VAI TRO HE GIANG COT, GIANG MAI NHA CONG NGHIEP BANG THEP DUdi TAC DUNG CUA
Liic HAM NGANG CAU TRUC
Do Trong Quang', f)o Thj Thu Thuy**
Tom tdt
Bdi bdo trinh bdy vai trd cua he gidng cdt, gidng mdi, xd go mdi trong sU ldm vi&e khong gian cda khung thep nhd cdng nghi$p mgt tdng dudi tdc dung cda lUc hdm ngang cdu true Tmax He ket cdu khdo sdt cda 4 cong trinh vdi nhip vd sdc tdi cdu true khdc nhau. Vdi moi cong trinh, 3 tinh hudng dUdc dUa ra phdn tich gom: M khung phang, hi khung khong gian cd vd khdng eo sU tham gia cda gidng cot, gidng mdi, xd go mdi. Ngi lUc tai vai cot, chdn cot vd chuyen vi dinh cot da dUdc phdn tich bdng phdn mem SAP2000, tii do ed cdi nhin tong quan hdn ve sU ldm viee khong gian cua kit cdu nhd cong nghiip. Ket qud nghien cdu dd chi ra rdng ngi lUc do lUc hdm cua cdu true, chuyen vt d dinh cot do lUc hdm ngang cdu true gidm trong sd dS khung khdng gian. Ket qud nghien cdu cd thi dp dung vdo thUc ti nhdm tiit kiem nguyen vat lieu vd gidm gid thdnh cho cong trinh.
Tttkhod: khung khdng gian, khungphang, ket cdu, nhip nhd, tdi trgng.
I. Gidi thieu chung
Tnide ddy, khi cong nghi th6ng tin chiia phat trien, eae phdn mem tinh toan npi liic kit eau eong trinh eon ehha pho biln nln vile phan tieh npi lUe eua mpt khung khong gian
'TS.. Khoa Xay di^ng.
"ThS., Phong DSo tao.
hicfng doi phiic tap. Dong thdi, cae nha eong nghiip thu6ng co ehieu dai 16n hdn nhieu lan so vdi ehieu rong nln dp eiing theo phhOng dpe nhd la 16n hPn so vdi phiiOng ngang nhd.
De dPn gidn cho viec tinh toan, hau hit cac tai lieu hifdng dan thiet k l khung theo so do khung phang, bo qua sii lam vile eiia he giang, he xd gd mai. Vile ndy se dan din sai so gifla tinh todn vd npi liic thiie t l ciia khung. Cde loai tdi trpng nhil tinh tdi, boat tdi, tdi trpng gio khi phdn tich coi Id tdc dung len tdt cdc khung do dd khdng thay rd diide vai tro cua he giang, he xa gd mai. Liic ham cua cau true si nguy hiem nhdt khi coi tde dung vao mdt khung ngang. Tuy nhiln do he thong giang nen liic ndy se diidc truyen sang cdc khung bin canh vd cac khung cimg chiu liic. Vile tinh todn nay tiidng doi phiie tap nln vai tro eiia he giang, xa gd thiidng khdng diidc tinh todn kl.
Mat khac, trong nhflng nam gan day, nhieu cdng trinh, nhd may, khu cdng nghiip ldn da diide xay diing tren khap mpi miln dat niide. Hau het deu sii dung he khung kit edu thep tiin che nham nit ngan thdi gian thi cdng, khdng gian sii dung ldn va de dang md rpng quy md hay day ehuyin cdng nghe.
Hien nay, vctl sii phdt trien ciia edng nghe thdng tin, mdy tinh, sii ra ddi cCia cac phan mim phan tieh ndi liic ket cau sfl dung phhdng phap phan tii hflu ban Id edng eu hflu ich, lam giam di sii phflc tap trong qua trinh tinh npi
liie eua khung khdng gian, tfl do md ra cho ehung ta nhiing hiidng tinh todn mdi sdt vdi thiie te ldm viee eua cdng trinh hdn.
Vi vay, vile tinh toan ndi liie eua kit edu khung cd kl den h i giang, he xa gd mai sfl dung phfldng phdp phan tich xet din sfl ldm
\qec khdng gian ciia kit cau la edn thiet.
II. Noi dung vaphiAmg phap nghien cuTU Tdc gid sfl dung phan mim tinh toan kit cdu SAP2000 d l tinh toan ndi lflc, ehuyin vi dinh edt eua nha edng nghiep bang thep ed k l den sfl tham gia eua he giang edt, giang mai, xd gd vd dam eau true ddi vdi sfl ldm viec khdng gian efla kit cau cdng trinh. De thay ro dflde vai trd eua hi giang edt vd ddm cau true, giang mdi vd xa gd mdi, tdc gid tap trung vao phdn tich npi liic khung ngang do li;ie ham ngang cua eau true T^__^ vdi 3 trfldng hdp nhfl sau:
1. Khung ngang theo sd dd khung phang (sd dd 1) ddac thi hiin trln Hinh 2.2.
2. Khung ngang theo sd dd khung khdng gian khong cd he giang mdi va xa gd mai (Sd dd 2) dflpe thi hiin trln Hmh 2.3.
3. Khung ngang theo sd do khung khong gian cd he giang mai vd xd gd mdi (Sd do 3)
dfldc the hien trln Hinh 2.4
Vdi mdi sd dd nlu trln, 4 trfldng hop khae nhau vl nhip nhd (L) vd sfle nang cdu true (Q) cfla nhd edng nghiep sfl dung de tinh toan ndi Ifle, ehuyin vi dinh edt bao gdm:
- Khung nha cdng nghiip 1 tang, 1 nhjp CO chieu ddi L = 21m, sflc true Q = 6,3T.
- Khung nha cdng nghiip 1 tang, 1 nhip cd chieu dai L = 24m, sfle true Q = lOT.
- Khung nhd cdng nghiip 1 tang, 1 nhjp ed ehilu ddi L = 27m, sflc true Q = 20T.
- Khung nha edng nghiep 1 tang, 1 nhip cd chieu dai L = 21m, sfle true Q = lOT.
Nha ed chilu eao cdt Id 9m, ehilu dai ciia nha la 1 IxB = 11x6 = 66 m, vd gid dinh cong trinh dflpe xdy dflng tai khu vflc co dp Ifle gio tmhWo=150kgf/m^
Cae kit qud thu dfldc tfl pham mem khi phdn tich ndi lflc khung ngang cua 3 sd dl se dfldc so sdnh, danh gia de dfla ra kit ludn.
Gia tri tai trpng tae diong Iln cong trinh bao gom tai trpng thfldng xuyIn, hoat tai mai, tai trpng gid, tai trpng cau true dfldc tinh todn vk trinh bay trong Bang 2.1:
Bdng 2.1. Cia tri cdc tai trpng tdc dung lin cong trinh
T i i trong
Hnh til
cat Dam ValcDt Hoat til mil
0™
».i, T™
Gid ngang
at
Dam Cot Dam
L= 2 1 , 0 = 6,3 SOOkgf 99,5kgf/m
900kqf 2]5ki;f/m 1344;k9f
« l l k q f 475kgf q=910,6kqf/m g'=S80,3kgf/m W=5«6kgf;m W'=«Okqf/m 4SSkgf/m S04,6kgf/m
Tnidng Eitrp nha cong nghiip co nhjp L(m),
vaorn
L=24,Q=10 500kq(
99,5kqf/m SOOkqf USkgf/m 23648kgf 764Skqf 586kgf q-910,6kgf/m q'=S80,3kqf/m W=586kgf/m W=460kgf/m 455kqf/m 804,6kgf/m
U 27,0=20 SOOkqf 99,5kqf/m
900kqf 235kgf/m 3S22Skqf 10006kqf 1478kgf q=910,6kqf/m q'=580,3kqf/m W=S86kgf/m W=460kqf/m 455kqf/m 804,6kqf/m
f
L=21,»=11I SOOkqf 99,Skqf/ni
900kqf 23Skqf;m 17217kqf 46S0kqf 557kqf o=910,6kqf/m q'=S80,3kqf/m W=586lqSm W ' = 4 « I I W H M
4 S S k q n ( ^ ^ 804,6koeiinBI
4 I TRl/flNGOAl HOC H A I PHdNG
Trong dd:
Dmai. Dmin: Ap Iflc dflng ldn nhat va nhd nhat cua cau true Iln vai cdt.
Tmai: Lfle ham ngang ldn nhat cua cdu true.
q, q': Tai trpng gid tdc dung Iln edt phia gid day va gid hiit
W, W : Tdi trpng gio tac dung Iln xd mai.
Hinh 2.1. Tiet dien cda cot vd ddm mai Dam mai vd edt khung sfl dung tilt diln td h(?p thep hinh chfl I dfldc the hien trln hinh 2.1. Dam mdi eo kich thfldc thay ddi, khoang bien ddi tilt diln each dau edt mdt doan (0,35 - 0,4)L/2. Tilt diln phan dam mai edn lai lay khdng ddi. Cdc kich thfldc ed ban cua tiet dien edt vd ddm ehfl I dfldc trinh bay trong Bdng 2.2
Bdng 2.2. Kick thUdc tiet dien cot va ddm Tiet
dien
Cot
Oau dam mai
Cuoi dam mai
Khip nha 1=21 m
h=500mm bf=250mm tf=10mm tw=8mm h=S00mm bf=250mm tf=10mm tw=8mm h=3S0mm bf=250mm tf=10mm tw=8mm
fil l
U4mh=600mm bf=250mm tf=10mm tw=8mm
f 5| |
L=27m h=500mm bf=250mm tf=10mm tw=8mm h=600mm bf=2S0mm t^lOmm tw=8mm h=350mm bf=250mm tf=10mm tw=8mm
Hinh 2.2. Saf do khung ngang (nhjp nha L= 21m, tdi cdu true Q= 6,37)
Hinh 2.3. Stfdo khung khong gian khong cd hi gidng va xa go mdi (nhip nhd L=21m, tdi cdu true Q= 6,3T)
Hmh 2.4. Sado khung khong gian co be thong gidng mdi vd xd go mdi (Nhjp nha L= 2 Im, tdi cau true Q= 6,3T) Sd dd khung phang vd khung khdng gian
cua khung thep nha cdng nghiip:
Ili. Ket qua phan tich noi lUc khung ngang Ndi lflc trong khung ngang flng vdi 3 sd do dflde xdc dinh vcti tflng lo^ tdi trpng da dflde ehudn bi trfldc (trinh bay trong Bang 2.1) bang phan mim SAP 2000. Liln kit gifla cae thanh giang cdt, giang mai vdi kit eau khung dfldc eoi Id khdp. Lien kit gifla xd gd vd dam mdi eung dfldc md hinh hod la khdp. Kit qud tinh toan ndi liie tai edc tilt dien dac trflng nhfl ehdn edt, vai cot va chuyen vi dinh cdt dflde dfldc tdng hdp tdm tat trong cac bang tfl bang 3.1 din bdng 3.5.
Bdng 3.1. Mdmen tai vi tri vai cot va chan cot do lUcham ngang cau true Tmax
Hi khung
Khung phang ISO Sol)
Khung khong gian khong CO
hexa (Solo 2)
Khung khong gian CO he
xigo (So 36 3)
Vjtn tiet diin
Vai cot Chin
tot
Vai cot Chin cot Vai cit Chan
cot
Momen do life ham ngang cau true (Kgf.m) t=21m
0 =
-389.4 1556.8
-S73.4 1539.4
-573.4 1539.4
L-24ni
10T
-691.1 182S.5
-672.4 1805.2
-672.4 1805.2
l=27m Q = 20T
-1736.8 5082.4
-1688.8 5032.9
-16889 5032.8
L = 2 1 m Q = 10T
- 6 9 9 . 4 1976.1
- 6 8 0 . 1 19S5.S
- 6 8 0 . 1 1955.S
Cae sd lilu tinh toan trong bang 3.1 ehi ra rang vdi nhip nhd va tdi trpng nhfl nhau, md men do lfle ham ngang cau true tai vai cdt va ehan cdt cua sd dd khung phang cd gid tri ldn nhdt, gia tri ndy cd xu hfldng giam khi xet din sfl lam vile khdng gian cua khung vd ed xu hfldng gifl nguyen gia tri hoae giam nhe khi xet them sfl lam vile cua he giang mai va xd gd mdi. Cu thi, vdi trfldng hdp nhip nha L=21 m.
sflc tai eau true Q=6,3T, mdmen tai vai cot giam lan Ifldt tfl -589,4 l^fm xuong -573,4 kgfm tfldng flng vdi khung d sd dd 1, sd do 2, gid tri nay gan nhfl khdng ddi khi so sanh gifla sd do 2 vd Sd dd 3. Dl ed cai nhin trflc quan va thdy rd hdn sfl thay ddi gia tri md men tai vai edt flng vdi tflng loai sd dd, sd lieu tai bang 3.1 dflde xay dflng dfldi dang do thi the hien tren Hinh 3.1. (1) Mdu xanh dfldng, (2) ma,u do, (3) mau xanh la cdy lan Ifldt the hiin md men ehan edt eua sd dd khung phang, sd do khung khdng gian khdng co h i xd gd va sd do khung khdng gian cd he xa gd mdi.
Ngi lye do Tmax gay ra tgi chSn cot j , L=21m,Q=20t I
i L=2lm,Q=20t I ' L=21m,Q=10E I I L=Zlm, Q=6,3t I
0 2000 4000 61
• s a do 3 • s o (36 2 • sa do 1
Hinh 3.1. Bieu do so sdnh npi lUe khung phSng, khung khong gian khong co hi xi go vd khung khong gian eo hixa g6 tai chan e6t
Sd lilu d Bang 3.2 thi hien gia tri chuyen vi tai dinh cdt flng vdi tflng sd d6.
Tfldng tfl nhfl gid tri md men, ehuyin vi tai dinh edt cung cd xu hfldng giam dan tii sd do 1 den sd dd 3, tuy nhien mflc dd giam manh ed the thdy rd hdn khi so sdnh giiJa trfldng hdp khung phang va khung khong gian. Mfle dp giam cham di khi so sanh chuyen vi cua sd dd khung khdng gian cd va khdng ed he xd gd mai.
Bdng 3.2. Chuyen vi dinh ept do lue bdm ngang cau true Tmax gay ra
1
1 He khung 11 Khung 1 pliang (SoOol) 1 Khung 1 khongglan 1 khongcvhe xi(SlIlo2) 1 Khung 1 khong gian 1 cohexago 1 (59963)Ciiuyen vj dinbG&t(ign) L=21ni
Q=6,3T
3.38
3.36
3.36 L=24ni (1 = 1(11
4.39
4.37
4.37 U 2 7 n i 0 = 20T
11.43
11.39
11.39 U 2 1 m 5 = 1 0 1
3.96
3.94
3.94
Sd lieu d Bang 3.2 cho thay vdi ca 4 trfldng hdp nhip nha va sflc nang cau true khdc nhau, ehuyin vi dinh edt cua sd dd khung khdng gian khi khdng xlt den sfl cd mat cua xd gd mai nhd hdn so vdi khi tinh todn theo sd dd khung phang. Vi du vdi trfldng hdp nhd nhip L=27m, eau true Q=20T, chuyen vi dinh edt theo so dd 1 Id 11.43mm trong khi chuyen vi la li.39mm theo sd do vd gia tri nay khdng ddi khi xet Sd dd 3.
IV. Ket luan
- So sdnh ndi liie eua Idiung ngang nhd cdng nghiep do lflc ham ngang edu true Tm„
gay ra gifla 3 loai so do:
+ O sd dd khung khdng gian khdng ed he giang mdi vd xd gd mai, md men 6 vai cdt vd ehan edt gidm trung binh 2,74% so vdi sd do khung phang.
+ O sd do khung khdng gian ed he giang mai va xa gd, md men 6 vai edt vd ehdn cdt khdng thay ddi so vdi sd dd khung khdng gian khdng ed he giang mdi va xa gd.
- So sdnh chuyen vi dinh edt do lfle ham ngang cau true Tma gifla 3 loai sd do (sflc true Q< 20 tan va khodng each nhip L<27m):
+ Chuyen vi dinh edt cua sd dd khung phang ldn hdn khodng 0,67% so vdi sd dd khung khung gian.
+ Khi xet them he giang mai vd xd gd mdi vao vko qua trinh tinh toan chuyen vi dinh cdt eho thay anh hfldng cua he thong xa gd mai la khdng dang ke khi sflc true cua cau true nhd va nhip cd dp ldn trung binh.
TAI LIEU THAM KHAO [1] Pham Vdn Hdi, Nguyen CJuang Viln, Pham
Van Tii, Lflu Van Tfldng, Kit cdu thep - cdu kien cd ban, RXB Khoa hpe va ka thuat, 2006.
[2] Hoang Van Quang, Tran Manh Dung, Nguyen Qude Cfldng, Thiet ki Idiung thep nhd cong n^iep, NXB Khoa hpe Id thuat, 2010.
[3] Doan Dinh Kiln, Pham Van Tfl, Ngi^ln Quang Vien, Thiet kekit cdu thep rdid cong n^iip, NXB Khoa hpe va Id thudt, 2003.
[4] Pham Minh Ha, Doan Tuyet Ngoc, Thiet ke Idiung thep nhd cong nghiep mgt tdng mgt nhip, NXB Xdy dflng, 2008.
[5] Pham Vdn Hdi, Nguyen Quang Viln, Pham Vdn Tfl, Doan Ngpe Tranh, Hodng Vdn Quang Kit cdu thep 2 - Cdng trinh ddn dung vd cdng nghiep, NXB Khoa hpe va Id tfiudt, 1998.
[6] Tieu ehudn TCVN2737-2005.
[7] Pham Vdn Dien, Trfldng Thanh Sdn, Hd Thanh, Hai Minh, SAP2000 versionlO Thdc hdnh phan tich vd thiit ki kit cdu, NXB Khoa hpc ki thudt, 2008.
THE ROLES OF BRACE SYSTEM AND ROOF PURLINS IN INDUSTRIAL
STEEL FRAME STRUCTURES SUBJECTED TO HORIZONTAL BRAKING FORCES OF A CRANE Abstract: The paper presents the role of brace system and roof purlins in industrial steel frame structures subjected to horizontal braking forces of a crane !„,„ The investigation includes 4 models of buildings with the different spans and crane lifting capacities. For each model, 3 type structures have been analysied including: plane frame structures, space frames with and without column, roof bracings and
roof purlins. Internal forces and displacemenU of frame columns are calculated by the profesional software SAP2000, which leads to better overview about the performance of industrial building frames. Research resulu have indicated that the column internal forces and displacements caused by Tmai are reduced in comparison between plane frame and space frame structures eases. The research results can
be applied in practice to save materials and reduce costs for projects.
Keywords: space frame, flat frame.
structure, pace the house, load.
1 I Tfil/rtMr nai
