Piping Potential due to springs in dam (Case study : Titab Dam)

Abstract

The dam is one of the water infrastructures that can function as conservation, utilization, and control of the destructive power of water. Titab Dam is one of the dams in Indonesia that has multifunction as irrigation water, raw water and hydropower. This dam is a type of rock fill dam with an upright core which has a peak length of 210 m, a width of 12 m, and a height of 78 m from the deepest foundation. This dam was built with relatively complex geological conditions and landslides occurred on the spillway walls and springs were found in the landslides so it was necessary to analyze the potential for piping due to the presence of springs. This study examines the potential for piping due to the influence of springs near the dam. The study was conducted based on instrument observations during the inundation period from 2016 to 2019. The analysis was carried out by calculating the acceptance criteria (KP) for seepage and seepage index (Qi) to determine seepage behavior in the dam body and a safety factor analysis (FK) for piping hazards was carried out by comparing the hydraulic gradient based on piezometer instrumentation readings and the hydraulic gradient of the dam body core material. Based on the calculation of the seepage acceptance criteria and the seepage index, the seepage that occurs in the Titab Dam is not safe because it exceeds the requirements, the average seepage occurs is 6.350 > 0.56 liter/minute/m and Qi > 1. However, the analysis of the safety factor of piping hazard is still safe that is equal to 8,390 > 4.

Keywords

• bendungan urugan
• rembesan
• piping
• faktor keamanan (fk)