Static And Seismic Stability Analysis of Small Hydraulic Structure Under Seepage Load: A Case Study of Rawanduz Dam

Abstract

The analysis of the reservoir-dam-foundation coupled system is much more complicated than that of the structure alone because of the difference between the characteristics of the foundation and concrete dam. The small hydraulic structure may be built in seismically active regions, where ground movement would impose earth pressures. The safety of these structures should be investigated quite critically by logical and precise methods. Rawanduz dam subjected to EL-Centro earthquake-S00E component excitation was chosen as a typical case of study. The static and dynamic stability of the Rawanduz dam had been analyzed and evaluated. A 2-D Finite Element model employed using ANSYS software to simulated dam response. The water was modeled as an additive mass according to the theory of Westergaard on the back of the dam while leaving the rest of the reservoir inactive. The dam body is presumed homogeneous, elastic, and isotropic properties for mass material. The soil was assumed to be flexible and analyzed as a nonlinear material. When assessing the stability of the structure under the influence of the seepage loads, the structure was founded safe because the exit gradient value was equal to (0.25), which was less than the critical value of the exit gradient (1/6). Results showed that the principal stresses at the heel and toe of the dam were founded important to study the stability. The static and dynamic analysis findings indicate that the stress values are very low, hence satisfy the normal criteria for protection factors relating to the tensile and compressive strength of the concrete.