Applications and analiyses of slurry trench in Buyukkumla dam construction

In this day and age, concrete face rockfill dams (CFRDs) are one of the most preferred dam type in dam constructions. There are several reasons in selecting CFRD type such as distant or insufficient impermeable clay material to construction site, practicality in construction phase, usually low construction cost in narrow valleys, ideal type in earthquake zones and also less problems for excessive settlement and water leakage due to compaction of rock filling. In this type of dam, there is no need for much of ground bearing capacity. Foundation excavation of Büyükkumla Dam was performed under sea water level. A slurry trench application in Büyükkumla Dam became necessary in order to remove the effects of seawater and groundwater while carrying out its excavations below sea water level in a dry condition. For this reason, seawater access to the dam reservoir is blocked and possible seepages under dam body is got under control. Slurry trench is applied both under upstream and downstream cofferdam axis. The aim of slurry trench method blocks seepage or increases the length of seepage line, it has no contribution to dam stability. In this study, slurry trench field application is priorly explained and then numerically modeled using geotechnical software Seep/w and Midas Gts Nx. Then, numerical computation results are compared with in-situ readings. It is seen that model results are considerably close to the in-situ results and under allowable safety factors as well.