107313 glass awning support engineering
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12 March 2014C.R. Laurence Co., Inc.
2200 E. 55th STLos Angeles, CA 90058-0923
SUBJ: CRL UNIVERSAL WALL MOUNTED GLASS AWNING BRACKET GAB24, GAB36, GAB48
The CRL universal wall mounted glass awning bracket utilizes stainless steel fittings to constructwall mounted cantilevered glass awnings using 9/16” two ply laminated tempered glass. The
system is intended for interior and exterior weather exposed applications and is suitable for usein all natural environments. The system may be used for residential, commercial and industrialapplications. The Glass Awning Brackets are designed for the following criteria: The design loading conditions are: Concentrated load = 50 lbs any direction, any location Uniform load = 25 psf vertical, live, wind (ASD level loads) or snow loadHigher uniform loads may be allowed depending on glass strength and size as shown herein.
Wind loads determined per ASCE/SEI 7-10 (2012 IBC) shall be adjusted to ASD level.
The glass awning is not intended to support significant concentrated live loads or personnel. Itshall not be used to walk, stand or step on.
The Glass Awning Brackets will meet applicable requirements of the 2006, 2009 and 2012International Building Codes, and 2010 and 2013 California Building Codes. Stainless steelcomponents are designed in accordance with SEI/ASCE 8-02 Specification for the Design of
Cold-Formed Stainless Steel Structural Members or AISC Design Guide 27 Structural StainlessSteel as applicable. Anchorages to wood are designed in accordance with the National Design
Specification for Wood Construction.Calculations PageSignature Page 2Awning dimensions 3Wall Mounting Bracket 4 – 5Wall Mounting Bolts/Anchors 5 – 6Allowable Bracket Loads 7 – 9Glass Strength 10 - 11Allowable Uniform Loads 12 - 13RB50F Glass Fitting 14Attachments – Bracket details 3 pages
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Signature Page:
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Signed 03/12/2014
42123
EDWARD C
ROBISON
EXP 12/31/2015
NO 63683
STATE OF
EXP 02/28/2015
E D W A
R DC. R O B
I S O N
H
A W A
I I U. S .
A .
LICENSED
PROFESSIONAL
ENGINEER
No. 11576-S
EXP 04/30/2016
EDWARD C
ROBISON
12/31/2015
7
5
6
18195PE
TE O F
WAS H I N G
73556
EDWARD C. ROBISON
EXP 09/30/2015FIRM #F-12044
EXP 12/31/2014
Edward C. Robison
088030
EXP 03/31/2015
EDWARD C.
EXP 03/31/2016
EDWARD C.
ROBISON
STRUCTURAL
No. 49757
EXP 06/30/2014
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CRL GLASS AWNING SUPPORT SYSTEMSupport hardware for flat panel awnings such as tempered laminated glass.
Dimensions a and c " 2”.Dimension b is either 17”, 29” or 41”Dimension B is # 24”, 36” or 48”Dimension d " 2”Dimension e based on allowable bracket loadand glass strength.
GAB24 Bracket
GAB36 Bracket
a
b
c
d e d
L
B
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Wall Mount
All bracket sizes use the same wall mount.Bracket bar is welded to the wall plate which
is bolted to the wall.
Fabricated from 304 stainless steel
Check strength of bar weld to wall plate:3/8” bevel weld with convex finish both sides.
Weld filler is E316
The weld will provide full penetration weldand develop full bar strength.
Tension strength of weld:
Pn = LtFua = 6”*0.5”*75ksi = 225k
Shear strength of weld at wall plate:Vn = (0.7-0.009L/t)tLFuaVn = (0.7-0.009*6/.75)(2*0.375”)*6”*75ksi = 211.95k
or:Vn = 0.75twLFxx = 0.75*(0.707*.375*2)*6”*75ksi = 178.96k
Vs = 0.65*178.96k = 116.3k # 0.55*211.95 = 116.57k
Allowable moment on the bracket based on weld strength:
Mn = 6”/2*116.3k = 348.9k”
Strength of bar at edge of weld:Z = 0.5”*6”2/4 = 4.5 in3
øMn = 0.9*4.5in3*30ksi = 121.5k” (bar yield strength controls load).
Maximum factored moment on the bar [1.2D+(1.6S or 1.6W)] or [1.2D+0.75(W+S)]or for uplift [0.9D+1.6W]Mu = 121.5k”
Design attachment to wall for the imposed moment:
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Maximum bolt tension based on plate bending:Plate bending will occur along a diagonal line from top
edge face of bar to edge of plate near other bolt.
bend length = 2.75”+2.75”* $ 2 = 6.64”Moment arm = 1.375”Z = 6.64”*0.52/4 = 0.415in3
øMnp = 0.9*45 ksi*0.415in3 = 16,807#”
Maximum bolt tension based on wall plate bending :
M = T*1.375” = øMn = 16,807#”T =16,807#”/1.375 = 12,223#
Check maximum bolt tension based on bracket platestrength:Bolt tension from %M about edge of wall plate:M = 0 = 4.625”*T*2 + 1.375”*(1.375/4.625)*T*2 +Mu
T = 121,000#”/[2*4.625+1.375*1.375/4.625] = 12,527#
Check strength based on anchor alternatives:1/2” Bolts:
At = 0.1419 in2
Fnt = 100,000 psi DIN 933-A2 or strongerøPn = øAtFnt = 0.75*0.1419in2*100,000psi = 10,642#Shear load will be carried by the bolts closest to the compression face of the couple which will
be lightly loaded in tension so no reduction for shear load is required.
For bolting to steel frame the maximum moment based on the bolt tension:Ms = 10,642#*[2*4.625+1.375*1.375/4.625] = 102,793#”
For bolting to wood:For through bolts the maximum bolt tension can be the same as for steel provided proper bearingplates are used on the nut side (3” x 3” x 1/4” plates or equivalent round washer).
For 1/2” Lag screws into Douglas Fir or Southern Pine:W = 378#/in,Minimum embedment depth of 5” (Lag into 6x beam or solid block)W’ = W*Cd = 375#”*1.15 for snow loads or 375#”*1.6 for wind loads (ASD level)T 5 = 5”*378#”*1 15 = 2 175#
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For bolting to concrete:Hilti Kwik Bolt TZ in accordance with ESR-1917.
1/2” diameter with 4” minimum embedment
Minimum conditions used for the calculations:f’c " 3,000 psiedge distance = 2.75” minimum2 bolt group (consider only anchors in full tension load)For concrete breakout strength:Ncbg = [ANc/ANco]!ed,N!c,N!cp,NNbANcg= (2.75”+1.5*4”)*(1.5*4”*2+3.25) = 133.4in2 For anchor groupANco= 9*42 = 144in2
Cac,min = 1.5*4” = 6
Cac = 2.5*4” = 10!ed,N = 1.0!c,N = 1.4 (post installed)!cp,N= 6/10 = 0.6 (ca,min #cac)
Nb = 17*1.0* $ 3000*41.5 = 7,449#Ncb = 133.4/144*1.0*1.4*0.6*7,449 = 5,798#based on concrete breakout strength.Pullout strength = 2*5,760# = 11,520#Steel strength:
Nts = 92,000psi*0.101in2 = 9,292# (each)
Concrete breakout strength in shear:
Vcb = Avc/Avco(!ed,V!c,V!h,VVbAvc = 3(ca1)*4” = 3(2.75”)*4” = 33.0Avco= 4.5(ca1)2 = 4.5(2.75)2 = 34.0!ed,V= 1.0 (affected by only one edge)!c,V= 1.4 uncracked concrete!h,V= $ (1.5ca1/ha) = $ (1.5*2.75/4) =1.016Vb= [7(le/da)0.2 $ da]" $ f’c(ca1)1.5 = [7(2/0.5)0.2 $ 0.5]1.0 $ 3000(2.75)1.5 =1,631#
Vcb = 33.0/34.0*1.0*1.4*1.016*1,631# = 2,252#
Factored moment:
Msc = 0.75*11,520*4.625” = 39,960#”Service MomentMs = 39,960”#/1.6 = 24,975”#
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For each size bracket determine maximum allowable loads on awning:
For GAB24:Glass width, B = 24”
Bracket weight: Db = [0.5”*(6+2)/2]*24”*0.28#/ci +2*1.3# = 16#For 1/2” laminated glass (1/4”+.05”+1/4”) Dg = 2*2.9+0.5 = 6.3 psf L = glass length (ft)MDf = 16#*12”+(6.3psf*2’*L/2)*12” = 192#”+(75.6L)#”Snow load or Wind (ASD level) loadSb = (Spsf*2’*L/2) = S*L plf
Wb = (Wpsf*2’*L/2) = W*L plf MbS = S*L plf*12”MbW = W*L plf*12”
For service loads (Steel or concrete)Ms = 1.2*(192#”+(75.6L)#”) + 1.6(S*L#*12”) = 230.4#”+90.72L+19.2S*L or
Ms = 1.2*(192#”+(75.6L)#”) + 1.6(W*L#*12”) = 230.4#”+90.72L+19.2W*L orMs = 1.2*(192#”+(75.6L)#”) + 0.75[(S+W)*L#*12”] = 230.4#”+90.72L+9(S+W)*L orMs = 0.9*(192#”+(75.6L)#”) + 1.6(W*L#*12”) = 172.8#”+68.0L+19.2W*L for uplift
Based on glass strength the maximum bracket spacing, e = 8’-0” for 1/2” glass and 25 psf wind
(ASD level) or snow load. The maximum cantilever length, d = 4’-0”
Check brackets based on the maximum allowable length of 16’ (4’+8’+4’) with 25 psf load.Ms = 230.4 + 90.72*16’ + 19.2*25psf*16’ = 9,362#” or
Ms = 230.4#”+90.72*16+9(25+25)*16 = 8,882#”Ms = 172.8#”+68.0*16 - 19.2*25*16 = -6,419#” for uplift
For allowable loads (wood)Ma = (192#”+(75.6L)#”) + (S*L#*12”) = 192#”+75.6L+12S*L orMa = (192#”+(75.6L)#”) + (W*L#*12”) = 192#”+75.6L+12W*L orMa = (192#”+(75.6L)#”) + 0.75[(S+W)*L#*12”] = 192#”+75.6L+9(S+W)*L orMa = 0.6(192#”+(75.6L)#”) + (W*L#*12”) = 115.2#”+45.36L+12W*L for uplift
Check brackets based on the maximum allowable length of 16’ (4’+8’+4’) with 25 psf load.Ma = 192#”+75.6*16+12*25*16 = 6,202#” orMa = 192#”+75.6*25+9(25+25)*16 = 6,882#” orMa = 115.2#”+ 45.36*16 - 12*25*16 = -3,959#” for uplift
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For GAB36:Glass width, B = 36”
Bracket weight: Db = [0.5”*{(6+2)/2*24”+12*6}]*0.28#/ci +2*1.3# = 26.1#For 1/2” laminated glass (1/4”+.05”+1/4”) Dg = 2*2.9+0.5 = 6.3 psf
L = glass length (ft)MDf = 26.1#*18”+(6.3psf*3’*L/2)*18” = 469.8#”+(170.1L)#”Snow load or Wind (ASD level) loadSb = (Spsf*3’*L/2) = 1.5S*L plf Wb = (Wpsf*3’*L/2) = 1.5W*L plf MbS = 1.5S*L plf*18” = 27SL
MbW = 1.5W*L plf*18” = 27SL
For service loads (Steel or concrete)Ms = 1.2*(469.8#”+(170.1L)#”) + 1.6(S*L#*27) = 563.76#”+204.12L+43.2SL orMs = 1.2*(469.8#”+(170.1L)#”) + 1.6(W*L#*27) = 563.76#”+204.12L+43.2WL orMs = 1.2*(469.8#”+(170.1L)#”)+0.75[(S+W)L#*27]=563.76#”+204.12L+20.25(S+W)L
Ms = 0.9*(469.8#”+(170.1L)#”) + 1.6(W*L#*27) = 422.82#”+153.09L+43.2W*L uplift
Based on glass strength the maximum bracket spacing, e = 8’-0” for 1/2” glass and 25 psf wind(ASD level) or snow load. The maximum cantilever length, d = 4’-0”
Check brackets based on the maximum allowable length of 16’ (4’+8’+4’) with 25 psf load.Ms = 563.76#”+204.12*16+43.2*25*16 = 21,110#”Ms = 563.76#”+204.12*16+20.25(25+25)*16 = 20,030#”Ms = 422.82#”+153.09*16 -43.2*25*16 = -14,408#” uplift
For allowable loads (wood)
Ma = (469.8#”+(170.1L)#”) + (S*L#*27”) = 469.8#”+170.1L+27S*L orMa = (469.8#”+(170.1L)#”) + (W*L#*27”) = 469.8#”+170.1L+27W*L orMa = (469.8#”+(170.1L)#”) + 0.75[(S+W)*L#*27] = 469.8#”+170.1L+20.25(S+W)*L orMa = 0.6(469.8#”+(170.1L)#”) + (W*L#*27) = 281.88#”+102.06L+27W*L for uplift
Check brackets based on the maximum allowable length of 16’ (4’+8’+4’) with 25 psf load.
Ma = 469.8#”+170.1*16+27*25*16 = 13,991#” orMa = 469.8#”+170.1*16+20.25(25+25)*16 = 19,391#”Ma = 281.88#”+102.06*16 -27*25*16 = -8,885#”
Attachments to wood, concrete or steel are adequate for the maximum canopy size and 25 psfwind (ASD level) or snow loads
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For GAB48:Glass width, B = 48”
Bracket weight: Db = [0.5”*{(6+2)/2*24”+24*6}]*0.28#/ci +2*1.3# = 36.2#For 1/2” laminated glass (1/4”+.05”+1/4”) Dg = 2*2.9+0.5 = 6.3 psf
L = glass length (ft)MDf = 36.2#*20”+(6.3psf*4’*L/2)*24” = 724#”+(302.4L)#”Snow load or Wind (ASD level) loadSb = (Spsf*4’*L/2) = 2S*L plf Wb = (Wpsf*4’*L/2) = 2W*L plf MbS = 2S*L plf*24” = 48SL
MbW = 2W*L plf*24” = 48SL
For service loads (Steel or concrete)Ms = 1.2*(724#”+(302.4L)#”) + 1.6(S*L#*48) = 868.8#”+362.88L+76.8SL orMs = 1.2*(724#”+(302.4L)#”) + 1.6(W*L#*48) = 868.8#”+362.88L+76.8WL orMs = 1.2*(724#”+(302.4L)#”) +0.75[(S+W)L#*48]=868.8#”+362.88L+36(S+W)L
Ms = 0.9*(724#”+(302.4L)#”) + 1.6(W*L#*48) = 651.6#”+272.16L+76.8W*L uplift
Based on glass strength the maximum bracket spacing, e = 8’-0” for 1/2” glass and 25 psf wind(ASD level) or snow load. The maximum cantilever length, d = 4’-0”
Check brackets based on the maximum allowable length of 16’ (4’+8’+4’) with 25 psf load.Ms = 868.8#”+362.88*16+76.8*25*16 = 37,395#” orMs = 868.8#”+362.88*16+36(25+25)*16 = 35,475#”Ms = 651.6#”+272.16*16 - 76.8*25*16 = -25,714#” uplift
For allowable loads (wood)
Ma = (724#”+(302.4L)#”) + (S*L#*48”) = 724#”+302.4L+48S*L orMa = (724#”+(302.4L)#”) + (W*L#*48”) = 724#”+302.4L+48W*L orMa = (724#”+(302.4L)#”) + 0.75[(S+W)*L#*48] = 724#”+302.4L+36(S+W)*L orMa = 0.6(724#”+(302.4L)#”) + (W*L#*48) = 434.4#”+181.44L+48W*L for uplift
Check brackets based on the maximum allowable length of 16’ (4’+8’+4’) with 25 psf load.
Ma = 724#”+302.4*16+48*25*16 = 24,762#” orMa = 724#”+302.4*16+36 (25+25)*16 = 34,362#” > 21,008#”Ma = 434.4#”+181.44*16 -48*25*16 = -15,863#”
Lwood # 21,008/34,362*16 = 9.78’ = 9’-9”For attachment to wood maximum length L = 9’-9”
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GLASS STRENGTHGlass is fully tempered 2 layer laminated safety glass conforming to the specifications of
ANSI Z97.1, ASTM C 1048-97b and CPSC 16 CFR 1201. The minimum Modulus of Rupturefor the glass Fr is 24,000 psi. Glass not used in guardrails may be designed for a safety factor of
2.5 in accordance with ASTM E1300-00.Adjustment for laminated glass (both layers equal) = 1.7 single layer strengthAllowable glass bending stress: 24,000/2.5 = 9,600 psi. – Tension stressAllowable bearing stress = 24,000 psi/2.5 = 9,600 psi.
Determine effective thickness of the laminated glass for stresses and deflections based on ASTM
E1300-09a appendix X11.h1 = h2 = 0.219”hv = 0.06”a = 48”hs = 0.5(h1+h2)+hv = 0.5(0.219*2)+0.06 = 0.279”hs;1 = hs;2 = (hsh1)/(h1+h2) = (0.279*0.219)/(2*0.219) = 0.1395
Is = h1h2s;2+ h2h2s;1= 2*(0.219*0.279”2)= 0.034# = 1/[1+9.6(EIshv)/(Gh2sa2)]
For heat and size use interlayer shear modulus of 80 psi (T # 120 F˚)# = 1/[1+9.6(10,400,000*0.034*0.06)/(80*0.2792*482)] = 0.0658
effective thickness for deflection:hef;w = (h13+ h32+ 12#Is)1/3 = (0.2193+ 0.2193+ 12$0.0658$0.034)1/3 = 0.363 # 0.498
effective thickness for glass stress:
h1;ef;% = [hef;w3/(h+2# hs;1)]1/2 = [0.3633/(0.219+2$0.0658$0.1395)]1/2 = 0.449 # 0.498
Ie = hef;w3 = 0.3633 = 0.0478 in4/ft
Se = 2 h1;ef;% 2 = 2*0.4492 = 0.403 in3/ft
Bending strength of glass for the given thickness: S = 12”* (t)2 = 2* (t)2 in3/ft 6
Allowable bending moment on glass is: Mas = 9,600 psi*0.403 in3/ft = 3,868.8”#/ft short duration loads Malt = 0.43*9,600 psi*0.403 in3/ft = 1,664”#/ft = 138.6’#/ft 1 month loads
M 0 31*9 600 i*0 403 i 3/ft 1 199”#/ft 99 9’#/ft t l d
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Mc = U*d2/2 at support axis Mc = P*d
Dead load equivalent load = 0.3978/0.169*6.3 = 14.8For a design load of W = 25 psf (live or wind (ASD level)) or P = 50 lb load
U = 25+14.8 = 39.8psf Based on assumed b/e # 0.33 e = [(3,868.8”#/12)*8/39.8psf]1/2 = 8’ = 96”
e = 3,868.8”#*4/50 = 305.5” = 25.46’ concentrated loads won’t control d = [(3,868.8”#/12)*2/39.8psf]1/2 = 4’ = 48” Cantilevered length d = 3,868.8”#/50 = 76” concentrated loads won’t control
The allowable uniform load may be calculated using: Us = [(322.4/Ce)/e2] or Us = [(322.4/(4Ce))/d2]
or for long term loads:
Ult = [(138.6/Ce)/e2] or Ult = [(138.6/(4Ce))/d2]
or for permanent loads:
Uper = [(99.9/Ce)/e2] or Uper = [(99.9/(4Ce))/d2]
For multiple types of load:
Us/Mas + Ult/Malt + Uper/Maper # 1.0
NOTE:
Visual sagging of the glass will occur at the design loads.For longer glass spans sagging from dead loads may be visible.
Glass deflections assuming minimal end overhangs-For dead loads, L in inches' = (1-(2)*5*7psf/12*L4 = (1-0.222)*5*7psf/12*L4 = 1.453*10-8*L4
384 Et3 384*10,400,000*0.3633
For 72” bracket spacing:
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Allowable Uniform Load (U) in psf on 9/16” tempered laminated glass based on glass strength:
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Allowable uniform load (U) in psf with awning length in feet based on bracket strength:
GAB24 Bracket – 24” glass widthUniform Load Support
Awning length Steel Concrete Wood
4 2141.5 520.4 437.6
6 1427.7 346.9 291.8
8 1070.8 260.2 218.8
10 856.6 208.2 175.1
12 713.8 173.5 145.916 535.4 130.1 109.4
GAB36 Bracket – 36” glass width
Uniform Load Support
Awning length Steel Concrete Wood
4 951.8 231.3 130.1
6 634.5 154.2 86.88 475.9 115.6 65.1
10 380.7 92.5 52.1
12 317.3 77.1 43.4
16 237.9 57.8 32.5
GAB48 Bracket – 48” glass width
Uniform Load SupportAwning length Steel Concrete Wood
4 535.4 130.1 109.4
6 356.9 86.8 72.9
8 267.7 65.1 54.7
10 214.2 52.1 43.8
12 178.5 43.4 36.5
16 133.8 32.5 27.3
Total loads are based on controlling load combination (use D = 14.8 psf):D+S or Sallowable = U-14.8D+W or Wallowable = U-14.8
D 0 75(S W) S W 1 333U 19 3
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RB50F
fittings are connected together with1/4” stainless steel threaded rods.
Vs = 0.65*40.5 ksi*0.049 in2/1.6 = 806#Ts = 0.75*67.5ksi*0.0318 in2/1.6 = 1,006#
Torsion strength of swivel when clamped: = 0.65*1,006#*13/16 = 531”#
Moment strength of swivel:Bending in rod to fixed fitting:rod diameter = 3/8”, A = 0.11 in2
Z = 0.3753/6 = 0.0088 in3
Fb = 65 ksi (longitudinal compression)
Mn = 65 ksi*0.0088 in3 = 572#”
Service loads on swivel:Allowable load will be controlled by the bending strength of the connection rod:
Ms = 0.9Mn/1.6 = (0.9*572#”/1.6) = 322#”
For lateral loading, M = V*2.25”V = 322#”/2.25 = 143# per swivel
For normal loads, M = H*0.75”
H = 322#”/0.75” = 429#
Check strength of fixed bracket to support ( 1/4” threaded rod)Ms = R*Ts = 13/16”*1,006# = 1,584#”
For lateral loading, M = V*2.25”
V = 1,584#”/2.25 = 704# per swivel (limited to 143# from connector rod strength)
For normal loads, M = H*2.5”H = 1,584#”/2.5” = 633.6# (limited to 429# by connector rod strength.
Maximum vertical load per fitting = 429#
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