Indonesia Conference Directory

The geological condition of Indonesia consisting of various geological formation units, one of which is volcanic products with tropical climate with different characteristics, allowing the discovery of rock-mixed soil media conditions such as the construction of the Sumedang toll road tunnel, where the media has an average Vp 2015m / s and CF1.1403 which are included in the soft rock category (category D II) . The condition of the media can cause various instability problems when doing tunnel excavation, especially the collapse of the crown with a deformation value of 65.6 cm. Therefore, an initial reinforcement system is needed in the form of forepoling with fillers less than 5 meters in length and the distance between forepoling 0.5-0.8 m before excavation to increase the shear strength of the soil / rock on the crown so as not to collapse.