Evaluation of the Open Diversion Channel Capacity on Margatiga Dam Construction Project using 6D BIM Analysis

Abstract

The Margatiga Dam is designed to combine a gravity concrete dam and rockfill with an upright core. In the Margatiga Dam Project, river diversion is carried out in 2 stages. Stage 1 through a trapezoidal open channel with discharge plan of Q10 years approximately 789.10 m3/second and stage 2 with the diversion discharge of Q25 years approximately 976.90 m3/second. During construction, the stage 1 diversion channel is built with a capacity that exceeds the planned design due to the very high water level fluctuations. Moreover, an evaluation is needed regarding the annual plan discharge that passes through stage 1. The Evaluation is based on data from the desk study and 6D BIM analysis. Based on the analysis, the water level is at elevation +19.50. The discharge through the diversion channel on this stage is 884.69 m3/second; this discharge exceeds the planned discharge design for diversion channel stage 1 with an annual Q10 discharge of approximately 789.10 m3/second.