Seite - 1024 - in Book of Full Papers - Symposium Hydro Engineering

3. ANALYSIS AND INTERPRETATION OF THE STRUCTURAL BEHAVIOUR 3.1. STRUCTURAL MODEL The dam behaviour was analyzed and interpreted on the basis of the monitoring results and of a continuous structural model (because no significant movement variations were observed in the contraction joints during the first filling). The structure of the dam was approximated by a set of supposedly continuous and homogeneous blocks, considering 30 monthly construction stages, with a rheologic behaviour of the concrete characterized by expression (1) and by Poisson ratio νc=0.2. The rock mass foundation was divided in 7 zones of different deformability, as a function of the results obtained from the geomechanical characterization [2] and “in situ” seismic tomography tests [5]. The Poisson ratio was assumed with a value of νf=0.2 for all the zones. No time effects on the foundation behaviour have been considered. The finite element mesh (Fig. 3) has a total of 14854 nodal points for 2795 isoparametric cubic 20 nodes finite elements (1067 elements of the dam’s body and 1728 elements of the rock mass foundation). The dam’s body has 3 elements across the thickness. The spans and the shapes of the surface spillway were explicitly represented in the finite element mesh. Fig. 3 Dam-foundation finite element mesh considered in structural analysis Dam’s concrete (month of casting): Rock mass foundation (Young modulus): Ef1 = 20 GPa Ef2 = 30 GPa Ef3 = 25 GPa Ef4 = 20 GPa Ef5 = 15 GPa Ef6 = 10 GPa Ef7 = 40 GPa 01-2013 02-2013 03-2013 12-2012 08-2012 01-2012 02-2012 03-2012 04-2012 05-2012 06-2012 07-2012 05-2011 06-2011 07-2011 08-2011 09-2011 10-2011 11-2011 12-2011 09-2012 10-2012 11-2012 04-2013 05-2013 06-2013 07-2013 08-2013 09-2013 10-2013 1024