chapter 6 design detailing of major steel components
DESCRIPTION
Detailing rulesTRANSCRIPT
6. Design detailing of major steel
components
This chapter gives a comparative study of detailing practices for major steelcomponents such as beams, girders, columns, trusses, and various fastenings.Three major codes are considered and they are based on British, European andAmerican practices. Both bolted and welded connections or fastenings aregiven as practised under the BS 5950, EC3 and AISC and LRFD Codes.
67
6.1. Beams and girders
Fig. 6.1.1. Notching of flanges—bolted connection, all beams gradeS275 (based on EC3 specifications)
68
STRUCTURAL DETAILING IN STEEL
Fig. 6.1.2. Beam fabrication details (based on AISC specifications)
69
DETAILING OF MAJOR COMPONENTS
Fig. 6.1.3. End plate shear connections of wide flange beams—boltedand welded connections (based on AISC specifications)
70
STRUCTURAL DETAILING IN STEEL
Fig. 6.1.4. Bolted framed beam connection: (a) semi-rigid connection; (b) moment connection(based on AISC/LRFD specifications)
71
DETAILING OF MAJOR COMPONENTS
Fig. 6.1.5. Sloped and canted beam connections (based on AISC/LRFDspecifications)
72
STRUCTURAL DETAILING IN STEEL
Fig. 6.1.6. Web reinforcement of coped beams (based on AISC/LRFDspecifications)
73
DETAILING OF MAJOR COMPONENTS
Fig. 6.1.7. Sloping beam connections using Saxe seats (based on AISC specifications). Figure usedwith permission of The Lincoln Electric Company
74
STRUCTURAL DETAILING IN STEEL
Fig. 6.1.8. Miscellaneous connections assembled with Saxe seats andclips (based on AISC specifications). Figure used with permission of TheLincoln Electric Company
75
DETAILING OF MAJOR COMPONENTS
Fig. 6.1.9. Flexible and rigid connections: (a) beam–seat connections—flexible; (b) beam-to-column flange connections—moment-resistant;(c) beam-to-column web connections—moment-resistant (based onAISC/LRFD specifications)
76
STRUCTURAL DETAILING IN STEEL
Fig. 6.1.10. Beam–column welded and bolted connections: (a) weldedconnections; (b) bolted connections (based on AISC/LRFD specifica-tions)
77
DETAILING OF MAJOR COMPONENTS
Fig. 6.1.11. Beam–column seated and spliced connections: (a) endbeam to column welded connection; (b) beam–column connection withsplice beam connection (field/shop welding) (based on EC3 specifica-tions)
78
STRUCTURAL DETAILING IN STEEL
Fig
.6.1
.12.
En
d b
eam
–co
lum
n c
on
nec
tio
n—
pro
ject
ed v
iew
s (b
ased
on
BS
5950
sp
ecifi
cati
on
s)
79
DETAILING OF MAJOR COMPONENTS
6.1A. Detailing of welded plate girders
Fig. 6.1.13. Spandrel beam to columns (based on BS 5950 specifications)
80
STRUCTURAL DETAILING IN STEEL
Fig. 6.1.13. Continued
81
DETAILING OF MAJOR COMPONENTS
Fig. 6.1.14. Beam to column connection—all welds 6–8 mm (based on EC3 specifications)
82
STRUCTURAL DETAILING IN STEEL
Fig. 6.1.15. Sample shop detail drawing—beams (based on AISC specifications)
83
DETAILING OF MAJOR COMPONENTS
Fig
.6.1
.16.
Det
ailin
g o
f ty
pic
al b
eam
wit
h b
olt
ed a
ng
le c
leat
s: a
ll b
olt
s ar
e H
D20
gra
de
4.6;
th
e b
eam
is
S27
5; a
ll an
gle
s/ch
ann
els
S27
5 (b
ased
on
EC
3sp
ecifi
cati
on
s)
84
STRUCTURAL DETAILING IN STEEL
Fig
.6.1
.17.
Su
mm
ary
of
pla
te g
ird
ers
—b
rid
ge
(AW
S a
nd
AA
SH
TO
sp
ecifi
cati
on
s)
85
DETAILING OF MAJOR COMPONENTS
Fig
.6.1
.18.
Su
mm
ary
of
pla
te g
ird
ers
—b
uild
ing
(A
ISC
an
d A
WS
sp
ecifi
cati
on
s)
86
STRUCTURAL DETAILING IN STEEL
Fig. 6.1.19. Plate girders (symmetrical flanges), welded (based onBS 5950 specifications)
87
DETAILING OF MAJOR COMPONENTS
Fig. 6.1.20. Beam splice details over supports (continuous over threespans) (based on AISC and AASHTO specifications). From StandardSpecification for Highway Bridges, Copyright 1996, by the AmericanAssociation of State Highway and Transportation Officials, Washington,D.C. Used by permission
88
STRUCTURAL DETAILING IN STEEL
6.2. Columns and portal frames
Fig. 6.2.1. Types of column, holding down bolts and gantry girders (BS 5950 specification)
89
DETAILING OF MAJOR COMPONENTS
W column splices
Two cases are described below, namely splice plates shop welded and field bolted and shop weldedand field welded.
First caseFlange plates shop welded, field boltedDepth DU and DL nominally the same
Case 1
DL=(DU+ 14) to (DU+ 5
8)No fills.Furnish sufficient 21
2 �18 strip shims to
obtain 0 to 116 clearance on each side.
*Splice plates, welds and fasteners:
(1) Select width of splice plate, number and gage offasteners, and length LU in accordance with uppershaft size.
(2) Select thickness of splice plates, size A andlengths (X and Y ) of welds and lengths LL inaccordance with lower shaft size.
(3) Add LU+LL to obtain length of splice plates.
Case 2
DL=(DU �14)
DL=(DU �18)
DL=DU
DL=(DU+ 18)
Fills on lower shaft.
*Splice plates, welds and fasteners:
Same as for Case 1, except use weld size (A+t) onlower shaft.
FILLS (shop welded under splice plates):Fill thickness t:
Where DL=(DU �14), use 3
16
DL=(DU �18), use 3
16
DL=DU, use 18DL=(DU+ 1
8), use 18Fill width: same as splice plate.Fill length: (LL �2)
Case 3
DL=(DU+ 34) and over.
Fills on upper shaft, minimum welds.
*Splice plates, welds and fasteners:
Same as for Case 1.
FILLS (shop welded to upper shaft):Fill thickness t: 1
2(DL �DU )�18 or �
316, whichever results
in 18-in. multiples of fill thickness.Weld size B:
Weld length: (LU �14)
Fill width: Width of splice plateFill length: (LU �
14)
Second caseFlange plates shop and field weldedDepth DU nominally 2 in. less than depth DL
Case 4
Fills on upper shaft, developed for bearing.Fill width less than upper shaft flange
width.
*Splice plates and splice welds:
Same as Case 1.
FILLS (shop welded to upper shaft):Fill thickness: t: 1
2(DL �DU )�116
Weld size B:
Max.: 516 (preferred) or (t�
116) or t,
Weld length LB � (Af fp )/2fR � (L/2+112) in which
Af=finished contact area of one fill, fR=allowableshear value of one linear inch of weld, size B, andfp=computed bearing stress in fill
Fill widthMin.: (Splice plate width)+2NMax.: (Upper shaft fig. width)�2M
Fill length: LB
Case 5
Fills on upper shaft, developed for bearing.Fill width greater than upper shaft flange
width.Use Case 5 only when spaces M and N,
Case 4, are inadequate for welds B andA, or when fills must be widened toobtain additional bearing area.
*Splice plates and splice welds:
Same as Case 1.
FILLS (shop welded to upper shaft):Fill thickness: 1
2(DL �DU )�116
Weld size B:
Max.: 516 (preferred) or (TU �
116) or TU .
Weld length LB : Same as Case 4Fill width: (Splice plate width)+2N, or (Upper shaft
figure width)+2MRound greater value up to next quarter inch.
Fill length: LB
Note:1. *Min. AISC, ASD and LRFD specification.2. 1 inch=25.4 mm.3. If LB=fill length is excessive place weld size B across and offill and reduce LB by 1
2 or to L/2+112.
Disregard return welds in Case 2.
Fig. 6.2.2A. W column splice construction examples
90
STRUCTURAL DETAILING IN STEEL
Fig. 6.2.2B. Miscellaneous column splices—projected view (AISCspecification)
91
DETAILING OF MAJOR COMPONENTS
Fig. 6.2.3. Built up compression members—projected view (AISCspecification)
92
STRUCTURAL DETAILING IN STEEL
Splice Plate Fasteners Welds
Column Size Length No. LengthWidth Thk. of Gage Size
LU LL Rows G A X Y
W14�455 & over 14 58 121
4 9 3 1112
12 5 7
W14�311 to 426 12 58 121
4 8 3 912
12 4 6
W14�211 to 283 12 12 121
4 8 3 912
38 4 6
W14�90 to 193 12 38 91
4 8 2 912
516 4 6
W14�61 to 82 8 38 91
4 8 2 512
516 3 6
W14�43 to 53 6 516 91
4 7 2 312
14 2 5
W12�120 to 336 8 12 91
4 8 2 512
38 4 6
W12�53 to 106 8 38 91
4 8 2 512
516 3 6
W12�40 to 50 6 516 91
4 7 2 312
14 2 5
W10�49 to 112 8 38 91
4 8 2 512
516 3 6
W10�33 to 45 6 516 91
4 7 2 312
14 2 5
W8�31 to 67 6 38 91
4 7 2 312
516 2 5
W8�24 & 28 5 516 91
4 6 2 312
14 2 4
Gages shown may be modified if necessary to accommodate fittings elsewhere on the columns.
Fig. 6.2.4. Column member splices (based on AISC/ASD specifications, adapted by LRFD)
93
DETAILING OF MAJOR COMPONENTS
Fig. 6.2.5. Column splice fabrication details (based on AISC/LRFD specifications). Figure used withpermission of The Lincoln Electric Company
94
STRUCTURAL DETAILING IN STEEL
Fig. 6.2.6. Column bases (based on EC3 specifications)
95
DETAILING OF MAJOR COMPONENTS
Fig. 6.2.7. Miscellaneous column base details (based on AISC and EC3specifications). Figure used with permission of The Lincoln ElectricCompany
96
STRUCTURAL DETAILING IN STEEL
Fig. 6.2.8. Miscellaneous column base details (based on AISC/BS 5950specifications)
97
DETAILING OF MAJOR COMPONENTS
Fig. 6.2.9. Column base details (based on AISC and EC3 specifications)
98
STRUCTURAL DETAILING IN STEEL
Fig. 6.2.10. Multi-storey building column: (a) column schedule; (b) key plan grid (based on BS 5950and EC3 specifications); (c) detailing
99
DETAILING OF MAJOR COMPONENTS
Fig. 6.2.11. Column detailing practice—trussed column (based on BS 5950 and EC3 specifications)
100
STRUCTURAL DETAILING IN STEEL
Fig. 6.2.12. Design details of portal frames and projections (based on BS 5950 specifications): (a)–(c)isomeric views; (d) sectional elevation
101
DETAILING OF MAJOR COMPONENTS
Fig. 6.2.13. Structural details of portal frames (based on BS 5950 and EC3 specifications)
Fig. 6.2.14. Pre-set of portal frames—fabrication drawing (based on BS 5950 and EC3 specifica-tions)
102
STRUCTURAL DETAILING IN STEEL
Fig
.6.2
.15.
Co
mp
ute
r-ai
ded
str
uct
ura
l det
ails
of
po
rtal
fra
mes
—M
aste
rSer
ies
(bas
ed o
n B
S59
50 s
pec
ifica
tio
ns)
103
DETAILING OF MAJOR COMPONENTS
6.3. Trusses, lattice girders and trussed frames
Fig. 6.3.1. Types of truss and lattice girder and truss joints—isometricviews
104
STRUCTURAL DETAILING IN STEEL
Fig. 6.3.2. Chord and bracing sections and details (based on BS 5950,EC3 and AISC specifications)
105
DETAILING OF MAJOR COMPONENTS
Fig. 6.3.3. Node points—bolted construction (based on BS 5950 andEC3 specifications)
106
STRUCTURAL DETAILING IN STEEL
Fig
.6.3
.4.
Det
ailin
g o
f b
olt
ed t
russ
(b
ased
on
EC
3 sp
ecifi
cati
on
s)
107
DETAILING OF MAJOR COMPONENTS
Fig. 6.3.5. Node points—welded construction of an arched truss (based on Lincoln Electric Co.specifications). Figure used with permission of The Lincoln Electric Company
108
STRUCTURAL DETAILING IN STEEL
Fig. 6.3.6. Typical roof truss and details (based on AISC and Lincoln Electric Co. specifications).Figure used with permission of The Lincoln Electric Company
109
DETAILING OF MAJOR COMPONENTS
Fig. 6.3.7. Welded truss and details (based on AISC and Lincoln Electric Co. specifications). Figureused with permission of The Lincoln Electric Company
110
STRUCTURAL DETAILING IN STEEL
Fig
.6.3
.8.
Det
ailin
g o
f a
bo
lted
ro
of
gir
der
(b
ased
on
EC
3 sp
ecifi
cati
on
s)
111
DETAILING OF MAJOR COMPONENTS
6.4. Welded tubular steel construction
Fig. 6.4.1. Welded tubular steel construction (based on Lincoln ElectricCo.). Figure used with permission of The Lincoln Electric Company
112
STRUCTURAL DETAILING IN STEEL
Fig. 6.4.2. Welded tubular steel splices (based on AISC specifications). Copyright: American Instituteof Steel Construction, Inc. Reprinted with permission. All rights reserved
113
DETAILING OF MAJOR COMPONENTS