A Study on the Evaluation of Necessity for the Support in Case of Excavartion of the Transport Drift at Danyang Site

단양지역의 운방갱도 굴착시 갱도 지보의 필요성 판정에 관한 연구

In order to evaluate the necessity for the support during the excavation of the transport drift and use the data for design applications, laboratory testings of mechanical properties of rock samples and engineering rock mass classifications on this study site were performed. The values of RMR and Q-system are 68 and 11.8, respectively. Since these results were evaluated as good, this rock mass were determined to be unsupported. Full face excavation method was determined to be suitable for excavating this drift. In case of excavation, smooth blasting techniques must be carried out at the wall rock and the crown. However, considering the blast vibration etc. that have an effect on the surrounding rock mass, approximately less than 9kg of explosive charges per blast should be maintained.