Hoja3

DISEO DE COLUMNACOLUMNA 1 EXT.Datos:Pu=7.5Tnd1=5.65As1d2=20Mu=1.4Tn-mYo=20f'c=280Kg/cm2As2d3=35.85Fy=4200Kg/cm2h=40 cmb =65cmAs3h =40cm(%) =2=0.02b=65 cmestribo =3/8=0.95cmN acero long=10acero long=5/8=1.59cmArea (cm2) =1.98Recub =4cms =0.0021Refuerzo maximo y minimo en columnas (segn codigo ACI):Ag =b x h(area de seccion bruta)Ag =2600cm2Ref. max =0.08Ag=208.00cm2Ref. min =0.01Ag=26.00cm2

Ast =10xArea (cm2) =19.79entonces:Ast < Ref. max.OK!As1 =3.96d1 =5.65cmAs2 =3.96d2 =20cmAs3 =3.96d3 =35.85cm

posicion del centroide plastico a la mitadde la seccion:Yo =20cm

Cb =6000*d / (6000 + Fy)Cb =21.09cmab =0.85*Cbab =17.93cmFsi =6*((C - di) / C)Fs1 =4.39Cs1 =17.39TnFs2 =0.31Cs2 =1.23TnFs3 =4.20Ts3 =16.63TnCc =0.85*f'c*b*aCc =277.30Tnentonces:Pnb =Cc + Cs1 + Cs2 - Ts3Pnb =279.29TnMnb =Cc*(Yo-a/2) + Cs1*(Yo-d1) + Cs2*(Yo-d2) + Ts3(d3-Yo)Mnb =35.74Tn-mLuego:eb =Mnb / Pnbeb =0.13m

Asumiendo:C =19.00cma =16.15cmCc =0.85*f'c*b*aCc =249.8405TnFs1 =5.86Cs1 =23.21TnFs2 =-0.32Cs2 =-1.25TnFs3 =-5.32Ts3 =-21.06Tn

Pn =250.74TnPn =175.52TnMn =30.88Tn-mMn =21.61Tn-men =0.12men =0.123m

verificando:Pn =175.52>Pu=7.5.OK!Mn =21.61>Mu=1.4.OK!en =0.12=eb =0.13OK!por lo tanto usar:6 1/2"OK!

Refuerzo Transversal:S 16 p =25.44cm( 1 )S 48 estr.=45.60cm( 2 )de ( 1 ) y ( 2 ) se elige el menor:Usar estribos: 3/8" @ .20 cm..OK!