OPTIMIZATION OF THE BOTTOM CONTROLLER PLACEMENT TO COUNTERMEASURE THE DEGRADATION OF CIPAMINGKIS RIVER IN BOGOR REGENCY WEST JAVA PROVINCE

• Main Author: Ramdhany, Deny
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/54430
• Institution: Institut Teknologi Bandung

The problem of degradation of the Cipamingkis River between old Cipamingkis Weir to the Cibarusah Bridge has not been resolved until now. There are 10 bottom controllers or river bed control structures (BK) that have been built downstream of the weir to the Cibarusah Bridge which were damaged several times until they finally suffered destruction. The condition of the Cipamingkis River is currently experiencing degradation as a result of uncontrolled mining of C excavation since 1983. This degradation has damaged the Cipamingkis Weir, which functions to irrigate ± 7500 ha of irrigated land, so that in 1997 it had to be repaired by adding triple stilling basin and BK downstream of the weir. The purpose of this study was to determine the pattern of degradation from the old Cipamingkis Weir to the Cibarusah Bridge, so that the number, location and height of the BK can be proposed in order to prevent structural failure. Six simulation scenarios have been carried out to determine the pattern of morphological changes without BK, determine the cause of BK collapse, and control efforts to prevent weir, bridges and BK from collapsing again. The simulation was carried out using MIKE 11 application with input model discharge data, river topography, river bed gradation and roughness coefficient. Without consider the excavation mining and geological conditions. The simulation results without BK in scenarios 1 and 3, show that the potential for degradation occurs in the weirs and bridges, with the highest degradation in the upstream of the Jonggol Cariu Bridge at 2.6 m. Scenarios 2 and 4 are carried out to determine the morphological changes at the time 10 old BK were built without considering the destruction of BK. The simulation results show that the downstream of BK 9, BK 10 and BK 13 have the potential to occur degradation, while BK 5 and BK 6 have the potential to cause increased degradation upstream of the Jonggol Cariu Bridge. Meanwhile, scenario 5 provides an illustration of how 10 old BK have destruction due to the potential degradation that occurs at downstream of the BK. From the results of scenarios 1 to 5, it can be concluded that the installation of BK must pay attention to the conditions of morphological changes, so that each BK must built synergize with each other and maintain the stability of the main structure and the BK itself. In order to prevent damages to the weir structures, bridges and BK. 11 BK are proposed to be built and divided into two phases. In the first phase, 8 BK were built, 4 BK were built at the downstream of the old Cipamingkis Weir, 2 BK were built at the downstream of the Jonggol Cariu Bridge and 2 BK were built at the downstream of the Cibarusah Bridge. Meanwhile, the second phase is to add 3 BK to prevent the BK that has been built damage. This research is expected to be useful for stakeholders or river managers and also as a starting point for further research on the Cipamingkis River.