ISO 28842-2013 pdf free download

ISO 28842-2013 pdf free download.Guidelines for the simplified design of reinforced concrete bridges
Lignes directrices pour Ia conception simplifiée des ponts en béton armé.
8.7 Earthquake inertial forces
8.7.1 General
Inertial forces due to earthquakes clepenct on tne mass oi me structure anO on me structural response to ground acceleration which, in turn is a function of the seismic hazard and of the soil characteristics at the site of the bridge.
The requirements of the National corresponding Standard should be met when calculating the mass of bridge building materials. When no National Standard is available, the requirements of ISO 9194 may be used. Table 6 of these guidelines may also be used to determine bridge masses.
For bridges which may be designed under these guidelines, an equivalent lateral force applied directly to the substructure and superstructure elements may be employed to represent the dynamic response of the structure to the ground acceleration.
8.7.2 Seismic hazard
A level of seismic hazard should be defined for the bridge in terms of the intensity of the effective peak ground
horizontal acceleration in rock at the stwcturesite. The peak rock acceleration is calculated as the median
spectral acceleration for one degree of freedom systems. with short periods of structural vibration. i.e., periods
not exceeding 0.15 seconds, denoted as Aa, and usually expressed as a traction of the acceleration of gravity,
g (Acceleration of gravity may taken as 9.81 m/)
For the purpose of the scope of these guidelines, the values for A, must be taken from the National corresponding Standard having jurisdiction over the site of the considered existing structure. When the national code defines the maximum seismic ground motion for each considered site based on spectral response accelerations at 5 % of critical damping, S5. A, may be estimated as the value of Ss for a period of 0.15 seconds, divided by 375 (A, = Ss/375). When the national code defines the maximum seismic ground motion for each considered site based on a seismic zone factor Z, the value of A., should be taken equal to 2. When no national code exists for the site of the bridge being considered, A, may be estimated from the seismic hazard maps shown in Figure 8.
8.7.3 No seismic hazard zones:
A zone at the world where the value of the peak rock acceleration, A,, expressed as a percentage of the acceleration of gravity, is estimated as less or equal to [0.05), may be deemed as a no seismic hazard zone.ISO 28842-2013 pdf free download.