Failure risk investigation of any structure in a seismic zone can be done by the seismic probabilistic risk assessment (SPRA), which became a very attractive area of research in terms of safety measurement. This paper introduces such kind of concept to identify which magnitude in a specific seismic zone will contribute more vulnerable failure point in a structure. Here, for implement this idea a case study on a concrete gravity dam has been carried out. In order to make a correlation between the magnitude and failure risk contribution based on different damage stage, a combination of seismic hazard analysis and the probability of structural collapse is adopted. Therefore, the deaggregation of the mean annual frequency of failure risk by magnitude is used in this study to quantify four different limit stages of failure identification criteria. Consequently, from analyzing the result, in case of concrete gravity dam, this deaggregation approach shows the tensile crack in the base looks more vulnerable damage stage for the specific seismic zone.

Network design of the Reservoir Failure Forecasting System are proposed to using LPWA network in order to actively respond to the power problem, breaking communication wire and cost reduction of management system.

Web-based DB design standards of the Reservoir Failure Forecasting System are proposed in order to actively respond to the user’s work changes, various sensors, and business logic, and increase the system usability by reducing logic changes and client maintenance through minimal interface changes.

Web-based DB design standards of the Reservoir Failure Forecasting System are proposed in order to actively respond to the user’s work changes, various sensors, and business logic, and increase the system usability by reducing logic changes and client maintenance through minimal interface changes.

A 3D seepage flow numerical simulation model was developed for seepage analysis of a landslide dam. A 3D seepage flow numerical simulation model coupled with a 2D surface flow and erosion/deposition model was developed for seepage analysis of a slope due to a rainfall event. The conventional water-phase (one-phase) seepage flow model assumes only water phase flow in seepage analysis, which is inadequate for unsaturated soil domains. Hence, a water-air two-phase seepage flow model that considers both water and air phase in the seepage flow process is also used for seepage analysis. Pore water pressure and moisture content data obtained by the seepage flow model were then used to analyze the stability of the slope. Janbu’s simplified method as well as the extended Spencer method was used for the stability analysis. Numerical simulation results and experimental measurements are satisfactorily in agreement.

This study aims at the analyze of unsteady downstream flow due to dam failure along dam failure scenario and applied to Yeoncheon Dam which was collapsed August 1st 1999, using HEC-RAS simulation model. The boundary conditions of this unsteady flow simulation are that dam failure arrival time could be at 02:45 a.m. August 1st 1999 and failure duration time could be also 30 minutes. Downstream 19.5 km from dam site was simulated for unsteady flow analysis in terms of dam failure and non-failure cases. For the parameter calibration, observed data of Jeonkok station were used and roughness coefficient was applied to simulation model. The result of the peak discharge difference was 2,696 to 1,745 m³/sec along the downstream between dam failure and non-failure and also peak elevation of water level showed meanly 0.6m difference. Those results of these studies show that dam failure scenarios for the unknown failure time and duration were rational because most results were coincident with observed records. And also those results and procedure could suggest how and when dam failure occurs and downstream unsteady flow analyzes.

This study aims at the estimation of dam failure time and dam failure scenario analysis of and applied to Yeoncheon Dam which was collapsed August 1st 1999, using HEC-HMS, DAMBRK-FLDWAV simulation model. As the result of the rainfall-runoff simulation, the lancet flood amount of the Yeoncheon Dam site was 10,324 m3/sec and the total outflow was 1,263.90 million m3. For the dam failure time estimation, 13 scenarios were assumed including dam failure duration time and starting time, which reviewed to the runoff results. The simulation time was established with 30 minutes intervals between one o'clock to 4 o'clock in the morning on August 1, 1999 for the setup standard for each case of the dam failure time estimation, considering the arrival time of the flood, when the actually measured water level was sharply raising at Jeongok station area of the Yeoncheon Dam downstream, As results, dam failure arrival time could be estimated at 02:45 a.m., August 1st 1999 and duration time could be also 30 minutes. Those results and procedure could suggest how and when dam failure occurs and analyzes.