Lessons learnt from building damages in the Wenchuan earthquake——seismic concept design of buildings

Severe damages and collapses of buildings were caused by the Wenchuan earthquake.Based on the damage data collected in regions suffered moderate to severe intensities,lessons learnt from the event dealing with the 3-earthquake performance level and seismic concept design issued by the national Code for Seismic Design of Buildings(GB 50011—2001) are summarized.A comparison between the actual damage and the expected damage on the given level for different structures is carried out.A discussion is made on seismic design of the multi-fortification,strong column-weak beam,link beam of shear walls,integration and ductility of masonry structures,exit ways and staircase of buildings and non-structural elements,etc.Some sugestions for improving the seismic design of structures are also given in this paper.The study on the damages shows that the three performance objectives named failure for minor earthquake,repairable for moderate earthquake and no collapse for major earthquake can be achieved only if the seismic design of buildings strickly follows the code and the quality of construction is assured.