Journal of Civil Engineering
Vol. 38 No. 3 (2023)

Evaluation of Discharge Calculation in Open Pit Mining

Ivan Kurniawan (Unknown)
Satria Damarnegara (Unknown)
Nastasia Festy Margini (Unknown)



Article Info

Publish Date
23 Jul 2025

Abstract

This study presents the discharge calculation of open pit mining drainage system in open pit mine at PT Maruwai Coal, in Central Kalimantan. Several calculation methods are compared, including FJ Mock, HEC-HMS, and 2D HEC-RAS simulation. The open pit mine drainage system consists of sump storage with volume of 12.574 m3 and discharged using 0,22 m3/s pump. The loss method for HEC-HMS and HEC-RAS is modelled using Curve Number (CN) approach. CN value choice need to consider steep slope condition at the site. Storage elevation and pump operation at 10 rainfall event is observed and used as model validation. The calculation shows each method is capable to model the event reasonably well. The average run-off coefficient varies from 0.72 for FJ Mock and 0.63 for HEC HMS. However, FJ Mock method gives daily average value and may underestimate the run-off discharge. Indeed, HEC-HMS and HEC-RAS model is more suitable for flood modelling because of unsteady nature of the flow.

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Journal Info

Abbrev

jce

Publisher

Subject

Civil Engineering, Building, Construction & Architecture Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Transportation

Description

Journal of Civil Engineering (eISSN 2579-9029/pISSN 2086-1206) is a new journal that preceded by the previous Civil Engineering Department ITS Journal which was well known as Jurnal Teknologi dan Rekayasa Sipil (TORSI). TORSI journal was established in March 1981. In 2009, TORSI journal name was ...