chapter  8
55 Pages

Structural regularity

The t r a d i t i o n a l des ign p h i l o s o p h y of seismic-resistant structures is based u p o n the d i s s i p a t i o n of the ear thquake i n p u t energy b y means of plast ic excursions, l e a d i n g to s t r u c t u r a l damage w h i c h has to be c o n t r o l l e d i n order to p r e v e n t fa i lure . The a b i l i t y of a s t ructure to w i t h s t a n d severe earthquakes is s t r i c t ly related to its capacity to u n i f o r m l y d i s t r i b u t e the s t r u c t u r a l damage. I n the classical des ign a p p r o a c h the damage concentrat ions can lead to fa i lure modes w h i c h are characterized b y a r e d u c e d d i s s i p a t i o n capacity. Therefore, i t is u n i v e r s a l l y recognized that i t is necessary to a v o i d the u n c o n t r o l l e d concentrat ion of the ear thquake i n p u t energy; a n except ion is m a d e for cases i n w h i c h this energy is i n t e n t i o n a l l y d i rec ted i n t o specif ical ly designed diss ipat ive elements.