first excavation part formed by means of a CD method, cover arch construction is conducted if the excavated volume of the soft soil is higher than that of the first excavation part, a benching tunneling method is adopted for excavation, and if the excavated volume of the soft soil is not higher than that of the first excavation part, the CD method is adopted for excavation; according to the CD method, the whole process is divided into four steps for excavation, correspondingly there are four parts to be supported, and backfill of the ground needs to be conductedin time after a second excavation part is completed; according to the benching tunneling method, the whole process is divided into three steps for excavation, and backfill of the earth surface is conducted after excavation of