EVALUASI TINGKAT PELURUHAN GETARAN HASIL PELEDAKAN DI PROYEK TEROWONGAN NANJUNG MENGGUNAKAN RUMUS LANGEFORS-KIHLSTROM DAN USBM

• Main Author: Eldrian Hendra, Anthony
• Format: Final Project
• Language: Indonesia
• Subjects: Pertambangan dan operasi berkaitan
• Online Access: https://digilib.itb.ac.id/gdl/view/51648
• Institution: Institut Teknologi Bandung

Nanjung water tunnel is a part of flood anticipation at Citarum river upstream. Nanjung water tunne thatl is located at Citarum river upstream area at Jompong waterfall, was built to facilitate the flow of water at Citarum river upstream down to downstream, so it will decrease the flood at Bandung district. The tunnel is consist of 2 main tunnels that eachs 8 meter diameter and 230 meter length. The tunnel increases capacity of Citarum river flow from 570 cubic meter per second to 643 cubic meter per second and decreases flood area from 490 square km to 80 square km. In Nanjung water tunnel development, method used in tunnel development is conventional digging using heavy equipment on weak rock mass area and drilling-blasting on strong rock mass. In drilling-blasting process at Nanjung water tunnel project, there is a few thing to look out for, which is vibration level because the location of the project is near PT Gistex factory chimney and civilian houses. Base on SNI 7571 : 2020 about The standard of vibration level for Blasting of Open Mining Activities to Buildings, the value of safe vibration levels for buildings around the project site, namely class 2: buildings with foundations, masonry and mortar only, is 3 mm / second. The problem of the level of vibration from the blasting results in the Nanjung water tunnel can be overcome by making analyzes and predictions of the blasting design based on previous data. In analyzing and predicting the level of vibration decay, the peak particle velocity formulas for USBM and Langefors-Kihlstrom are used. The results of the analysis show that the decay of the vibration level in the Nanjung water tunnel project can be further illustrated by the USBM formula with a decay coefficient (n) of -0.15 and rock factor of 4.42 for confident level 90% on chimney scout point and decay coefficient of -0.78 and rock factor of 211.2 for confident level 90% on tunnel base level scout point.