EXAMPLE 6. BUILDING VALUATION & REDESIGN STUDY

EXAMPLE 6: "STUDY FOR THE VALUATION AND REDESIGN OF A BUILDING ACCORDING TO THE CANC. 87 where Se(T) is the elastic spectral pseudo-spectral acceleration (from the spectrum of EC 8-1) corresponding to the equivalent eigenperiod of the structure Te (calculated from the inflexion point of the force-displacement diagram of the , as defined in § 5.7.3.4), and C0, C1, C2 and C3 are correction factors defined as follows: ▪ C0: Coefficient relating the spectral displacement of the equivalent elastic carrier with stiffness Ke (Sd=[Te2/4π2] ⋅ Φe) to the actual displacement δt of the peak of the elasto-plastically responsive carrier. (§5.7.3.4). Its values may be taken equal to 1.0, 1.2, 1.3, 1.4, 1.5, for numbers of floors 1, 2, 3, 5, and ≥10, respectively. ▪ The ratio C1=δinel/δel of the maximum inelastic displacement of a building to the corresponding elastic displacement may be obtained from the relationships: C1=1.0 for T≥ Tc , and C1=[1.0+(R-1)Tc/ T]/R for T < Tc , where Tc is the value at which the bad branch of the response spectrum begins (see EC 8-1) and R=Vel/Vy is the ratio of the elastic demand to the yield strength of the carrier. This ratio can be estimated from the relation R= ((Φe/g)/(Vv/W)).Cm ,(Σ5.7) in which the leakage resistance Vy is calculated by appropriate bilinearisation of the force (base shear) - displacement (top) diagram of the building, as defined in § 5.7.3.4. Simplifying (and on the safety side), the ratio Vy/W in relation (S5.7) can be taken as 0.15 for buildings with a mixed system, and 0.10 for buildings with a purely framed system. ▪ C2: Coefficient taking into account the influence of the shape of the hysteresis loop at maximum movement. Its values can taken from Table C5.1. For T values between 0.1s and Tc, linear interpolation shall be used. ❖ Finally, in the section "Extent of damage for the calculation of γSd" you select the extent of damage in your building in order to take into account the appropriate safety factor of the γSd actions