I don't understand which is the set of action for design a section: for example, the max values of bending moment and shear are not in the same moment for a section, but they has interaction in the design (for example see Eurocode 3). Taking all max values seem to be too onerous. And so?
thanks very much but what if we want to use the mean spectra of 7 main earthquakes which include 3 directional records each and then compare the result with a default spectra, then modify it and after that use it in SAP or ETABS?
The P acific E arthquake E ngineering R esearch (PEER), headquartered at the University of California at Berkeley , makes available online over 10,000 strong ground motion records from 173 different earthquakes
By right-clicking on the appropriate record (NGA0006 in our case), a new page is shown with all the relevant pieces of information about this seismic event
If we scroll down, the links to the three components of the accelerogram (180°, 270° and vertical) appear
9.
Download the time history of the ground acceleration
By right-clicking on one of these links (e.g. the first horizontal component, denote with IMPVALL/I-ELC180), a new textual page is opened with the corresponding time history of the ground acceleration
The analysis case in presence of accelerogram is a TIME HISTORY , which can be selected from a drop-down list after clicking on the ADD NEW CASE... button
The load type is an ACCEL eration of the ground (first drop-down list)
For a planar model, the ground shaking is generally assumed to happen in the X direction, i.e. Load name U1 (seconddrop-down list)
The records from the PEER website are given in units of g, so the scale factor would be 9.81 m/s 2 or 981 cm/s 2 , depending on the units selected in the model of SAP2000
The number of time steps should be given by the duration of the accelerogram divided by the sampling time: