178 M.Majowiecki STEP LOAD PROELE-A-A Rce Fig.4.Sliding and wind snow accumulations step loads magnitude of the leopardized accumulations in the roof are of 4-15 kN!;local overdi- mensioning was necessary in order to avoid progressive collapse of the structural system. 2.2 Wind Loading-Experimental Analysis on Scale Models:Rigid Structures-Quasi Static Behaviour The Cp factors:the Olympiakos Stadium in Athens Tests have been performed in two distinct phases,the first phase has been devoted to the characterization of the appropriate wind profile in the BLWT,the second one has been dedicated to the identification of the pressure coefficients on the roofing of the new stadium.Because of the great number of pressure taps on the roofing(252), the second phase consisted of three distinct measurement sets. The stadium is located near to the sea,as a consequence a "sea wind profile" with the parameters listed below and taken from literature and laboratory expertise, seems to be a good approximation of the wind profile in the area(Fig.5): profile exponent a =0.15/0.18 (level ground,with few obstacles,sea), roughness length zo =5/15 cm (cultivated fields), integral length scale Lw=50/100m. In the following paragraph the characteristics of the wind profile actually ob- tained in the BLWT are examined,and the consistency of the choice in the chosen geometric scale (1:250).178 M. Majowiecki Fig. 4. Sliding and wind snow accumulations step loads magnitude of the leopardized accumulations in the roof are of 4-15 kN!; local overdi￾mensioning was necessary in order to avoid progressive collapse of the structural system. 2.2 Wind Loading-Experimental Analysis on Scale Models: Rigid Structures-Quasi Static Behaviour The Cp factors: the Olympiakos Stadium in Athens Tests have been performed in two distinct phases, the first phase has been devoted to the characterization of the appropriate wind profile in the BLWT, the second one has been dedicated to the identification of the pressure coefficients on the roofing of the new stadium. Because of the great number of pressure taps on the roofing (252), the second phase consisted of three distinct measurement sets. The stadium is located near to the sea, as a consequence a “sea wind profile” with the parameters listed below and taken from literature and laboratory expertise, seems to be a good approximation of the wind profile in the area (Fig. 5): profile exponent α = 0.15/0.18 (level ground, with few obstacles, sea), roughness length z0 = 5/15 cm (cultivated fields), integral length scale LU = 50/100 m. In the following paragraph the characteristics of the wind profile actually ob￾tained in the BLWT are examined, and the consistency of the choice in the chosen geometric scale (1:250)