PSI - Issue 11

Gloria Terenzi et al. / Procedia Structural Integrity 11 (2018) 161–168

165

5

Terenzi G

, Costoli I, Sora

ce S, Spinelli P /

Structural Integr

ity Procedia 00 (

2018) 000–000

a )

b )

c )

onstituting profil

Fig. 5

. Steel columns o

n the ground and

the first storey;

section ( a ), later

al view ( b ) and c

es ( c ).

e modal ana tion periods g Y , and 38.9% ributions up t tions (equal t Time-history e performanc dards (Italian eded over th c Design Ear V R probability f 50 years by ory T1 (flat red to the city e results of th here the inter directions. As ediate Occup rmance level and MCE se ty performanc the other han nsions of 100 and 85.1 kN, iencies were etrofit hypot sed on the re ic performan ducing a diss

lysis showed of 0.466 s ( Y along X . Th o the thirteen o 88.7% alon verification a e evaluation Public Work e reference ti thquake (BD ). The V R per a coefficien surface), an of Florence e analysis car storey drifts n shown by th ancy level th limitation (d ismic levels e level by the d, the axial ×8 mm×mm) are exceede found also in hesis sults of the a ce of the stee ipative bracin

two first ho ) and 0.46 s e above-men th mode, by g X , and 85.3 nd performan enquiry was s 2008), that me period V R E, with 10% iod is fixed a t of use C u e d B-type soil are as follows ried out in cu ormalized to ese diagrams reshold ( d i , IO i,OP =0,33%) o the drifts are American St force instabili , as well as th d by a factor the cantilever

rizontal tran ( X ), respectiv tioned structu which summ % along Y ). ce assessmen carried out f is, Frequent ); Serviceabi / V R probabili t 75 years, w qual to 1.5, , the resultin : 0.065 g (FD rrent state are the storey he , all values ca =0,5%). At t n the second neatly below andard ASCE ty limits com e diagonal on equal to ab beams suppo

slational mod ely, and effec ral irregularit ed modal ma t analysis or the four r Design Earth lity Design E ty); and Max hich is obtain imposed to sc g peak groun E), 0.078 g (S synthesized, ights are plott lculated for he same time storey, wher the 2% thresh -41. puted for the es (L profile out 1.5, at th rting the clad

es along X tive modal m y in height gi sses greater

and Y , with asses (EMM ves rise to no than 85% are

nearly coinc s) equal to 4 t negligible m activated in

iding 6.5% odal both

Th vibra alon cont direc

3.2.

Th Stan exce Basi 5%/ V N o categ refer Th 6, w 6 b ) Imm perfo BDE Safe On dime kN defic 4. R Ba seism intro

eference seis quake (FDE, arthquake (S imum Consi ed by multipl hool buildin d acceleratio DE), 0.181 g in terms of d ed for X ( d ix the SDE-scale , they only s e the normali old suggeste vertical profi s 60×5 mm×m e BDE, and ding panels.

mic levels fi with 81% pr DE, with 50% dered Earthq ying the nom gs. By referri ns for the fo (BDE), and 0 isplacement r – Figure 6 a ) a d seismic act lightly excee zed drift reac d for steel str les of column m), respectiv about 2, at t

xed in the It obability of b / V R probabi uake (MCE, inal structura ng to topogra ur seismic l .227 g (MCE esponse, in F nd Y ( d iy – F ion are below d the Operat hes 0,35%. A uctures at the s (L profiles ely equal to 2 he MCE. Si

alian eing lity); with l life phic evels ). igure igure the ional t the Life with 98.2 milar

ssessment an l members bo g system in b

alysis in curr th locally, by oth directions

ent condition strengthenin in plan, was

s, a retrofit s g the steel can proposed. Th

olution aimed tilever beam e intervention

at improvin s, and globall on the canti

g the y, by lever