6926475946

Key Word*: Buildings, Seismic datign

Kay Word*: Buildings, Torsional rasponea, Salemie e*cKatk>n

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Struć. Dynam., 12. (2). pp 149-167 (Mar/Apr 1984) 24 figs, 6 refs

In recognition of tht life-threetening dangers posad by many thouands of buildings complatad pctor to tha requirament for provision of any ipecrfk: aarthqueke resistence. In 1981 tha city of Lot Angeles adopted a taiimic aafety ordinanca raquiring tha upgrading of thaee buildings to pradatarminad engineering standard*. Various methodi of modifying such structuret, which ara charactaristically of unrainforcad multi-story maeonry baaring Mail configuration with interior wood framing, ara summarizad in thi* papar. In addhion to prasanting typical structural dęta ii*. some of tha socio-economie and finencJel aipecti of tha aarthquaka hazard mitigation program ara ditcusead.

84-1589

Dynamie Reąranie of Buildings to Ground Rota-tionaJ Motion

A.M. Awad and J.L. Humar

Faculty of Engrg., Univ. of Alexandria, Alexandria. Egypt, Can. J. Civil Engrg., JJ_(1), pp 48-56 (Mar 1984) 7 figs, 13 refs

Torsional motion in a buiiding subjactad to aarthquaka for ca is often attributad to an accantriclty between tha center* of mass and rasietanca of tha buMding. However, a mora diract causa of torsional responsa is tha presence of a rotational componant in tha aarthquake motion. Tha affact of such a rotational motion on tha re«>onsa of both a symmatric and an unsymmatric *lngle story buiiding model is studied. It is shown that tha rotational componant of axcltation may hava a vory signrfkant affact on tha responsa, and that thts affact may at timas ba mora pronouncad than tha affact of torsion reeuhing from transiationol motton oomblned with plan accantricity.

84-1590

lite Optimom Design of a Baee iaolatioa System aritók Frktional Deamti

M.C. Constantinou and I.G. Tadjbakhsh Rensselaer Polytechnic Inst., Troy, NY, Earthquake Engrg. Struć. Dynam.. 12 (2). pp 203*214 (Mar/Apr 1984) 5 figs. 6 tables, 15 refs

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Kay Word*: Buiiding*, Muitistory buildings. Seismic design, Basa isoiation

A linear muitistory structure with a seismic basa isoiation system consisting of rubber baaring* and frictional element* is considered. The nonlinaar equations of motion ara derived for tha first moda vibration and the Stocha Stic responsa to a white noise ground acceleration is determined. Basad on this responsa, suitable objective functions ara dsfined and the optimum design of the isoiation system is performed. It is shown that a smali amourtt of friction ineraases the effective-ness of the system comparad with tha same system but wrthout frictionsl element*.

TOWERS

84-1591

Dynamics of a FreeaUnduę Steel Ugktiag Tower

K.C.S. Kwok, G.J. Hancock, P A. Bailey, and P.T. Haylen

School of Civil and Mining Engrg., Sydney Univ., Australia, Rept. No R-450. 30 pp (June 1983)

PB84 137934

Kay Word* Towera. Steel, Natursl frequencie«. Moda

Raeults of fuli scala maesuremems of tha dynamie charac-tariatics of a mmi Ighuoę towar ara preser*ad Tha first three natural fraquencies of vlbratton wers found to ba 0.60 Hz, 2.40 Hz and 4M4 Hi respectfcWy Tha oorraapond-Ing moda dtapas wara alao determined Theae raeults are oomparad with thoaa obtainad from a piana riętd trama dynamie analysis Computer program ar^ found *ob*m good

FOUNDATION8

84-1592

Eartkquake Re^oaat of Uptift on Wiakler Fonnfatma

Chik-Sing Yim and A K. Chopra Univ. of California. Berkeley, CA. Earthquake Engrg. Struć. Dynam., Ji(2). pp 263-281 (Mar/Apr 1984) 12 figs. 12 refs

Kay Wordt: Winkler foundattone, Foundation*. Salemie

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