Determining the appropriate sealing conditions through a permeability and groutability evaluation: a case study of the Sivaki Dam, Iran

Abstract

The Sivaki Dam is an earth dam that is located near Yasuj city, 5.3 km NW of Sepidar village. During excavations at the dam construction site, the high potential of water seepage from the foundation and its abutments has been proven. Some cavities and dissolution have been observed on both sides of the dam, suggesting the possibility of karstification at greater depths. Most of the rocks cropping out in the study area comprise Asmari Limestone. These rock masses, despite their medium–high strength, have provided unfavourable conditions in terms of permeability and weathering. In this study, the foundation and both abutments of the dam were evaluated and analysed to determine the permeability and groutability characteristics. To achieve this goal, the engineering characteristics of the rock mass of the construction site were examined by performing rock mass rating (RMR) and geological strength index (GSI) classifications. The Lugeon test, secondary permeability index (SPI), rock quality designation (RQD) and monitoring hydraulic flows were used for this purpose. According to the results of this study, for abutments of the dam and in the case of alluvial substrates, a grout curtain and cutoff wall, respectively, are the best and most compatible methods available.