Application of wide-space blasting technology during the excavation in large-section hard rock tunnel
During the tunnel excavation works in Tailrace Tunnel of Karuma HPP Project,Uganda,in order to solve the problems of large section hard rock tunnel excavation,such as large number of bore holes,long drilling time and slow construction progress,we adjusted the idea of tunnel blasting layout in actual construction,changed the traditional layout method,and proposed the concept of ＂wide-space bore hole layout method for tunnel excavation＂.Through a series of blasting tests,we successfully reduced the number of top bench excavation bore holes in the original design from 246 to 181,effectively reduced the number of bore holes and achieved rapid excavation.The test shows that in the excavation of large section hard rock tunnel,by using wide-space blasting technology,the number of bore holes was reduced by 26.42%,effectively shortening the drilling time and speeding up the single cycle of excavation,finally achieving a good result of 230.2 m(excavation section 102.02 m2)of monthly progress on one side of the top bench excavation of the main tunnel.
tunnel excavationhard rockwide-space disposal bore holepilot study
万方数据
维普
