Evaluation of stability in rock-fill dams by numerical analysis methods: a case study (Gümüşhane-Midi Dam, Türkiye)

Abstract

Serious stability issues could arise both during and after construction if the dams’ hull designs are not realistically accurate. Engineering studies are therefore crucial for identifying the body’s instability properties in designing the dam body. In this study, horizontal and vertical displacement and stress-deformation analyses were carried out on the body of the Midi Waste Dam located in Karamustafa Village of Gümüşhane Province. In these analyses, the elasticity modulus and Poisson’s ratio of the soil were determined using the seismic method, which is one of the commonly used geophysical methods. The cohesion and internal friction angle of the rock fill were determined by taking into account Leps’ charts. The state of the dam body under the influence of the siltation load and seismic load at the end of operation was shown by applying the finite element method. It was found that there was no instability issue with the researched dam because the safety numbers obtained from the stability study of the dam body were greater than the 1.2 safety number accepted for the stability of the dams (SRF: 2.03, SRF: 1.37). The maximum vertical displacement of the dam body at the foundation base was found as 3.78 cm, the horizontal displacement as 5.80 cm, and the total displacement amount as 6.75 cm when the dam body was examined in terms of displacements. In terms of the statics of the dam body, the vertical, horizontal, and total displacements estimated with the numerical analysis methods did not present a problem, and it was demonstrated that this scenario was also supported by the stability of the body in the applied analyses.