BI TP: DUL-5 - TI TRNG CN BNG

- Thng s u vo: + Cc lp hon thin sn: p1=1.2 kN/m2 + Hot ti gi nh ton sn: p2=2.4 kN/m2 + Khi lng ring Btng: =25kN/m3

- Tnh ton chiu dy sn: = = = 0.166 Chn hs= 170 mm - Trng lng sn: 0.17x1.1x25=4.675 kN/m2 - Tng ti tc dng ln sn: Q=1.2 + 2.4 + 4.675 = 8.275 kN/m2

1. Tnh ton khung ngang vi b=3.5m

- Ti trng phn b u tc dng ln khung: q1=Qxb=8.275x3.5=28.96 kN/m

Ta c: + Chiu dy lp Btng bo v l 15mm

+ ng knh thp thng s dng: 12

q1=28.96 kN/m

P Pe1

e2e3

= 85 15 12 12 = 46 = 46 = 46 = . ( ) = . . = 2570.7 ( ) = . ( ) = . . . = 1062.4 ( ) - Ta c: . c = 1860 N/mm2 = = ( ) ( / ) = 1382.1 14 = = ( ) ( / ) = 571.2 6

2. Tnh ton khung dc vi b= + . =5.75m

- Ti trng phn b u tc dng ln khung: q2=Qxb=8.275x5.75=47.58 kN/m

= 34 = 34 = 34 = . ( ) = . . . = 1428.6 ( ) = . ( ) = . . . = 1071.42 ( ) = ( ) ( / ) = 768.06 8 = ( ) ( / ) = 576.03 6

q2=47.58 kN/m

Pe1

e2e3

Pe1

e2