| Abstrak/Abstract |
Budong-Budong Dam uses a tunnel to divert river flow while constructing the dam's body. The risk of landslides on the tunnel outlet portal slopes can occur due to geometry changes caused by excavation or earthquakes that can disrupt dam construction. The stability analysis of the tunnel outlet portal slope has not been conducted. The purpose of this research is to assess the stability of the slopes at the tunnel's portal outlet. The data were collected by geological mapping, rock mass quality assessment, laboratory testing, and secondary data. Bishop Simplified and Morgenstern-Price approach in static and pseudo-static are used in the slope stability study. Drilling log data showed that the tunnel's portal outlet slope consists of Residual Soil, Tuffaceous Sandstone insert of Tuffaceous Siltstone, and Tuffaceous Breccia. The slope safety factor has a value above 1.5 when analyzed in static conditions, where the Bishop Simplified approach produces a safety factor of 2.202, and the Morgenstern-Price produces 2.272. Meanwhile, in pseudo-static conditions, Bishop Simplified has a safety factor of 1.929, and Morgenstern-Price has 1.938. |
