Loading...
HomeMy WebLinkAboutFile Documents.909 E Hopkins Ave.0056-2021-BRES (28) Edward C.Robison, P.E. 16 OCT 2019 C.R.Laurence Co.,Inc. 2503 East Vernon Los Angeles,CA 90058 SUBJ: CRL SRS STANDOFF RAILING SYSTEM GLASS BALUSTRADE GUARDS The SRS Standoff Railing System is a guardrail system that utilizes point supported glass balustrades. When constructed in accordance with the attached details and installation guidelines the guardrail can designed to safely support the following loading conditions: 200 pound point load on top rail,vertical or horizontal or 50 plf load on top rail,vertical or horizontal or 25 psf uniform load on glass panel horizontal or 50 lb conc load on 1 sf or Wind load -As listed with respect to glass size or determined by FEA modeling Typical glass thickness: 3/4" monolithic or 13/16" laminated minimum thickness. For exterior installations wind loads and glass stress must be calculated by a qualified licensed engineer. For single family residential construction only the 200#concentrated top rail load,50#concentrated load and wind load (exterior) are applicable (non-concurrent). The SRS is to be used with tempered glass only,laminated or monolithic. Laminated glass must be made with Kuraray SentryGlas+ interlayer or an equivalent ionoplast interlayer. Glass light stresses were evaluated using finite element analysis (FEA) with SCIA Engineer 18.1 in order to derive rules for designing a code compliant system. Generally,a qualified licensed engineer must evaluate a specific installation for code compliance using a FEA model or other recognized method. All results given in this paper are based on the assumption that the top rail has inadequate strength and stiffness to cause significant load sharing between the glass lights except as specifically stated herein. Added support from stronger and stiffer top rails that anchor to posts or walls independent of the glass balustrade may significantly reduce the glass stresses and deflections. When designing a glass balustrade with the additional support a FEA model should be used which accounts for the proposed specific conditions. The recommendations herein are intended to assist a qualified licensed engineer in developing a code compliant guard that meets the applicable requirements of the 2009,2012,2015 and 2018 International Building Code and state codes adopted from the IBC codes. This paper is not intended to demonstrate the code compliance of an installation but is to only be utilized by the qualified 10012 Creviston DR NW 253-858-0855 Gig Harbor,WA 98335 fax 253-858-085��^���V/�(� �A email: elrobison@narrows.co ,.� 04/01/2021 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 2 of 31 licensed engineer in charge of the glass balustrade guard in analyzing the glass stresses and anchorage. This paper only evaluated 2 and 3 standoff pairs per light. Additional standoffs may be used and will decrease the glass stress. If additional standoffs are proposed a FEA model should be used to determine the glass stresses,deflections and standoff reactions. Notes on developing an effective FEA model: When developing a FEA model the glass stresses are very sensitive to small changes in the boundary conditions and how the supports are represented. It should be assumed that the clamping at the standoff fittings when using the fittings in this paper will provide reaction points at the horizontal centerline of the edges of the holes. No significant moment resistance will occur at the standoffs so that the reactions should be modeled as surface bearing only. Moment resistance is provided by the force couple developed between the two standoffs in a pair. These recommendations are based on creating a FEA model that is consistent with the results of physical testing by CRL The standoffs must always be used in vertical pairs. Vertical loads should be assumed as acting on only a single standoff in each pair,and only on two standoffs when more than 2 pairs are used. Table of Contents Signature Page 3 Glass Strength 4 - 5 Glass Panel Loads 5 Allowable Wind Loads 6 - 13 Guard Rail Applications 14 - 15 Glass Standoffs 16— 17 Custom Standoff lengths 18 RSOB20 Fitting 19 Grab Rails and Cap rails 20 FEA Result Tables 1/2" glass 21 - 31 Edward Robison,P.E. Edward C.Robison,P.E. 10012 Creviston DR NW 25 a Gig Harbor,WA 98335 fax 2':A L -.; VED email: elrobison @ na 0 4 .cOM/2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System—SRS 10/16/2019 Page 3 of 31 Si• .(/ ess \d/ti*fi r • /1 •••••••••• ••••, 1o\FIC A TF'% pQ0 C. Rq k O � ''°�Pp'c:' ti Pi RDe<S' ` RoA <49 OC E N 42123 0 co S� `p : -1/; :t • 63683 EDWARD C. ©o 54027 0• UP , "/ ;� i ,, _ . '4414-1 41 NA q OP 0�CF CA\ O — ONA EXP o 1/2020 EXP 02/28/2021 (,...--i-.9 C. /-"Fi5"-• \\\ F Mgf, i LICENSED 2 OS.. �t<. co; P` .r•� ,rl' <Sj O PROFESSIONAL k. ••• •• Z = :0 `.0'•. * ENGINEER * .;EDWARD C•:GI = L I •:.rr ><Z; No. 11 576-5 u : ROBISON • m 7- 1.," y'tl1�Iehe ' THIS WORK WAS PREPARED BY t UNDER MY SUPERVISION OF �•y'S•t �iSi�NALk k\\ /" Professional Certification.i hereby certify that these /30/2020 EXP 11/30/2020 documents were prepared or approved bymc,and that I am a duly licensed professional engineer under the laws of the State of Maryland, Signature Expiration Date of the License License No.52500,Expiration Date:04/092020" \\ SfA LURAL'1) Z'z 2/31/201.LLl• ��9000 N I E>eP' / •„ 1 g pNo.49757 :�•,..i� • : /f •: iv! Z, t'rl bt>, G/STEce c� ..1 QQ ; f l s '•// •'...•' *•ar' /7" SSA 5����' jti 4••;y �_ s �, 088030 _ OFMISS\,;,/' 4�N0.17546 O EXP 06/30/2020 EXP 03/31/2021 ,QED PROF •,,•......__, �..�‘ ��,,....... �`V F /���CN �� .C'p�E•Y.F•:64-`11 1.1.. ....... RUCTU/� �N6INEFR t1 t.- \y i 5' ��S� •'• �... �� 18195PE 11 eiati I f o` ii ���/' #� •1 O •••,G_ IrCliel 4'<'...... EDWARD O. ROBISON; ; U/• No.10738527-2203 .rn EDWARD C.ROBISON I I • U:EDWARD C.ROBISON:m F 44' N9°,S • ��1��� Il��•,, 01(3,5j.. 100688 :•��� . 0 C, 6 1 \50 _tv 4109u % II Ilo�cc</r, e:O..•'�a�‘ "/ , �- ,� '�RD R0� z �� ��i 1eSiONALENG.- �` EXP 1 2/31/2020 ...,•" FIRM#F-12044 S'TgT".•"�-.P`.)`.•' EXP 09/30/21 EXP 12/31/2019 ,E OF . 1'4'V..-r0T H OF D ess &) tonal v� 1' � C. R o\ 40 0 ,.-�i�i 1 W o� Qt ay4atd 0. 064 60.. - , , 'r. �`S' ' ' 14 ,�d0 16531 °EDWARD C. ROBISON> c� '•• �i^ Lic No.059203 %�- 4 . •• #-.r ' 91‘ , A , E Date O.�IP4'GISTE065" 4/ONAL " SIONAL PI/YOMING Edward C. Robison,P.E. 10012 Creviston DR NW 25 .:_ : ' : . Gig Harbor,WA 98335 fax 2'I J L.: t :- ;�VED email: elrobison@na 0 4;. /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 4 of 31 GLASS BALUSTRADE GUARD RAIL GLASS STRENGTH All glass is fully tempered glass conforming to the specifications of ANSI Z97.1, ASTM C 1048-97b and CPSC 16 CFR 1201. For the 1/2" glass the typical Modulus of Rupture,Fr is 24,000 psi. The applicable safety factor against glass rupture is 4.0 in accordance with IBC 2407.1.1 Allowable glass bending stress: 24,000/4 = 6,000 psi.—Tension stress calculated for live loads. Bending strength of glass for the given thickness: S = 12"* (t)2 = 2* (t)2 in3/ft 6 Use the minimum glass thickness for stress calculations: Figure 1 For 1/2" glass,train=0.469" ; Weight= 6.5 psf S = 2*(0.469)2 =0.44 in3/ft Nr Mauve= 6,000psi*0.44 in3/ft= 2,640"#/ft= 220'# For 5/8" glass,tmin=0.595" ; Weight= 8.1 psf S = 2*(0.595)2 =0.708 in3/ft Mauve= 6,000psi*0.708 in3/ft=4,248"#/ft= 354'# For 3/4" glass,train=0.719" ; Weight= 9.8 psf S = 2*(0.719)2 = 1.034 in3/ft =t Mauve= 6,000psi*1.034 in3/ft= 6,204"#/ft= 517'# The allowable moments are based on the minimum lass / g thickness allowed for the nominal thickness. The section w w properties and allowable moments may be calculated based I �I on the actual glass thickness supplied. Laminated glass shall be evaluated based on the effective thickness determined in accordance with ASTM E1300-12a or the DuPont online laminated glass calculator. For wind loading, allowable glass stress is 10,600psi. Allowable wind load pressures vary depending on glass thickness,width,height and standoff spacing.Allowable wind loads are according to the tables on the following pages. Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:_ ; ' : . Gig Harbor,WA 98335 fax 2': L : VELA email: elrobison@na 0 4%.c 1/2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 5 of 31 Laminated Glass Sizes Effective glass thickness is determined according to ASTM E1300.The assumed glass interlayer is SGP at high temperatures (130° F)based on exterior application. 9/16" Glass: Laminated Glass Effective Thickness Variable Description Hl&H2 Glass pane thicknesses hl h2 hv E Hv Interlayer thickness 0.2191 0.2191 0.061 10400000( 1640 E Young's Modulus hs hs;l hs;2 IS g Shear Modulus Hs .5(hl+h2)+hv 0.2791 0.13951 0.13951 0.008523591 Hs;1 hshl/(hl+h2) a r hef;w h1;ef;Q h2;ef;a Hs;1 hsh2/(hz+h2) I2 361 0.764165011 0.4628681291 0.479007721 0.47900772 a5 Minimhl(hsum +Pane W Minimum Pane Width r 1/(1+9.6(Eishv/(G(ahs)')) 13/16" Glass: hef;W "1((hl)'+(h2)'+12rls) h1;ef;a I((hefw)'/(h1+21-h5;2)) h2;ef;a 4((hefw)'/(h2+21115;1)) Laminated Glass Effective Thickness h1 h2 hv E g 0.355 0.355 0.06 104000001 16401 hs hs;1 hs;2 Is 0.4151 0.20751 0.207510.0305699381 a r hef;w h1;ef;Q h2;ef;Q 3610.6665462431 0.69381841110.727180009 0.727180009 The effective thickness of other laminated glass configurations may be evaluated using this procedure. The standoffs may be used with thicker glass than considered in this report to provide greater load resistance. Edward C.Robison,P.E. 10012 Creviston DR NW 25 .;_ ; ' : . Gig Harbor,WA 98335 fax 2'1ALiPM- 1.VED email: elrobison @ na 0 4%.0 /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 6 of 31 WIND LOADING ON GLASS Allowable wind loads are based on the wind load that causes the maximum allowable stress in the glass. Allowable wind load tables do not account for standoff anchorage strength which must be considered separately. These tables are for wind load only and the configuration might not comply for a guard application. Allowable Wind Load(psf),Two Standoff Pairs At 4" Spacing, 1/2" Monolithic Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 38.5 30.4 24.9 21.0 42 27.3 21.7 17.8 15.0 50 18.6 14.0 12.3 10.4 60 12.5 10.0 8.3 7.1 Allowable Wind Load(psf),Two Standoff Pairs At 4" Spacing,5/8" Monolithic Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 62.0 49.0 40.1 33.7 42 43.9 34.9 28.7 24.2 50 30.0 22.5 19.7 16.7 60 20.2 16.2 13.4 11.4 Allowable Wind Load(psf),Two Standoff Pairs At 4" Spacing, 3/4"Monolithic Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 90.6 71.5 58.6 49.3 42 64.2 51.0 41.9 35.4 50 43.8 32.9 28.8 24.4 60 29.5 23.6 19.5 16.6 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:_ : ' : . Gig Harbor,WA98335 fax2':AL . -.; VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 7 of 31 Laminated glass should only be made with the SentryGlas+ or equivalent tonoplast interlayer. Allowable Wind Load(psf),Two Standoff Pairs At 4" Spacing,9/16"Laminated Glass Glass Height(in) lass Width (in) .. M 36 48 60 72 36 40.2 31.8 26.0 21.9 42 28.5 22.6 18.6 15.7 50 19.4 14.6 12.8 10.8 60 13.1 10.5 8.7 7.4 Allowable Wind Load (psf),Two Standoff Pairs At 4" Spacing, 13/16"Laminated Glass Glass Height( Glass Width (in) 36 48 60 72 36 92.6 73.1 59.9 50.4 42 65.6 52.1 42.8 36.2 50 44.7 33.6 29.4 24.9 60 30.2 24.1 20.0 17.0 For wind loads under 10 psf the configuration may only be used for an interior application only. Edward C.Robison,P.E. 10012 Creviston DR NW 25 : . VEDGig Harbor,WA 98335 fax 2':A L i - 1 email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 8 of 31 Allowable Wind Load(psf),Three Standoff Pairs At 4" Spacing, 1/2" Monolithic Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 52.2 43.6 37.0 31.5 42 36.8 30.4 26.0 22.4 50 23.9 20.1 17.7 15.3 60 15.9 13.4 11.5 9.9 Allowable Wind Load(psf),Three Standoff Pairs At 4" Spacing,5/8" Monolithic Glass lass Height in Glass Width (in) 36 48 60 72 36 84.0 70.1 59.6 50.7 42 59.2 49.0 41.8 36.0 50 38.5 32.3 28.5 24.6 60 25.6 21.6 18.5 15.9 Allowable Wind Load (psf),Three Standoff Pairs At 4" Spacing, 3/4" Monolithic Glass Glass Height(� Glass Width (in) 36 48 60 72 36 122.7 102.4 87.0 74.0 42 86.4 71.5 61.0 52.6 50 56.3 47.2 41.6 35.9 60 37.4 31.5 27.0 23.3 For wind loads under 10 psf the configuration may only be used for an interior application only. Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- ; ' : . Gig Harbor,WA98335 fax2':AL . -.; VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 9 of 31 Allowable Wind Load(psf),Three Standoff Pairs At 4" Spacing,9/16" Laminated Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 54.4 45.4 38.6 32.8 42 38.4 31.7 27.1 23.4 50 25.0 20.9 18.5 16.0 60 16.6 14.0 12.0 10.3 Allowable Wind Load(psf),Three Standoff Pairs At 4" Spacing, 13/16" Laminated Glass lass Height in I I 1 I I I I Glass Width (in) 36 48 60 72 36 125.4 104.7 88.9 75.6 42 88.4 73.1 62.4 53.8 50 57.5 48.2 42.5 36.8 60 38.3 32.2 27.6 23.8 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- ; ' : . Gig Harbor,WA98335 fax2':AL . -.; VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 10 of 31 Allowable Wind Load(psf),Two Standoff Pairs At 6" Spacing, 1/2"Monolithic Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 51.2 41.3 31.5 27.8 42 35.7 28.0 23.2 19.7 50 23.3 18.3 15.8 13.4 60 15.4 12.6 10.6 9.1 i Allowable Wind Load(psf),Two Standoff Pairs At 6" Spacing,5/8"Monolithic Glass lass Height in I r I Glass Width (in) 36 48 60 72 36 82.4 66.4 50.6 44.7 42 57.5 45.1 37.3 31.7 50 37.6 29.5 25.4 21.6 60 24.9 20.4 17.1 14.6 Allowable Wind Load (psf),Two Standoff Pairs At 6" Spacing, 3/4" Monolithic Glass Glass Height(� M MGlass Width (in) 36 48 60 72 ■36 120.3 97.0 73.9 65.3 42 83.9 65.9 54.5 46.2 50 54.9 43.1 37.1 31.6 60 36.3 29.7 24.9 21.3 For wind loads under 10 psf the configuration may only be used for an interior application only. Edward C.Robison,P.E. 10012 Creviston DR NW 25 i- VED Gig Harbor,WA 98335 fax 2'i Al L i email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 11 of 31 Allowable Wind Load(psf),Two Standoff Pairs At 6" Spacing,9/16"Laminated Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 53.4 43.1 32.8 29.0 42 37.3 29.2 24.2 20.5 50 24.4 19.1 16.4 14.0 60 16.1 13.2 11.1 9.5 I Allowable Wind Load(psf),Two Standoff Pairs At 6" Spacing, 13/16" Laminated Glass lass Height in I r I I Glass WidI 11 th (in) 36 48 60 72 36 123.0 99.2 75.6 66.8 42 85.8 67.4 5.5.7 47.3 50 56.1 44.1 37.9 32.3 60 37.1 30.4 25.5 21.8 For wind loads under 10 psf the configuration may only be used for an interior application only. Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- ; ' : . Gig Harbor,WA98335 fax2':AL . -.; VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System -SRS 10/16/2019 Page 12 of 31 Allowable Wind Load(psf),Three Standoff Pairs At 6" Spacing, 1/2" Monolithic Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 64.9 55.1 47.7 41.5 42 44.4 38.1 32.8 27.1 50 29.4 24.5 21.4 18.9 60 18.0 16.2 14.2 12.5 Allowable Wind Load(psf),Three Standoff Pairs At 6" Spacing,5/8" Monolithic Glass lass Height in I r I I Glass Width (in) 36 48 60 72 36 104.5 88.7 76.7 66.7 42 71.5 61.3 52.8 43.6 50 47.4 39.5 34.5 30.4 60 29.0 26.1 22.8 20.1 Allowable Wind Load(psf),Three Standoff Pairs At 6" Spacing, 3/4" Monolithic Glass Glass Height(� Glass Width (in) 36 48 60 72 36 152.6 129.6 112.0 97.5 42 104.5 89.5 77.1 63.7 50 69.1 57.6 50.4 44.4 60 42.3 38.1 33.3 29.4 Edward C.Robison,P.E. 10012 Creviston DR NW 25: _ :.!:. GigHarbor,WA98335 fax2':�L : - 1 VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 13 of 31 Allowable Wind Load(psf),Three Standoff Pairs At 6" Spacing,9/16" Laminated Glass Glass Height(in) Glass Width (in) 36 48 60 72 36 67.7 57.5 49.7 43.3 42 46.4 39.7 34.2 28.3 50 30.7 25.6 22.4 19.7 60 18.8 16.9 14.8 13.1 Allowable Wind Load(psf),Three Standoff Pairs At 6" Spacing,3/4" Laminated Glass lass Height in Glass Width (i 36 48 60 72 36 156.0 132.4 114.5 99.6 42 106.8 91.5 78.8 65.2 50 70.7 58.9 51.5 45.4 60 43.3 38.9 34.0 30.1 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- ; ' : . Gig Harbor,WA98335 fax2':AL . -.; VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 14 of 31 GUARD RAIL APPLICATIONS When used as a guard rail,the imposed live loading will generally control the glass design.For commercial applications,the guard rail is subject to a 50p1f uniform top rail load or a 200# concentrated load. Most residential applications will only be subject to the 200#concentrated. In most guard rail applications, 13/16" laminated or 3/4" monolithic glass is required. Maximum glass height is 50" and a continuous top rail must be used. Additionally,in most cases the unsupported corner of the end lite will require bracing. Otherwise,the specific installation must be analyzed to confirm it is capable of holding the 200#concentrated load. Minimum lateral stiffness of top rail (Ely)is 747,4001bs-in2. The below tables show allowable glass heights (measured from bottom of glass to top of glass),for different glass widths and stand off conditions. Maximum heights in order to resist 50p1f load along top. 3/4" Monolithic or 13/16" Laminated glass, 2 Standoff Pairs At 4" Spacing Glass Width (in) 36 48 60 Allowable Height(in) 50 42 42 36 3/4" Monolithic or 13/16" Laminated glass,3 Standoff Pairs At 4" Spacing Glass Width (in) 36 Allowable Height(in) 50 50 42 36 3/4"Monolithic or 13/16" Laminated glass,2 Standoff Pairs At 6" Spacing lass Width (in) Allowable Height(in) 50 42 42 39 3/4" Monolithic or 13/16" Laminated glass,3 Standoff Pairs At 6" Spacing Glass Width (in) 36 Allowable Height(in) 50 50 42 36 Edward C.Robison,P.E. 10012 Creviston DR NW 25 Gig Harbor,WA98335 fax 2':;L . -.; VED email: elrobison @ na 0 4 .cOM/2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 15 of 31 Allowable heights to resist 200#concentrated load: 3/4"Monolithic or 13/16" Laminated glass,2 Standoff Pairs At 4" Spacing Glass Width (in) Allowable Height(in) N/A N/A N/A N/A 3/4" Monolithic or 13/16" Laminated glass,3 Standoff Pairs At 4" Spacing Glass Width (in) Allowable Height(in) 36 42 36 36 3/4" Monolithic or 13/16" Laminated glass,2 Standoff Pairs At 6" Spacing Glass Width (in) 36 Allowable Height(in) 36 36 36 N/A 3/4" Monolithic or 13/16" Laminated glass,3 Standoff Pairs At 6" Spacing Glass Width (in) 3 Allowable Height(in) 42 42 42 42 Use of a stiffer and stronger top rail will allow the glass height to be increased to the same as the 50 plf tables for lights L<_60 inches for a top rail with EI exceeding 2.2x106 lb-in2. E= 25x106 for stainless steel and 10x106 for aluminum Example top rails- For stainless steel Ix 0.094 in4 (weakest axis) GR16 and larger GRS 15 and larger SRF15 and larger L10 or heavier U cap rail For aluminum IX>_0.22 in4 (weakest axis) GR19 and larger custom U cap rail with required stiffness For brass IX>_0.18 in4 (weakest axis) GR25 or GR257 and larger GRS20 and larger SRF20 and larger custom U cap rail with required stiffness Edward C.Robison,P.E. 10012 Creviston DR NW 25 Gig Harbor,WA98335 fax 2': ;L . -.; VED email: elrobison @ na 0 4 .cOM/2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 16 of 31 GLASS STANDOFFS To determine reactions on 3/8" — 4 mm 10, m the standoffs: (10 mm) h� Reactions are calculated ' ___ fStandoff using summation of forces011 and summation of 2'(51 mm) 1 moments: 2"(51 mmi Long V— D+L 3-8"-16 Nbunting Stud For Use With — (Included( 1/2`or 314'Glass Neop ene where D = glass dead load (12 or 19 mm) Black basket plus cap rail or other attachments to the glass. L= greater of 200#or 50p1f* B Vertical load share per standoff: VS=D/2 standoffs Assumes vertical load is supported on any 2 standoffs to allow for construction tolerances,glass expansion and contraction and other factors that may cause uneven vertical loading on the standoffs Moment on standoffs from vertical force: My=Vs*k where k=distance from centerline of glass to face of support attachment,typically 2" for RSOB2134 standard fitting. For horizontal loading,moment about upper standoffs: ML= 50p1f*B*h or 200#*h MW =w*B*h2*0.55 W= w*B*h MT = greater of(ML or MW) +M\ Glass standoffs resist loading by forming a couple (tension and compression reactions) Two pairs of standoffs per panel Calculate RI by EM about R„ EM=MT+(a-c)* R1 =0 R1 =MT/(a-c) Typically a-c =4" minimum Load share to individual standoff: Rs1 =Ri/n where n=number of standoff pairs,2 or 3. R„=Ri+F where F= either wind force or live load depending on which produced the greatest moment. RS„ =R„/n Edward C.Robison,P.E. 10012 Creviston DR NW 25, : -8-0855gVED Gig Harbor,WA 98335 fax 2':4 8-085 email: elrobison@na 04%.c 1/2021 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 17 of 31 Standoff anchors—3/8" stainless steel threaded rod to standoff and 3/8" rod to steel support. Tensile area of 3/8" threaded rod (UNC) =0.0775 in2 Rod strength= (0.6*75ksi) * 0.0775 in2= 3,487# Check thread strength into standoff—minimum thread embed= 3/8" Internal thread stripping area=0.828 in2 for 3/8— 16 threads Allowable load on threads = 0.58*As„*t*Ft„/3 =0.58*0.828*(3/8)*45ksi/3 = 2,700# Allowable shear strength=0.3*75 ksi*0.0775 in2= 1,744# Standoff welded to plate— 1/8" fillet weld: (welded option) Ta=0.9*1/8"*n*2"*40 ksi/1.6 = 17.7 k Va=0.3*17.7 k= 5.3 k For welded standoff case the button attachment strength limits the loading. Determine tension and shear on mounting stud: From forces: Vertical loads will increase tension force in mounting stud: T=TM+V*2"/1" Check Interaction of shear and tension. Check combined tension and shear on anchors: H# + V# =0.44 < 1.2 Ok 2,700# 1,744 Example for a glass light,3/4" x 52" tall x 72" long with 25 psf wind loading: D = 9.8*(6'*4.333')/2 = 127#< 1,744# Tension component of reaction W= 25psf*3.667'*6'/2 = 275#to standoff M= (25psf*3.667'2*6'/2)*0.55 = 555'# R1 = (555*12)/(4") = 1,664# Ru= 1,664+275 = 1,939# T= 1,939+127*2"/1" = 2,193< 2,700 Combined tension and shear: 2,193# + 127# =0.885 < 1.2 Ok 2,700# 1,744 STANDOFF STRENGTH IS ADEQUATE FOR ALL ACCEPTABLE LIGHT SIZES. Edward C.Robison,P.E. 10012 Creviston DR NW PI 25 : Gig Harbor,WA 98335 fax 2':4 L : - 1 VED email: elrobison @ na 0 4 .cOM/2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 18 of 31 CUSTOM STANDOFF SIZE: The standoff design allows easy customization by changing the length of the standoff body so as to increase or decrease the standoff distance. The moment and tension on the standoff is calculated the same as for the standard standoff: T=TM+V*(J+t/2)/1" where: Tm and V are as previously calculated based on light size and loading; J = standoff body length t= glass thickness based on the calculated T and V the standoff is checked from: T# + V# < 1.2 Ok 2,700# 1,744 and T<_ 2,700# For most cases V<_0.2*1,744#= 348.8# so the combined check may be skipped. Example: Determine the maximum allowable standoff length for the glass light checked on previous page: Example for a glass light,3/4" x 52" tall x 72" long with 25 psf wind loading: D = 9.8*(7'*4.333')/2 = 149#< 1,744# Tension component of reaction W= 25psf*3.667'*6'/2 = 275#to standoff M = (25psf*3.667'2*6'/2)*0.55 = 555'# Ri = (555*12)/(4") = 1,665# Ru= 1,665+275 = 1,940#< 2,700 T= 1,940+127*(J+0.75/2)/1" <_ 2,700# J=(2,700-1,940)*1"/(127#)-0.375" = 5.61" For standoff bodies less than 5.61" the light sizes and wind loads are the same as for the standard standoff. For standoffs longer than 5.61"the light size and wind load must be checked for the standoff strength. Edward C.Robison,P.E. 10012 Creviston DR NW 25 .: Gig Harbor,WA98335 fax2':�� :OM-.; VED email: elrobison @ na 0 4 .cOM/2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 19 of 31 RSOB20 STANDOFF FITTING 8 x 4 x 38 1R'or 3,4 Bracket strength 203 x 103 x 9581011 Thick Stainless Moe 19mml Stainlessihsck Clear Steel Plate P Tempered Glass Bending in plate: l-3'4 7 3+$19 5 mml Bracket bending strength: (44 x 51 mm ��* 2in3 (102 mmls Dd for Steel Z=4 (0.375) /4=0.1406 • 38 rille(9 5 mm) Support (203 mm) Bons (by Others) t Mn=0.85*30 ksi* 0.1406 in3 = 3,585"# 318 MS =0Mn/1.6 = 3,585/1.6= 2,241"# (51 mm) (955mm) 1 ya, (44 mm) Allowable moment on glass standoff: (203mm) Wood tIoh 1.3/4'x 2' 1/2'or 3/4' M = 2*2,241"#=4> W 482"# 144 x S51 nmm)kss 4 TA krc1eamr Or allowable tension Steel tempered Gass Support T= 2,241*4.93/3.5" = 3,157# (byOthe1s) IN ? 8x4'x38' am 8 Bracket bending will not limit standoff 4'1102 mm) (51 mni) (203 x Thick Stainless rn) ��(203 mm) loads below the values based on the stud Steel Plate .�—� 3+8' 3/8' strength. (95 mm) 1_34 (9 5 mm) (44 mm) Steel Applrcanon Bracket reactions on anchors: Anchors form couple to resist moment on the guards. Determine anchor tension from E M about the bottom of the bracket: EMb=w*B*H2/2 +V*2.25"—n2T(7.5"+42/7.5) solving for T: T= (12"/ft*w*B*H2+2.25V)/(38.5"n) If V is dead load only: V= 9.8psf*B*H/2 substitute and simplify T= [12*w*B*H2+11.025B*H)]/(38.5"n) where n=number of brackets For typical maximum light size and load: 3/4" x 52" tall x 84" long with 25 psf wind loading T= [12*25*7*4.3332+11.025*7*4.333)1/(38.5") T= 344#/fastener Typical fastener: 1/2" x 3" lag screw to wood or 3/8" x 3" expansion bolt to concrete or 3/8"bolt to steel. Edward C.Robison,P.E. 10012 Creviston DR NW 25 •:_ ; ' : . Gig Harbor,WA 98335 fax 2':;L . -.; VED email: elrobison@na 04%.c 1/2021 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 20 of 31 Cap Rail/Grab Rail For guard installations—Fall protection required,a cap rail or grab rail is required. Cap rails and grab rails are the same as used in the GRS —Glass Rail System,refer to the GRS engineering report for the cap rails and grab rails. All cap rails intended for use with the GRS may be used with the SRS for the appropriate glass thickness. All grab rail brackets used with the GRS may be used with the SRS. The grab rail brackets' installation and strength is the same as for the GRS. Other Glass Thicknesses The Standoffs may be used with glass thicknesses other than those given in this report. When used with other glass thicknesses of monolithic or laminated glass the glass bending moment shall be evaluated using a finite element analysis model or other rational method. Edward C.Robison,P.E. 10012 Creviston DR NW 25 Gig Harbor,WA98335 fax 2':�L . - ; VED email: elrobison @ na 0 4 .cOM/2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 21 of 31 Appendix A FEA Model results for 1/2" monolithic glass,9/16 laminated results are similar. Based on these results when 1/2" or 9/16" glass is specified for a guard application engineering analysis must be performed that evaluates the glass stresses for the specific project conditions. 4"Vertical Standoff Spacing 50p1f Live Load Glass Stress,Assuming tmin=0.469" (1/2" Monolithic nominal),2 pairs as eig Glass Width (in) III 36 48 60 72 36 9926 12310 15540 18290 42 11810 15230 18390 21610 50 14050 18460 22190 26050 60 18110 22450 26960 31600 Glass Stress,Assuming tmin=0.469" (1/2" Monolithic nominal), 3 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 7937 9425 11020 12970 42 9492 11230 13510 15530 50 11540 14150 16510 18910 60 14660 17400 20220 23140 Glass Deflection,Assuming tinin=0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) Glass Width (indiW 36 48 60 72 36 0.913 1.12 ' 1.34 1.58 42 1.40 1.68 1.98 2.31 50 2.27 2.68 3.11 3.57 60 3.77 4.37 5.01 5.68 Edward C.Robison,P.E. 10012 Creviston DR NW 25 : . VEDGig Harbor,WA 98335 fax 2':A L : - 1 email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 22 of 31 Glass Deflection,Assuming 6;n=0.469" (1/2" Monolithic nominal), 3 pairs lass Height(in) Glass Width (in) 36 48 60 72 36 0.715 0.831 0.953 1.08 42 1.12 1.28 1.46 1.64 1 50 1.86 2.10 2.35 2.62 60 3.17 3.52 3.89 4.28 200#Live Load At Corner Glass Stress,Assuming tmin=0.469" (1/2" Monolithic nominal), 2 pairs Glass Height(i lass Width (inill 36 48 60 72 36 16010 15950 16280 16770 42 18570 18290 18530 18970 50 22000 21410 21500 21870 60 26330 25380 25230 25490 Glass Stress,Assuming train=0.469" (1/2" Monolithic nominal), 3 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 12070 11950 12400 13690 42 14380 14120 14440 14890 50 17280 16150 16280 16750 60 20000 18870 18770 19100 As shown the glass stress for the live loads will typically exceed 6,000 psi when 1/2" monolithic or 9/16" laminated glass is used. Thus for most installations where the glass must act as a guard rail the 1/2" and 9/16" glass options will not meet the safety or design factor of 4. Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- ; ' : . Gig Harbor,WA98335 fax 2':AL . -.; VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 23 of 31 Glass Deflection,Assuming 6;n=0.469" (1/2" Monolithic nominal),2 pairs lass Height(in) Glass Width (in) 36 48 60 72 36 1.40 1.38 1.42 1.48 ' 42 2.09 2.01 2.02 2.07 50 3.310 3.09 3.03 3.05 60 5.39 4.90 4.69 4.63 Glass Deflection,Assuming tm;n=0.469" (1/2" Monolithic nominal), 3 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 1.14 1.12 1.16 1.22 42 1.72 1.63 1.64 1.69 50 2.76 2.53 2.46 2.48 60 4.57 4.04 3.82 3.75 200#Live Load At Center Glass Stress,Assuming 6in.0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) IIIII Glass Width (in) 36 48 60 72 36 1 13770 12890 12480 12290 42 16370 15280 14750 14480 50 19840 19730 17780 17410 60 24170 22460 21590 21100 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:_ : ' : - GigHarbor,WA98335 fax2':�L : -.1 VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System - SRS 10/16/2019 Page 24 of 31 Glass Stress,Assuming tmin=0.469" (1/2" Monolithic nominal),3 pairs lass Height(in) Glass Width (in) 36 48 60 72 36 10780 9860 9540 9500 ' 42 12730 11650 11130 10910 50 16000 14370 13170 12900 60 19630 17520 16450 16010 Glass Deflection,Assuming tn,in=0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 1.25 1.18 1.16 1.19 42 1.90 1.74 1.68 1.68 50 3.06 2.74 2.59 2.52 60 5.07 4.44 4.11 3.93 Glass Deflection,Assuming tmin=0.469" (1/2" Monolithic nominal), 3 pairs Glass H e i gi I BliGlass Width (in) 36 48 60 72 36 0.976 0.871 0.823 0.803 42 1.52 1.33 1.23 1.18 50 2.51 2.15 1.95 1.84 60 4.25 3.57 3.19 2.96 The glass stress (fbt) for other glass thicknesses (t) may be reasonably estimated by multiplying the stress from the table (fb)by t2/0.4692: fbt=fb* t2/0.4692 FEA models show this will be within±5% of the stress determined directly by FEA model for the alternative glass thickness. Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- : ' : . Gig Harbor,WA98335 fax 2'iAL :�':- 1.VEL� email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 25 of 31 lOpsf Wind Load Glass Stress,Assuming 6in=0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) Glass IMIErillMit".1th (in) 36 48 60 72 36 2750 3482 4254 5056 42 3882 4889 5948 7045 50 5694 7580 8652 10210 60 8447 10550 12750 15020 Glass Stress,Assuming 6in=0.469" (1/2" Monolithic nominal), 3 pairs Glass Height(i lass Width (in) 36 48 60 72 1 36 2031 2433 2864 3367 42 2882 3483 4083 4735 50 4426 5279 5986 6930 60 6658 7914 9242 10700 Glass Deflection,Assuming 6in=0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) IIIIIM Glass Width (in) 36 48 60 41572 36 0.214 0.269 0.329 0.397 42 0.385 0.474 0.571 0.676 50 0.747 0.903 1.07 1.25 60 1.49 1.77 2.07 2.38 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- : ' : . Gig Harbor,WA98335 fax2':�L : -.1 VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System —SRS 10/16/2019 Page 26 of 31 Glass Deflection,Assuming train=0.469" (1/2" Monolithic nominal), 3 pairs lass Height(in) Glass Width (in) 36 48 60 72 36 0.161 0.191 0.222 0.254 42 0.296 0.347 0.400 0.454 1 50 0.589 0.680 0.774 0.872 60 1.21 1.37 1.54 1.72 6"Vertical Standoff Spacing 50p1f Live Load Glass Stress,Assuming train=0.469" (1/2" Monolithic nominal), 2 pairs Glass Glass Width (in) 36 48 60 72 36 8442 10300 12240 13930 42 10400 12280 14580 16960 50 12940 14950 17700 20560 60 15530 18340 22600 25050 Glass Stress,Assuming tmin=0.469" (1/2" Monolithic nominal),3 pairs Glass Height(in) 11. 11=11.= Glass Width (in) 36 48 60 72 36 6785 7864 9009 9809 42 8249 9511 10860 12190 50 10900 11800 13370 15060 60 13280 14900 17708 19160 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- : ' : . VEDGig Harbor,WA98335 fax2':AL : - 1 email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 27 of 31 Glass Deflection,Assuming 6;n=0.469" (1/2" Monolithic nominal),2 pairs lass Height(in) Glass Width (in) 36 48 60 72 36 0.582 0.687 0.807 0.946 ' 42 0.935 1.08 1.24 1.43 50 1.59 1.80 2.03 2.29 60 2.77 3.08 3.42 3.79 Glass Deflection,Assuming tm;n=0.469" (1/2" Monolithic nominal), 3 pairs Glass Height(in) I I r Glass Width (in) 36 48 60 72 36 0.480 0.532 0.587 0.645 42 0.791 0.864 0.943 1.03 50 1.38 1.49 1.61 1.73 60 2.46 2.62 2.79 2.98 200#Live Load At Corner Glass Stress,Assuming 6in.0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) IIIII Glass Width (in) 36 48 60 72 36 1 13700 13670 14000 14330 42 16330 15580 15790 16200 50 18850 18190 18230 18550 60 22580 21520 21280 21470 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- : ' : . Gig Harbor,WA98335 fax2':AL : -.; VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 28 of 31 Glass Stress,Assuming tmin=0.469" (1/2" Monolithic nominal),3 pairs lass Height(in) Glass Width (in) 36 48 60 72 36 10780 10720 11340 12500 42 12840 12550 13260 13890 50 15080 14420 14540 15290 60 18300 17070 16410 16690 Glass Deflection,Assuming tnnin=0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 0.936 0.914 0.935 0.982 42 1.45 1.37 1.36 1.40 50 2.38 2.17 2.11 2.11 60 4.02 3.55 3.35 3.27 Glass Deflection,Assuming tmin=0.469" (1/2" Monolithic nominal), 3 pairs Glass Heigh Glass Width (in) 36 48 60 72 36 0.812 0.790 0.814 0.862 42 1.27 1.18 1.18 1.21 50 2.10 1.88 1.81 1.81 60 3.60 3.10 2.88 2.80 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- : ' : . VED Gig Harbor,WA98335 fax2'iAL : - 1. email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 29 of 31 200# Live Load At Center Glass Stress,Assuming train=0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 10860 9874 10290 9590 42 13030 12270 11710 11400 50 16410 15420 14200 13780 60 20240 18300 17320 16760 Glass Stress,Assuming train=0.469" (1/2" Monolithic nominal), 3 pairs Glass Height(i lass Width (in) 36 48 60 72 36 9291 8433 8127 8158 42 11150 9917 9466 9895 50 13630 12360 11500 11120 60 18020 15060 13880 13280 Glass Deflection,Assuming tmin=0.469" (1/2" Monolithic nominal),2 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 0.803 0.739 0.735 0.767 42 1.27 1.13 1.08 1.08 50 2.15 1.85 1.71 1.65 60 3.72 3.13 2.82 2.65 Edward C.Robison,P.E. 10012 Creviston DR NW 25 •: ;•e-: Gig Harbor,WA98335 fax 2':�L : - 1 VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System — SRS 10/16/2019 Page 30 of 31 Glass Deflection,Assuming 6;n=0.469" (1/2" Monolithic nominal), 3 pairs lass Height(in) Glass Width (in) 36 48 60 72 36 0.664 0.573 0.53 0.511 42 1.08 0.907 0.819 0.775 1 50 1.87 1.53 1.36 1.25 60 3.30 2.66 2.31 2.09 10psf Wind Load Glass Stress,Assuming tmin=0.469" (1/2" Monolithic nominal), 2 pairs Glass Height(i lass Width (in) 36 48 60 72 36 2071 2568 3370 3814 42 2968 3781 4572 5388 50 4540 5782 6723 7887 60 6863 8381 10000 11690 Glass Stress,Assuming train=0.469" (1/2" Monolithic nominal), 3 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 1 1633 1923 2224 2556 42 2385 2785 3233 3909 50 3603 4323 4946 5608 60 5884 6545 7481 8469 Edward C.Robison,P.E. 10012 Creviston DR NW 25 .:- ; ' : . Gig Harbor,WA98335 fax2':AL . -.; VED email: elrobison @ na 0 4%.� /2 0 21 ASPEN BUILDING DEPARTMENT CR Laurence Standoff Rail System —SRS 10/16/2019 Page 31 of 31 Glass Deflection,Assuming 6;n=0.469" (1/2" Monolithic nominal),2 pairs lass Height(in) Glass Width (in) 36 48 60 72 36 0.124 0.151 0.185 0.225 42 0.235 0.279 0.331 0.39 50 0.482 0.559 0.646 0.743 60 1.02 1.16 1.31 1.48 Glass Deflection,Assuming tnn;I,=0.469" (1/2" Monolithic nominal), 3 pairs Glass Height(in) Glass Width (in) 36 48 60 72 36 0.098 0.111 0.124 0.138 42 0.191 0.213 0.237 0.262 50 0.404 0.443 0.486 0.532 60 0.873 0.945 1.02 1.11 For all tables in Appendix A The glass stress (fbt) for other glass thicknesses (t) may be reasonably estimated by multiplying the stress from the table (fb)by t2/0.4692: fbt=fb* t2/0.4692 The glass deflection (At) for other glass thicknesses (t) may be reasonably estimated by multiplying the deflection from the table (A)by 0.4693/t3: At= A* 0.4693/t3 Edward C.Robison,P.E. 10012 Creviston DR NW 25 VED Gig Harbor,WA98335 fax2':�� . email: elrobison@na 0 4%.c 1/2 0 21 ASPEN BUILDING DEPARTMENT