III II I I 00 I 0 I l 02 l 03 l 04 105 l 06 l 07 108 I 09 200 20 l 202 203 204 205 206 207 208 209
KIEM TOAN DAM CHU
3.2.2. M~tdt ngang dftm thep lien hQ'p ban BTCT (tai trQng da
h~n) - Ti8t di~n chju momen duO'ng
Bang 13. D~c trung hinh hQc dftm thep lien hqp ban BTCT du6i tac dl,lng tai tr9ng dai h(;ln,' 3n = 24
cfiu M~t c~t Di~n tich ThOng s6 Momen quan tinh
ki~n B€r('mg Chi€uday A y Ay !,,, I (mm) (mm) (mm2) (mm) (mm3) (mm./) (m1~-1) Canh tren 360 20 7.200 545 3.924.000 2.138.580.000 240.000 Ban b1,mg l.Q70 12 12.840 0 0 0 1.225.043.000 Canh duoi 410 32 13.120 -551 -7.229.120 3.983.245.120 1.119.573 BMC 115 200 22.917 705 16.15<?.250 .11.390.156.250 76.388.889 Vutchfr 15 50 750 580 435.000. 252.300.000 156.250 nh~t Tfing c(>ng 56.827 13.286.130 19.067.229.082
Khoang each tutr9ng tam m~t dt t6i trl,lC trung hoa ban bl,lng:
+ LAy
Yt,r = LA = 233, 8mm
Momen quan tinh m~t c~t d6i v6i tr\lc trung hoa cua m~t c~t:
11r =Ix -Y1r L:Ay = 15.960.918.951mrn4
. Khoang each tu tf\lC trung hoa m~t c~t t6i mep tren dftm thep:
· Y~,~· =0,5h1v+t1 ,--y;,r =32l,2mm
Khoang.cach tu tf\lC trung hoa m~t dt-tai mep du6i dftm thep: .
y~;. = O,Shw +tb + Y7.r = 800,8mm
Momen finh m~t c~t d6i v¢i trvc di qua mep tren dftm thep:,
I+ - IL. - 3 S11. -, - . I+ - -49.69l.679mm S11. -, - . I+ - -49.69l.679mm Yu (123} (124) (125) (126) (127)
Momen tinh m~t dt ddi v6i tn,ic di qua mep du6i dfrm thep:
h+ _ l:r _ 3
s[,'l' ---;;:;:--19.93 l.193mm (128)
Y1,r
Khoang each tu tn,1c trung hoa m~t c~t t6i mep tren ban m~t cfru:
(129) Momen finh m~t dt ddi v6i tn,ic di.qua mep tren ban m?t cfru:
s;~; = 10: = 27.942.833mm3
Yu
(130)
3.2.3. M~t dt ngang dim thep lien hgp ban BTCT (tai trqng ng~n
h~;m) - Ti~t di~n momen duO'ng
C~u ki~n Canh tren Ban bµng Canh du6i BMC· Vut chu· nh~t
Bang 14. D?c trung hinh hQc dfrm th'ep lien hqp ban BTCT du6i tac dvng tai tr9ng ng~n hi.in, n = 8 .
M~tc~t Di~n Thongs6 Momen quan tinh
ti ch B~ Chi~u n?ng day A y Ay /"' I (mm) (mm) (lnm 2 ) (mm) (mm3) (1111114)· (m:n4): 360 20 7.200 545 3.924.000 2.138.580.000 240.000 1.070 12 12.840 0 0 0 1.225.043.000 410 32 ll120 -551 -7.229.120 3.983.245.120 1.119.573 344 200 68.750 705 48.468.750 34.170.468.750 229.166.667 45 50 2.250 580 1.305.000 '756.900.000 468.750 TdngcQng 104.160 46.468.630 42.505.231.860
Khoang each tu tr9ng tam m~t dt t6i tn,ic trung hoa ban bvng: ·
+ . IAY: 44·
Ysr = I A = 6, lmm ( 131) Momen quan tinh m?t dt ddi v6i trvc trung hoa cua m~t c~t:
Khoang each tu tn,ic trung hoa m~t c~t t6i mep tren dlim thep:
y~;. = 0,5hw +t1-y;r=108,9mm (133)
Khoang each tu tr\lc trung hoa m~t c~t t6i mep du6i dlim thep:
Y.~; = 0,5hw +th+ Y;r = 1.013, lmm (134)
Momen tinh m~t c~t d6i v6i tr\lc di qua mep tren dlim thep:
. l+
r+ _ ST _ 3
SsT - ----i:;:--199.998.00Smm (135)
Ysr
Momen tinh m~t dt d6i v6i tr\lc di qua mep du6i dlim thep:
h+ _ l.;T _ 3
SsT -~-21.492.166mm
YsT
(136)
Khoang each tu tf\lC trung hoa m~t dt tai mep tren ban m~t cliu:
y~'!" = 0,5hw +t1 +t11 +th - y;T = 358,9mm (137)
Momen tinh m~t c~t d6i v6i tf\lC di qua mep tren ban m~t cliu:
s~:.+ = l~~ =60.674.186mm3 (138)
Ysr
3.2.4. Momen dco - Ti~t di~n chju momen duO'ng
Momen deo, MP, phai duqc tinh b~ng momen do h,rc deo quay quanh tf\lC trung hoa deo gay ra. Cac h,rc deo trong phlin thep cua m~t c~t phai duqc. tinh v6i cuang d<) gi6i hf:lll chay cua cac ban canh, ban b\,lng va c6t thep tuang l'.mg. Cac h,rc deo trong phlin be tong chiu nen cua m~t c~t duqc tinh, theo bi~u do l'.mg su~t chiu nen hinh chfr nh~t phlin m~t c~t be tong v6i (mg su~t chiu nen b~ng 0,85fc. Bo qua phlin be tong chiu keo (D6.Dl).
Bo qua sv tham gia chiu Ive cua c6t thep ban m~t cliu trong vi~c xac dinh momen deo, khi xet thien v€ an to~m (D6.D 1 ). Xac dinh cac h,rc deo theo cong thuc:
D6i v6i vung betong ban m~t cliu:
~- =0,85J;/,beff =0,85x30x200x2750xl0-3
Khoang each tu tn,ic trung hoa m~t c~t t6i mep tren ddm thep:
Y,~;. = 0, 5hw + t, - Y;r = 108, 9mm (133)
Khoang each tu tf\lC trung hoa m~t c~t t6i mep du6i ddm thep:
Y,~; = 0,5hw +th+ Y;r = 1.013, lmm (134)
Momen tinh m~t c~t d6i v6i tn,ic di qua mep tren ddm thep:
I+ _ l,;]' _ 3
Ssr - ---;+ -199.998.005mm (135)
Ysr
Momen tinh m~t dt d6i v6i tr\lc di qua mep du6i ddm thep:
h+ l;T 3
Ss~ 1· = -·- = 21.492.166mm l'+
Ysr
Khoang each tu tf\lC trung hoa m~t dt tai mep tren ban m~t cdu:
Y.~: = 0,5hw +t, +t,, +tb -y,;r =358,9mm
Momen tinh m~t c~t d6i v6i tr\lc di qua mep tren ban m~t cAu:
s.~i.+ = 1;~~ = 60.674.186mm3
Ysr