SIMULATION OF BENCH DRAINAGE CAPACITY AT A SINGLE BENCH OF EMBANKMENT IN MINES

• Main Author: Handoyo, Christopher
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76810
• Institution: Institut Teknologi Bandung

Bench drainage is a drainage facility in embankments designed to handle runoff at each bench level. In cases where rainfall runoff exceeds the capacity of the bench drainage, water will overflow, causing instability in the embankment. Therefore, it is necessary to simulate the capacity of bench drainage at each individual embankment bench to ensure its ability to manage rainfall runoff. Rainfall runoff is analyzed based on the Synthetic Unit Hydrograph SCS with input data of one-hour rainfall events with return periods ranging from 2 to 40 years. The catchment area is determined based on the bench's catchment area, which is determined by variations in slope angle and bench width. Slope angle variations range from 20% to 50%, which are commonly used values for rock cover embankments. Bench width variations are made based on the consideration of the operational vehicle capacity used. The resulting bench drainage variations consist of triangular channels with a width-to-depth ratio of 1:1, utilizing half the bench width and the full bench width. Capacity to accommodate discharge is determined by comparing the peak rainfall runoff discharge with the capacity of the bench drainage discharge. Meanwhile, volume capacity is determined by comparing the rainfall runoff volume with the bench drainage volume capacity. The research results show that only bench drainage with full bench width dimensions at the two-way bench can handle the peak rainfall runoff discharge. The same applies to volume capacity, where only bench drainage with full bench width dimensions at the two-way bench level can handle rainfall runoff volume. This is because the required filling time exceeds the duration of the peak rainfall runoff.