Aspects Regarding the Use of Topographic Measurements for Monitoring Drăgan Valley Dam

Abstract

Dragan Valley Dam is located in Cluj County near Ciucea and is built on plots and blades in double arc. With a height of 120 m and a canopy length of 424 m, the dam is considered the fifth largest in the country. Determining the horizontal displacements of the tracking landmarks embedded in the downstream face, respectively determining the vertical displacements of the landmarks located on the crest using topographic measurements. The displacements are obtained by the difference between the coordinates, heights determined in the current set of measurements and initial set respectively. To determine the horizontal displacement, a micro-triangulation network was created in a local coordinate system, with X axis direction oriented downstream-upstream of the dam, and the Y axis to the direction of growth on left bank. Support Network is formed of eleven pillars found on the bedrock and sixty-nine tracking markers mounted on the downstream of the dam. Altimetric network is formed of thirty-three leveling landmarks located on the crest and two fixed landmarks situated at the edges of the dam. Planimetric measurements were made with a Leica TS30 total station, and the altimetric measurements with a Leica DNA 03, which provides an accuracy of 0.3 mm / 1km double leveling. After processing the azimuthal measurements with indirect measurements method and using statistical assumptions, pilasters I, II and VII were considered as fixed stations. Maximum shifts in downstream were recorded at landmark R7 (-42.3 mm) and maximum was recorded at the landmark R33. Horizontal and vertical displacement values of planimetric and altimetric landmarks, obtained after carrying out topographical observations and their processing, falls within allowable tolerances, which shows stability in the functionality of the dam.