A COKPARATIVE ANALYSIS OF .ALUHIDHEI STEE ifiND'XOOD AS STRUCTURAL MATERIALS By Clarence E. Dennis fl“...— A-Thesls Submitted to the Graduate School of Mlchiran State College of Agriculture and Anplled Science in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE Department of Civil Engineering 1950 THES‘S ACKNOWLEDGEMENT The writer wishes to express his appreciation to Dodtor Charles 0. Harris, Prof. C. A. Miller and Prof. William A. Bradley whose helpful suggestions and guidance made this thesis possible. 9900;3{3 TABLE OF CCHTEFTS I. Introduction (1) Method of Approach . . . . . . . . . . 2 (2) Method of Presentation . . . . . . . . 2 II. A Brief History of the Katerials (1) Wood . . . . . . . . . . . . . . . . . 3 (2) Steel. . . . . . . . . . . . . . . . . 4 (5) Aluminum . . . . . . . . . . . . . . . 5 III. Desisn Considerations (1) Physical Pronerties. . . . . . . . . . 6 (2) Special Considerations . . . . . . . . 8 (3) Maintenance. . . . . . ... . . . . . . 14 IV. Conclusions. . . . . . . . . . . . . . . . . . . 15 V. Deck Plate Girder Railroad Bridge (hiveted Steel) . . . 20 VI. Deck Plate Girder Railroad Bridge (Welded Steel). . . . 59 VII. Deck Plate Girder Pailroad Bridge (Aluminum). . . . . . 72 VIII. Wooden Girder Railroad Bridse. . . . . . . . . . 95 APPEEDIXES I. Specifications for the Design and Fabrication of Structures of Alcoa Aluminum Alloy SlS-T. . . 1 II. Bibliography . . . . . . . . . . . . . . . . xxviii I. INTRODUCTION It is of prime importance for structural designers to not only understand the mechanics of desian; but to also understand the relative merits of the materials which are available for design. In the literature of today, material is beginning to appear that leads one to believe that all designs are econ- omically feasible with all materials. This, of course, is too broad a statement to be completely true. The purpose of this thesis is to investigate the rela- tive merits for use in heavy structures of three materials. Namely, wood, steel and aluminum. Wood is chosen because it is the oldest known structural material. A material which has only recently been reiuvinated in the heavy structural field by the discovery of the high frequency slueina process for laminated members. Steel is chosen because it is the most commonly and widely used material in the field today as well as being the material which has grown up with civilization. Its develon- ment follows very closely that of civilization. Steel is used as the basis for comparing the other materials. Aluminum is chosen because it is the new, youns material in the structural field. Its development has been extremely rapid and it is now biddina for a place in the design of structures with heavy live loads. The use of all three of these materials in members with simple tension, compression and bendina is well known. The choice of material for such a member being based upon to availability, cost and weight of member. It being gener- ally understood that the lower specific gravity of aluminum and wood make them very desirable where dead load is a high percentage of the total load. The desirability of these materials in replacina steel in structures where the live load predominates is in question. It is with this asoect that this thesis treats. (1) METHOD or APPROACH After careful consideration of several posibilities of aoiroach to the problem of comuarins these materials deck plate girder bridges were decided upon. Deck Plate girders were chosen because: (a) Girders are a well known standard form of heavy structure. (b) Girders embody the features of crumulinq and buckling which are the maior features that cause one desisn to vary from another in a manner other than the variation of allowable stress. (0) On girders of this type live load is the predom- inating feature in determ nina stress; dead load being a very small percentage of the total load. (d) Aluminum and wooden girders for this type of loading are very rare and little is known of them. (2) METHOD or PRESENTATIOI The facts concerning Steel, Aluminum and Wood are presented in Chapters I, II and III. Gider designs of Rivited Steel, Welded Steel, Aluminum and Wood are in Chapters V, VI, VII and VIII. Supplementary Specifications to the A.R.E.A. specifica- tions for Aluminum are in the appendices. The conclusions based on this material are in Chapter IV. This method of presentation was chosen as teinq the most convenient for the reader. References are listed by number in the Bibliography and are indicated in the text by use of these numbers. Standard Specifications are assumed available to all interested readers and are referenced accordingly. II. A BB”EF HTSTORL OF TVE T TFRTALS (1) Wood Wood is the oldest structural material known to man. This is true becarse of two things: 1. Because of its accessibflity on the face of the earth. N 0 Because of its workability; it could be cut and shaped even by the crude instruments of stone of early man. The difference in allowable stress with and asainst the grain combined with its limited size; that of the larqest tree; made wood structrually adaptable only to small members. It is very interestina to note that the method by which wood has finally come into the heavy structural field was used by the Egyptians. In the tombs of the Pharaoh's have been found examples of laminated wood. This wood was used as an inlay for beau— tification and down through the centuries cabinet makers have used laminated wo d. This laminated wood gradually became the plywood of today. Laminated wood was still not ready as a heavy struc- tural material because the glue with which laminates are made was set by exposure to the air. Laminates of over one inch were not practical and even then the slue between each lamination took a long time to set. Uncertainty as to the efficiency of setting of the glue plus large cost of manufacture made these heavy struc~ tural members prohibitive. During the second world war the high frequency gluing method was discovered whereby laminations of any nuvber and any thickness may be glued at once into a single structural member. Improvement of glues to a point where they are stronger than the wood itself plus iudicious positioning of laminations results in a member whose allowable stresses may be made equal in all planes. Wood again has entered the heavy structural field. . (2) STEEL The use of iron like that of word is traceable back: before the dawn of history. Also like wood, many hundreds of years passed before any significant change in the manu- facture of iron occured. Iron has been used down through the ages from the times of the Bible down to the oresent day to make cuttins instruments and weapons of war. Iron instruments were used in the building of the pyramids. Today iron is the most widely used metal on the face of the earth. The art of producing crucible steel was known and practiced in ancient India. It was then forgotten for hundreds of years until in 1442. Benjamin Huntman redis- covered it. This process with only minor variations is still used in many countries today. In 1784 Henry Cort patented a process for converting pia iron into wrought iron. This was the first fundamental change in the iron industry for many centuriesl)° In 1885 Sir Henry Bessemer invented the Bessemer process for making steel. This made possible “or the first time the makina of steel on a large scale and maybe listed among the outstandins discoveries of the present time insofar as effect on ensineerina is concerned. (3) ALUIZINUM Aluminum, the most abundant of all the metallic ele- ments found in the earth's crust2)unlike steel and wood was not discovered until recent times. In 1825 Hans Christian Oersted announced to the Royal Danish Academy of Sdences that he had obtained aluminum by gently heating aluminum chloride and potassium amalgam. This was the first time that anyone had succeeded in freeing aluminum from the compounds it occurs in in the earth's crust. In the next sixty years the discovery of cheaper reducing agents reduced the price of aluminum from 8545 a pound to $17 a pound but the production was still only a few tons per year. In 1886 Charles Martin Hall, at thattime only twenty- two years of age, succeeded in separating aluminum by the electrolytic process. Working independently Paul Louis Toussaint Heroult, discovered the same process. He was also only twenty-two years of age. The discovery of the electrOLytic process enabled the production of aluminum on the large scale upon which it is produced today. III DESIGN CONSIDERATION (1) Physical Preperties The physical properties of steel are taken where applicable from the American Railway Engineering Association Specifications for Steel Railway Bridge, 1941. Those of aluminum from Specifications for the Design and Fabrication of Structures of Alcoa Aluminum Alloy 615-T as recommended by the Aluminum Company of America. Those for word from the National Desiqn Specification for Stress Grade Lumber and its Fasteninss 1944 as modified by Bulletin VK-8, Glued Laminated Specifications, January 10, 1949 by Timber Structures Inc. Weight: Aluminum = 169 pounds per cubic foot Steel = 490 pounds per cubic foot Wood - 60 pounds per cubic foot (Approx) Modulus of Elasticity: Aluminum : l0,009,000 lbs. per Sq. in. Steel 30,000,000 lbs. per sq. in. Wood 1,800,000 lbs. per sq. in. Coefficient of Expansion: Aluminum - 0.000 015 Per degree F Steel = 0.000 0065 Per desree F Poisson's Ratio Aluminum = 0.33 0 Steel 8 -930 Allowable Unit Stresses: Axial Tension (Net Section) Aluminum = 16,000 0.9.1. Steel - 1e,ooo p.s.i. Tension in extreme fibers of rolled shapes, airders and built sections, subiect to bending. Aluminum - 16,000 p.s.i. Steel _ 18,000 p.s.i. Stress in extreme fibers of nine Aluminum 3 24,000 p.s.i. Steel - 27,000 p.s.i. (2) Shear in power driven rivets Steel - 13,500 p.s.i. Aluminum Cold driven 615—T _ 10,000 p.s.i. Hot driven 835 8,000 p.s.i. Shear in turned bOJtS Aluminum a 10,000 p.s.i. Steel = 11,000 p.801. Special Considerations Axial Compression (Gross Section) Stiffeners in plate girders Steel 3 18,000 p.s.i. Intermediate stiffeners: If the depth of the web between the flanges or side plates of a plate girder exceeds 60 times its thickness, it shall be stiffened by pairs of angles welded to the web. The clear distance between stiffeners shall not exceed 72 inches nor that given by the formula: d a 255,00ot (st)i/s S a d . clear distance between stiffeners in inches t . thikness of web in inches a a clear depth of web between flanges or side plates in inches 8 - unit shearing stress, gross section, in web at point considered. Aluminum = 6.13 t3h When s/h : or less than 0.4 IB When s/h is greater than 0.4 IS = t3h STE/h4) (s/h)2 plus 0.625) Where I - required moment of inertia of stiffener in inches4 t = thickness of web in inches 5 = required stiffener spacing as given by formula for critical shear buckling stress h z clear height of web in inches Critical shear bucklina stress = 51,000,000 #42 t unsupported width of plate in inches 0’ ll d’ II thickness of plate in inches Centrally loaded columns Steel L not greater than 140 r Riveted ends 2 15,000 ~ 1/4 L2 F3 Pin ends = 15,000 — 1/3 L3 .2 10 1” L = lenath of member in inches r : least radius of ayration of member in inches Aluminum g equal to or less than 100 r p 17,000 - 100 p but not to exceed 15,000 p.s.i. a r Where p equals the greatest slenderness ratio of the 1‘ member Compression in extreme fibers of rolled shapes, girders and built sections, subiect to bending. Steel For values of L/b not greater than 40 s = 18,000 - 5 L2 S? L = lenath in inches of unsupported flanae be— tween lateral connections of knee braces b 2 flange width in inches Aluminum Basic allowable compressive stress as given alone shall govern except providing that the equivalent radius of ayration of the compres— sion flange is determined in accordance with the following formula: 11 Equivalent radius of ayration of compression flanges a 0-2 (I. (J(KL)2 plus 13.1 If 02)1/2 "ST ( Where s0 3 Il - L :2 K : If g d : J 3 Where 1 = b = t - ) section modulus for beam about axis normal to web (compression side) in inches to the third power. _ moment of inertia for beam about the principal axis parallel to web in inches to the fourth power. laterally unsupported length of compression flanae in inches. factor representing end conditions of later— ally unsupported length. ”moment of inertia of compression flanae of beam about axis parallel to web (may be assumed equal to 1/2 of I, in case of I shaped members having both flanges alike) in inches to the fourth power. A depth of beam in inches torsion factor in inches to the fourth power. the sum of 1/3 bt3 (See ALCOA Spec. 3) lenath of each separate rectangle in member in webs - thickness of each separate rectangle. Horizontal stiffeners Steel 12 (Not necessary) Aluminum Horizontal stiffeners shall have a radius of 2y- ration not less than that aiven by the following formula: 1" Deflection: H or (11)2 r x 10.9 t required radius of ayration of one stif- fener in inches. clear heiaht of web in inches web thickness in inches compressive stress at toe of flanae angles in p.s.i. a coefficient which depends upon the ratio of the spacina of the vertical stiffener, s, to the clear height of the web, h. Values of or found in Table IV of Speci- fications. Assume an equivalent uniform load such that the moment at the center equals 73,700,000 in. 1b. 73,700,000 wL2 "e‘ W: 73,700,000 x 8 840 x 840 - 825 pounds per foot Steel: Steel: Deflection 5wL4 Average I . 170,400 in4 584EI 5(825) (840)4 384 x 30 x 106 x 170,400 1.08 inches Aluminum: W i fld Cost: Deflection 5wL4 I . 267,700 1n.4 384 El 5(825) (840)4fi 384 x 10 x 100 x 287,700 1.95 inches Load: Steel : 640 pounds per foot Aluminum = 732 pounds per font Steel (See Bill of Materials) Riveted 67,205.8 pounds @ Welded 62,594.3 pounds @ 13 Aluminum (See Bill of Materials) 34,365 pounds @ 37¢ Wood 40,320 F.B.Y. @ 255.50 Freight to Lansing Creosote (3) Maintenance Steel: Prime Coat Cost Coverage Finish Coat Cost Coverage Aluminum: Prime Coat Cost Coverage Finish Coat Cost Coverage Total Red Lead 04.00 per gallon 1,000 sq. ft. Aluminum Paint 0 .00 per gallon 1,000 sq. ft. Red Lead £4.00 per gallon 1,000 sq. ft. Aluminum paint $6.00 per gallon 1,000 sq. ft. 14 $12,715.05 $10,300 800 312,340 IV CONCLUSIONS The conclusions that follow include a consideration of the past, the comparrisons of the present, and a tenta- tive look into the future. The facts are presented as they exist today and as nearly corwect as available informa- tion can make them. The suggestions as to the future are the author's own and are presented only as such. Wood has as yet not reached the staae when it is practical to build structures with heavy, predominamt live loads of this material. Fabrication and cost are still such as to make feasibility of such construction economi- cally unsound. It is interesting to note, however, that an allowable bendina stress of 3000 pounds per square inch is now allowed for laminated members which is abrut one third greater than that quoted in any hand book published to date. At the same time, the method of desicn is the simple method which was probably the first case of bendina stress desian learned by the student of structures. Namely, a rectangular beam with known bending moment, shear and allowable stress whith a sinple substitution in the flex- ural formula S — MC 0 I Thus in at least one case progress has brought simp- lification rather than complication. The main comparison is left to one between aluminum and steel. 16 Stress comparison shows aluminum to be eight-ninths as strona as steel except when fully supported in which case it is of the same strenath. Bearina this fact in mind an investigation of other properties aives an indication of the maior points of differ- ence between the two materials. Aluminum weiahs approximately one-third as much as steel and has a modulus of elasticity of one-third also while its Poisson's Ratio is very nearly the same. A modulus of elasticity of one-third means an expan- sion or contraction due to stress of three times that of steel while its exoansion due to temperation is twice as great. This is the factor which causes aluminum desian to be more complicated than steel as well as making it necessary to use much more aluminum, in relation to its allowable stress than steel. For a aiven load and the same cross-section of material aluminum will chanae in lenath three times as much as steel. This makes aluminum three times as susceptible to crumplina and buoklina as steel. In the case of change of lenath due to temperature the factor is two instead of three but still in favor of steel. This results in the use of more and heavier vertical stiffeners plus the use of horizontal stiffeners for aluminum design. Steel of course does not require horizon- tal stiffeners. 17 In the case of column formulas aluminum in addition to using a lower allowable to start from also uses a much more conservative formula than does steel for the same situation. This also is directly traceable to greater change in length of aluminum than of steel under the same load and cross- section. Aluminum uses Johnson's straight line formula while steel uses Johnson's formula of the second degree. The steel formula plots much closer to the stress—l/r curve for values of 1/r less than 100. Aluminum uses the formula for equivalent radius of syration of compression flanges to desian these flanges. This formula aives a less conservative cross-section for lighter loads which gradually approaches the cross-section found by conventional methods such as the flanae area method and then becomes more conservative as the loads increase. The deflection of the steel airder is 1.08 inches while the deflection of the aluminum airder is 1.95 inches when the aluminum girder is one foot greater in depth than the steel. The determination of the deflection of the aluminum girder which is kept within an allowable amount by increasing the depth must be balanced against the increased need for stiffeners with increased depth. The deflection will be the maior control factor but care in keepina it close to the maximum allowable will allow the use of the minimum amount of stiffening. 18 (The deflection of the wooden girders will be 5 inches for the same case which is again prohibitive.) The wind load will be sliahtly greater on the alumin- mium girder because of its greater death. However, mini- mum anales are used in both cases because the load is rela- tively lisht. Therefore, there is no real difference between the two materials. The first cost of the aluminum girder is twice that of the steel. The unit cost of the aluminum being three and one-half times that of steel. In spite of the generally accepted Opinion that alumi- num maintenance has a comparatively low cost because it will not corrode; the facts indicate differently. The Aluminum Company of America itself in its speci- fications recommends painting exposed aluminum structures. The recommended primer and finish coats are exactly the same as recommended for steel. One paint company may recommed a different paint than another but for both aluminum and steel. If anything, the aluminum structure is more expensive because of its slightly greater surface area. It is true that aluminum is nonreactive with water. However, it is iust as reactive (some authorities say more reactive) with acids and caustics, as steel. The predom- inance of manufacturins in all areas of the United States means that there will be more or less caustics and acids in the air at all localities. Therefore protection in the form of paint is necessary. 19 Anadizina and bonderizins simply make the surfaces of aluminum and steel more acceptible to paint. A locality that requires this treatment for steel also requires it for aluminum. Fabrication of both materials is done in the same shops. As the shOps were originally set up for steel fabrication and the same machinery is used for aluminum there is very little difference in cost. What of the future of these materials? In order to suaaest What might happen in the future it is necessary to consider the past. Steel was develOped over a period of many centuries. Attempts have been made to use it for every conceivable purpose. Its usability has been pretty much standarized. This should not be construed as meaning that there will be no prosress in steel but only that it will probably be a steady gradual progress. Steel has huge facilities for experimentation with a monetary backing that is almost unlimited. This has been true for the last half century. Aluminum, on the other hand, has had only one century of use. Durina this century it has made extremely rapid advances. However, there are many fields where its usability has not been thoroughly tried. The finances available for eXperimentation has been only a fraction of that of steel. It is findine a place in a market already held by other materials. It must not only prove its practicability but also that is has greater practicability than an established material. ‘ Aluminum has approximately the same availability in the earth's crust as steel. It is almost a sure thing that better and cheaper ways of mininz and processing it will be developed. It is Just as sure that where it is more practicable, the world will accept its use and it will replace the materials now used. Aluminum has the advantage of being only one-third as heavy as steel while it has about the same strength. The time will come when progress in mining and proces- sing methods as well as in usability will decrease the cost of aluminum to a point where it will be Just as economical to use as steel. At the present time the conclusion drawn is that alumi- num while it is practicable as a material for structures that have a predominance of live loads, it is not as yet more practicable than steel. V DECK PLATE GIRDER RAILROAD BRIDGE (RIVETED STEEL) Data and Specifications Single Track Span = 70'-O" According to A.R.E.A. “Specifications for Steel Railway Bridges" 1941 Live Load COOpers Standard E—72 Loading Alternate Load = 2-90,000# Axels Spaced 7'-O" c to c 21 c to c of main girders (Spec. 103) . 1/15 x 70 = 4.66' less than 6'6“ Use 7'-O" Design of Ties Live Load on each tie at each rail . 1/3 x 90,000/2 = 15,ooo#. No Imoact (Spec. 301). Assume wst. of floor (Ties, guard rails, steel rails fasteninas) : 700# per tie concentrated at rails. Total concentration :‘15,000 plus 350 = 15,350 . ' i" Q” I :11 . ,. i l ' ., , . a L e >~- ----—L 7 'l f I, It I ~-\\_ r0 xix? sio 77c ,/¢//’ / l \-.. .N- 5'4‘.‘ l‘_‘ ,, n f . G'BGuardQcH/ . . l ,1. .' n? ? I I/ - ‘ , ‘7 f' 9,--91‘9 cl New. Grrde rs . - ..-..._ _ J AAALJL‘ -A;L ii ‘ _ all Fig. l 22 Mmax = 15,350 x (7.0 - 5.0) X 12 = 184,000 in.# 2 N = s l = f bh2 c 6 SWt = lSOO#/ch In. (Spec 301) Yellow pine bh2 = 184,000 x 6 = 738 1n3 1500 Use a lOll x 10" Tie bh2 = 10 x 102 - 1000 1n3 Length Tie lO'-O"; (Spec. 109) Spacing - 4" > Wat of F loor_per Tie 10 x 10 x 10 x 60 = 417# 12 x lg Guard Rails : 2 x 6 x 8 x 60 x 14 = 47# 144 12 Steel Rails & Fasteninas = 200 x 14 235# I? 417 plus 47 plus 233 u 697# Assumed - 700# OK Design of Main Girder Wgt of floor per lineal foot : 12 x 697 a 598# l 23 _ Formula for assumed wst of girder and 1/2 bracing ex- clusive of the floor system = k (12.5L plus 100) 8 ll ml 2 II 1.22 (12.5 x 70 plus 100) : 6l5# 2 t—q I _ Span in feet k 1.22 for E-72 loading Total D.L. per foot of girder - 615 plus 697 = 964 Use 1000#/ft. Max Moments & Shears (See loading tables in appendix F, Sutherland & Bowman, Structural Design) Cooper E-lO Loading x 7.2 : Cooper E-72 Loading. Max. L. L. Moment under WH 15 at center line of span Moment about wh 18 2 2508.5 x 7.2 = 9051 Kip ft. 2 Wat of wheels ; 84 x 7.2 502.4 Kips 0 K2 0 I CO O ()3 H I ()3 O I _ at wheel 15 Place wheel 15 at center line of span 24 t ’f 47—"__“”“ “ _ W“ s... -_ _- 13:3 QL 4......”0-.. i, ,_,__ _ “q 70, _ H_“ D * __ F12. 2 fiR- ; 9051 plus 502.4 x 5 RL = 10,545 = 150.6 Kips R 70 = 9051 plus 1512 MMax = 150.6 x 55 - 505.25 x 7.2 = 10,545 Kip ft. 3 5271 - 2198 = 5075 Kip ft. MAX MOMENTS IN KIP-FEET Distance from . Support, Ft. 10 2O 50 55 Dead Load 500 500 600 612.5 Live Load 1,554 2,528 5,006 5,075.0 Impact 1,212 1,970 2,544 2,598.0 Total 5,066 4,998 5,959 6,085.5 Total In.—Klps 56,792 60,000 71,410 75,000.0 Dead Load Moments: RL 3 M @910 1 1000 x 35 - 35k 55 x 10 - 10 x 1 X 5 : 500 Kip-ft. 25 h@fi : 55 x 20 - 20 x 1 x 10 _ 500 Kip—ft. i@50' = 55 x 50 - 50 x l x 15 _ 600 Kip—ft. 55 x 55 - 55 x 1 x 17.5 = 612.5 Kip-ft. @) M II Live Load Moment /‘* -. + / ~ ~.. ._, HD- I m r «a- /"P\ ’ 1‘- K 1,} “ «— _‘ a h i l 4‘ r. -...____ w... ..._ .. a-.. .. - _ .— V 4 . 0 A 0 to L ‘ F3 i ’ 3 A. ~— L 7““ Y_ ___,__ Hm-___ ____._.___.~_,_.__.._,J L F: 0 F12. 5 Max M@lo (From Table 2 Max Moment — WH 3) ~ 2 Sum of the weight of wheels = 96.0 - 5.0 x 7.2 = 527.9k 2 M12 plus 527.9 x 4 {IO :11 II 10,825 plus 1511 12,136 26 RL - 12,136 = 173.4.k 70 a I ' lO 2 1754 - 180 1554 Kip-ft. Max M®20' (From table 2 Max Moment ~WH 12) Sum of Wat. of wheels 3 142-71 x 7.2 = 256k __7?__. id : M18 plus 256 x 15 plus 10 x 7.2 x 5 RR “2‘ : 6280 plus 5858 plus 180 = 10,298 Kip-ft. RL 3 10,298 . 147.1k "1TT" M@ 20' 147.1 x 20 — M12 2942 - 112 x 7.2 2 s 2942 - 414 a 2528 Kip-ft. F12. 5 Max M@ O' (From Table 2 Max Moment - WH 12) 3 M618 3 2528.5 x 7.2 a 9040 Kip-ft. Sum of Wat. of Wheels = 142-58 x 7.2 = 302.2k " 2 27 ERR M18 plus 302.2 x 5 = 9040 plus 1511 RL 4 10,551 . 150.7k 70 I”:L@3()_. 150.7 X 30 "" 25.12 : 4521 — 1515 = 5005 Kip-ft. Impact: (AREA) Rolling Effect - 20% Direct Vertical Effect 100-.5 x 70 (See A.R.E.A. Spec. 205(5) ) Total Impact: @ 10' z 1554 x .79 - 1212 Kip-ft. 28 29 0 20' 2528 x .72 = 1970 Kip-ft. @ 50' 5005 x .78 = 2544 Kip-ft. @ 35' 3073 x .78 - 2398 Kip-ft. flax Shears in 1,000 L0. Dist. Fm. Supoort In Feet 0 10 20 30 35 Dead Load 35.0 02.0 15.0 5.0 0 Live Load 199.1 150.1 109.0 71.7 55.5 Impact 155.4 117.2 25.1 55.9 45.0 Total 599.5 292 5 209.1 152.6 92.5 Dead Loud (W : 1000#/1) At 0 vO . 1 x 70 z 55k At 10' V10' = 55 - 10 = 25k At 20' v10' = 55 - 20 . 15k At 50' V50' = 55 - 50 = 5k At 55' V55' = 55 - 55 = 0 Live Load Shears (Max Shear when NH 2 is at Point for 911 cases) 30 12 E (2“ l ~ 21/. - r _,1 - - 1-- .1.. ,1 - .}_.__. .1 . EL - '70_ F19. 6 M13 . 5454 x 7.2 . 12,490 Kip-ft. Sum of Wzt. of Wheels _ 106-5 x 7.2 . 363.9k : 12,480 plus 1,455 : 15,955 Kip-ft. ”A _ k V0 3 RL . 13380 _ 199.1 <‘.‘ 10' .. . v 7’ .‘7 “1'3 54- , ‘\ L\ 1 (32 Q i ~. .. .. a " 1 L... i .. ______ ____.__. _. u -. ,, , ._1 r.‘ 1 7“ Sum of wet of wheels 3 309.8 f _ M11 plus 309.8 x 4 10,530 plus 1239 V0 - BL - 5 x 7.2 a 11 769 - 18.0 ' '2 ' 70" 168.1 - 18 k Fig. 8 ’7‘ Sum of Wat of wheels - égx 7.2 = 273.6 M10 plus 273.6 x 2 M RR 9540 plus 547 9997 Kip-ft. 31 V20' RL - 18 8887- 18 10 127.0 - 18 109.0k V 1748 x 7.2 RL - 18 6280 - 18 70 89.7 - 18 71.7k I -I h %._~...‘_.._._..._ _......--_-_....~..__... .. -. Fla. 9 5,290 Kip-ft. 79.1.--. -e _. all ' L. Elihu“... -__.______.._”:’.:~> -_ F12. 10 I? r 1425 5 7 5 13021 1.1% : J8 : o X 92 = , v35. = RL - 19 5130 - 18 70 — 55.5k Impact At 0' = 199.1 x.78 4 155.4k At 10' = 150.1 x.78 = 117.2k At 20' = 109.0 x.78 = 95.1k At 50' a 71.7 x.78 = 55.9k At 55' 55.5 x.78 = 45.0k Pesxign of Web (AREA - Depth not less than 1 L) 12 .54 D - 1 x 70' = 70" E> For economy use D : l x 20 x 12 = 84" E5 Req. Web Area _ 389,500 : 35.4 Sq. In. (Spec 301) 11) LCD . Thickness Req. 35.4 = 0.422“ ‘8‘— t not less than 1 Clear distance between flanges) 150 (Spec. 451) Assume vertical less of flange angles = 6" and distance B to B of flange angles 1“ greater than 2 depth of web. Therefore: t g 84.5 = .497" Use 1Z2" 170 Desisn Flanges: Assume effective depth 2 84.5 Max Flange Stress = 73,000,000 = 864,000# 84.5 Total effective net flange area req. : 864,000 = 18,000 48 Sq. In. 35 Equivalent flange area of web (1 x gross area) 1 X 84 X 1 : 5024 sq. In. 8 2 Net area req. in flanges and cover plates _ 48—5.24 42.75 Sq. In. Assumed Section: No. of Gross Rivet Area of Section Area Holes Rivet Holes Net Area 2 Angles 6x65; 19.46 Sq In 4 3.00 Sq In 16.46 Sq In 2 Cover Plates 1553 22.50 Sq In 4 3.00 Sq In 19.50 Sq In 4 1 Cover Plate , 15x;% 8.43 Sq In 2 1.13 Sq In 7.30 Sq In 1 Total 50.39 Sq In 43.26 Sq In Net area cover plates : 26.80 = .598 less than 2 95 45.25 3 F12. 11 ‘4! 50.39 29900 = 5095 507% OK Use h': 84.4" a 84.5-.05 x 2 = 84.4" Lengfibs of Cover Plates Résistina Moments 3 M a (A: plus l/8Aw) x h x 18,000 Net Area Total Eff s& Covers 1/8AW Net Flange h Sq; In. §g_;g Area Sq In 13 2 angles plus 3 Covers 45-26 5.24 49.50 94.4 2 angles plus _ 2—5/4" Covers 35.96 5.24 41.20 95.7 2 angles plus 1-5/4" Covers 26.21 5.24 51.45 92.5 2 angles 16.46 5.24 21.70 80.9 2 angles plus 3 covers M 49.50 x 94.4 x 19,000 = 75,700,000 in/lb 2 angles plus 2 — 3/4" covers § I 6.75 X 22050 DADS 8105 Base angles 41.96 155.75 plus 91.5 41.95 235.25 = 5.61" 41.96 Therefore D : 84.5 — 2 x . 39 D - 83.7 Use = 8405 — 078 2 angles plus 2 — 3/4" Covers 37 M (In—lb) 73,700,000 62,100,000 46,600,000 31,600,000 2 angles plus 1 - 3/4" Cover 5 = 6.375 x 11.25 plus 81.5 Base of anqles 30.71 71.8 plus 81.5 30.71 5.0” 82.5“ 31.45 X 82.5 x 18,000 = 46,600,000 1n.-1b. ’— ll 2 angles D 84.5 - 1.82 X 2 8405 " 3064 80.86" {rat r?" II 21070 X 80.9 x 18,000 = 31,600,000 ino'lbo 38 39 nt;‘l|.|.. .I( v0.9 130.1,"! :1.‘ 4 o +wwxcdktoo~d3m €0.10. 5020.120 2. . 0w . m. fl nil H L .‘i‘ciis 11 O. m 0 all" 'n'llilllll"- lamwufiouoflow whom M. I I ll unantuagxnu: WENXWMWMQ . I ao/uq)-'ut U! squad/0w Summary: Top 1 - Cover 1-- Cover 1 ~ Cover Bottom 1 - Cover 1 - Cover 1 - Cover 15H 15H 15H 15" 15" 15" 40 9/16" x 30'-0” plusor minus 3/4" x 38'-0" plus or minus 3/4" x 70'—O” plus or minus 9/16" x 30'-0" Plus or minus 3/4" X 38'-0" plus or minus 3/4u x 56'—0" plus or minus Pitch of Rivets in Verticle Less of Angles PITCH 0F RIVETS JOINTNG WEB AND UPPER FLANGE 41 m (0 o 2 sue o 59 ”1‘1 0 <1: . “ C? (If (D- 0" N 5 5 “ 5;? 360‘” 5 m c .4 ct as; :44. :4 C 03 (1'3 H H A5 H .5 c~ c5330. >4 ‘00 t? p" ° 03-4 ‘ 1 1 0 , ‘0 "C: m. s 5 g": 2:99 49 1:99 9. .9 ‘0'” 0’ <3 CD :0 ,._‘l u . o h.- . E: w . m:: I Sr! r» .Qrd . :0): 0 ($6 (CF-40" “41:4?" H +3 o o omk-‘gl «3,3,; g ,5 5:5 592.; 255:. '15 5;“: any, 0) [fl éhggy lgégérté <:§* >ek m~¢ Qua a 0 389.5 82.5 30.71 35.95 4030 2025 4475 2.64" b 10 292.3 82.5 30.71 35.95 3030 2025 3590 3.29" 2025 C 12 275.0 82.5 30.71 35.95 2850 2025 3480 3.40" d 12 275.0 83.7 41.96 47.20 2920 2025 3540 3.34" e 20 209.1 83.7 41.96 47.20 2224 2025 2995 3.94" f 20 209.1 84.4 50.39 55.63 2241 2025 3008 3.93" 2 30 132.6 84.4 50.39 55.63 1424 2025 2460 4.80" h 35 98.3 84.4 50.391 55.6% 1053 2025 2261 5.22'| "C31 ., 3| II. III tullllu .r - N: 04.1 al' .1 .11, 11] .I II. II 1.1! 0.1 5.. .w 1 l . I I . .l 1. Let. I I... . . l 1 .1 l ‘11.. TI‘I’I 1‘ ‘1 III A. .l I . . I. ll ’ .l l‘ . . . ‘ Iv ll... ((2. v _ . m -. a -1. 01.1191 .9..." I. I to .1“ v on :37... Il..l.lll..1. .21.... 1 I It I I. I .0 I‘\ Ii..|‘J-. A 11 f 1']?! I'll-1...! II! 1. .9 ‘ I .1. I. J} {ill-3.9.0.14“! .II’ .111 II 1"!§11I 1115.10!“ ‘1. . C u . . .... J 4 (.I t. .l» l .1- II .I ll . Ill). OI . 1 I , o :1 L I . .. . II 'I' . I . ’ IIIII 4*. 111.7. (III-“Ir! I- . I. I‘ll! . l . .I at i .,11 1— I... .U. 1. 9 . I. 11L 0 {T} ‘3 I. ill-I AI" -3.-- ll fi'.'tol|'a4v G -nmwul. C. .M.an.....u__.d.,...,0 5:0 7‘ .1 l. J .11 I . .r - n) P U .. C u. .1! x r\ r.\ r\ | lill... J v in z r... - .Ii:. 31..-. . . .., 1. 1-. ... .. .. 13.1.1.3: . . ...-c....:!ll!t... ...... “'11.. '1'.”- Wp ma- » vex.- Q U -19.. h. it]! 0920 AU C.) O m MOON Joaqg U! ”300‘ 43 Horizontal Increment of Fiance Stress (Upper Flange) V H.I. E XAf Af plus 178 Aw Pt(a) = 599.5 x 50.71 x 1000 = 4,050” ' 92“. 5 23575. ‘5 Pt(b) : 292.5 x 50.71 x 1000 = 2.0304 92.5 55.95 Pt(c) = 275.0 x 50.71 x 1000 = 2,950# 99.5 55.95 Pt(d) = 275.0 x 41.95 x 1000 = 2,920# 95.7 42.20 Pt(e) : 209.1 x 41.95 x 1000 = 2,224# “9577 47720 Pt (f) =209.l x (n O rA LO >4 1000 = 2.241# (I) 2 ,p. ()1 O) l 03 C251 Pt(9) = 152.5 x 54 59 x 1000 = 1,424# 9434 55.55 Pt(h) = 99.5 x 50.59 x 1000 = 1,055# (I) ,1; ,p. 01 01 0‘) (.13 Vertical Increment of Flange Stress (Use one heavy driver over 3 feet plus flo r load) (Spec. 428) Resultant Increment of Flange Stress : 598 plus 72,000 X 2 = 25 :4. R.I. Pt(a) Pt(b) Pt(c) Pt(d) Pt(e) Pt(f) Pt(s) Pt(h) ( (4050)2 : ((H.I.)2 plus W2) (2025)2 )5 = ——— D *9 (20,001,525) : ( (5.050)2 ( (2.850)2 ( (2.920)2 ( (2.222)2 ( (2.241)2 ( <1.424)2 < (1,0552 plus plus plus plus plus plus plus NIH 4,475# 1 (2.025)2 )3 NIH (2,025)2 ) (uh- I (2,025)2 ) (2.025)2 )2 (20.5)2 ) 2 -1. (2,0202 )3 (2,025)2 )2 (9,000,900 (9,125,000 (8,525,000 (4,950,000 (5,040,000 (2,040,000 (1,111,000 plus plus plus plus plus plus plus 44 .11 (15,000,900 4,000,525)2 : 4,000,525%: 3,590# 4,000,000};= 3,480# 4,000,000%: 5,540# 4,000,000%: 2,9954 4,000,000%: 3,008# 4,000,000%= 2,460# 4, 000,000) 1. 2,261# 45 Bearing per Rivet Rivet Bearing Allowable - 27,000 1b./Sq.In. (Spec 501) Bearing per Rivet = 27,000 x 1 x g = 11,810 1b./Sq.In. 2 Pitch 0f Rivets Joining Web & Lower Flange '2 . ‘D 3 Q ’5 1,; 4'! .5 E H ‘ 2 o 224'?) f '3 ”Fun IE: '14 0 L1" C: C: .53 03 I c) 51m .4 ednrd \\ 5 «(I (DA H 040.) C6 >94 94 0+3 1, mg: m m m m a. \\ C30.) C10 RS4 :3 H II “C +3 m¥c m -«4 s Q. :3 .‘¢ 0CD “* m" ‘” t." ‘35 a. 3' *1} 33.: no. 3 13 m 2v 4 v :z:<: p...-| a 0 389.5 82.5 26.21 31.45 3,939 3.01 b 10 202.3 82.5 26.21 31.45 2,950 4.02 c 12 275.0 82.5 26.21 31.45 2,758 4.28 d 12 275.0 83.7 35.96 41.20 2,868 4.12 e 20 209.1 83.7 35.96 41.20 2,179 5.42~ f 20 209.1 84.4 '43.26 48.50 2,210 5.35 30 132.6 84.4 43.26 48.50 1,402 8.42 h 35 98.3 84.4 43.26 48.50 1,036 11.41 Horizontal Increment of Flange Stress (Lower Flange) H.I. : y x Af h A21/8 AW Pt(a) a 599.5 25.21 1,000 .-5,950# "92T5 51745 Pt(b) - 292.5 25.21 1,000 = 2,950# 92.5 51.45 Pt(c) : 275.9 25.21 1,000 . 2,759# 92T5 51.45 Pt(d) = 275.0 55.95 1,000 . 2,959# ‘9577 41.20 Pt(e) = 209.1 25.95 1,000 = 2,179# '95—'37 T4 . 2'0 Pt(f) = 209.1 45.25 1,000 = 2,210 ‘9474 49750 Pt(2) = 152.5 45.25 1,000,: 1,402# ’94?4 49.50 - Pt(k) - 99.5 45.25 1,000 = 1,055# 94.4 49.50 10‘. ill-lull 1 IIIvUJI .i I 47 Rivet Pitch of Horizontal Less of Angles (p') Dependent on H.I. 1ust before cutoffs. (HI)' - Point (9) Point (d) Point (f) X only. 1.9., points (9), Ac I h Vc (TIT) X 5.87" l Af plus 1/8 Aw : 1.378# Ac Af V0 V0 Critical Valves of (0') occur (d) & (f) Area of Covers Gross Area - Stress of 1 Cover Plate Rivet (Single Shear) 13,500 x 3.1416 <7/e>2 4 8,100 lb./sq/ in. 48 Will be doubled qivina 10.36" for Min. Use Kin. Spacins 7 x 7/8 = 49 a 6 1/8" Use 6" -8' == End Stiffener Angles Assume 4 angles 6" x 4“ x 3/4" Effective width = 5 1/4 — 1/2 : 4 5/4u (Spec. 452) Bearing Area = 4 x 4 3/4 X 115/16 = 15.4 Sq. In. Pearins Reg- = 599.5 = 14.4 Sq. In. USE 27,000 No. of Rivets = 389.5 = _3 Rivets Use 34 Rivets 11,810 Intermediate Stiffener Ansles (Spec. 433) 60 x 1/2 = 30" less than 84" Use Stiffeners Clear Distance d = 255,000f ( xt )1/:5 3 ( '3 ) f = 1/2" a : 72.5" S = Unit Shear 49 At Support s = 599,500 - 9,270 5,255,000x112 (79279x1/2)m= 55" 84 x 172 9,270 ( Outstandins Lea = Not less than 2 plus (1 x 84) z 5" 30 Thickness = 5/16" Use 3/8" Minimum Ust 2 angles 5" X 3 1/2" X 3/8" 19' from Support 5 = 292.5 = 5950 d. 255,000x1L2 (5950x112)1/3 = 57" T4x17'2 5,950 ( 72.5 ) n 20' from Support 94209.1 =4,970 e.=255,000x1/2 (4,970>:1/2)1/3 = 95.5" 94x172 ( 75.5 ) Greater than 72" Use 72" (Spec. 433) Web Splice (Spec. 430) (Desisn for Shear & Moment) b ‘J- Jr? 3;;- .f (i... ngi‘ Et'éégifsx- . ’3, ~ O?_,_ n , ' 53 :1‘1 :3: .‘ ~* . ‘ _ ‘ M‘. “’1 1 soar-A: '. -... n (:1‘13‘.“ ‘3’ ‘b' ‘ ' . 16¢": F12. 12 Assume Plates and Rivet Rows as shown all clearances 1/8“ (10 plus 10 plus 52 plus 1/8 x 4 = 72.5») Net Cross Section of one pair Splice Plates x c to c distance between-splice plates : 1/8 A, x Eff. Depth Net Area.Required = 5.24 x 84.4 = 7.12 Sq. In. 62.25 51 Assume Rivets placed Opposite Then net width plate = 10" - 3" a 7" Thickness of each plate = 1/2 x 7.12 = .50" Use 1/2" Plate ‘17 No. of Rivets = (Assume no eccentricity as rivets are grouped close together) Strength of 2 plates (t) = 2 x 72 1/2 x 18,000 = 126,000# One Rivet Bearins a 11,910 lb/sq.in. Rivets Req. 126,000 a 11 Rivets 11,810 4 in each of outer rows 3 in inner row Gross section shear plates _ Total Web Area Plate thickness : 1/2 x 84 x 1/2 = .403” 52‘ Use 1K2" Eoment Plates No. Rivets (Use max shear in web) 2 389,5k 52 389,500 : 33 Rivets Use 84 (17 in each row) 11,810 Lateral Bracing (Use Warren tyne) (Unper flanges only) Max Allowance Stress in (C) = 18,000—5 L2 E? C" II Flange width 1.4 I - Length between lateral bracing (Not to exceed 18 feet) Unit Compressive Flanae Stress : Max Noment/Eff. Depth x (Gross Af plus 1/8 Aw) Unit Compressive Flange Stress: 73,000,000 : 15,590 lb/sq in 84.4(55.6§7 15,590 = 18,000 — 5 L2 TI5)2 L2 = 45 (18,000 — 15,590) 1 L = (108,500)? = 550" = 27.5' 53 Use 18' Nin (Spec 438) Use 10 Panels @ 7' = 701 Gross Frames at 14' Wind Loading (Spec 209) (Bridre) Wind load = 1 1/2 x 84 x 50 - El5#/Ft. less than 200 plus 150 = 550#/Ft. use 350#/Ft. (Train)Wind load = 300#/Ft. 650#/Ft. Panel Load : 650 x 7 - 4,550 ! 3. h .21 - ( .r " r A k *A.:_.. .. -... .... . .‘.\ u . _ ~ «A. \ ’3] m“...- V... m -v.m~ Fig”-— *1 3 2‘0 8 ’5. {$3 "’I // 62,] ‘ .‘ \ * .- ,/ \ If?) 1.x .. .57 i ;/ ." ggly/ .i L?. \K' 1"” \\:! / ‘- 1 I ‘ r/ ‘. .4 ', 1. / ,- —.-..._... \‘u/fl—A i..- .._- _' \,.)‘._: .‘ . -., 1 .., -. .. ‘ . _. ... {1’ --, .- _. . I O} b C, d C: I “‘1? I I 4. J 3\ Fig. 13 Unit shear per panel (When all panels to risht loaded) ab = 9 plus 8 plus 7 plus 6 plu us 10 10 10 10 1 plus 4 plus 3 = 45 5 O 10 10 10 54 Stress ab' = 45 x 4,550 x 1.414 - 29,000# 10 b'c : 55 x 4,550 x 1.414 = 25,200# 10 cd' = 28 x 4,550 x 1.414 = 18,050# 10 d'e : 21 x 4,550 x 1.414 = 13,520# 10 . G'f = X 4,550 X 10414 I 9,660# HF‘ 001 Allowable stress (0) : 15,000 - 1/4 L2 52 L (1.41 x 7 x 12) - 18 = 99 in. Try 5 x 3 x 1/2 angle (r - .65) Stress 15,000 - l X 992 = 9,200 1b/sq. in. 4 .552 Area Req : 29,000 = 3.15 sq. in. 9,200 Furnished - 3.75 sq. in. 93 Use throughout Check for tension: (Spec 410) Connect 5" lea 55 Net Section Connected Les : 5 x 1/2 (1,725 x 1 x 1/2) 1 plus SE 2.5 ~ . 862 : sq. in. 49: 1 plus (2.25)2 4 x 1.75 S = Pitch = 2,25" 1 X .725 2 1.725 g = guage = 1 3/4" Net Section unconnected lea = 1/ x 2.5 x 1/2 - .625 31. In. Net area suaplied _ Sum = 2.265 sq. in. Net Area required - 29,007 = 1.61 sq. in (Spec. 310) Qg 18,506 Max stress Developed : 9.200 x 3.75 = 34,500# Rivets needed = 34,500 = 4 Rivets (Single shear) 8,120 ‘ Least (r) for struts = 6 x 12 = .515" 140 Unsupported length - 7'-0"-llO" = 6'-O” (Assumed) Use 3 112" x 3 1/2" x 3/8" angle Panel Load : 4,550# _ 4,550 : 2,275(Taken by each strut) Gross area = 2.48 sq. in. (Easily sufficient) Cross Frames Lateral force = 29,000# Shear in each diagonal : _ 14,500# 29 000 - _L§__ Stress : 14,500 x 1.414 = 20,500# Assume 3 1/2" x 3 1/2" x 3/8“ ansle (r) = (.62) Min (r) Allowable = L L _ 1 2 849 8 1 - , .2 42 2 m / ( plus ) = 60 = .43 -_—_ 60" 140 Allowable stress = 15,000 — 1/4 5,500 - 12,850 lb/sq.in. .62 Area req 3 20,500 a 1.6 sq. in. 12,850 Area supplied = 2.48 sq. in. OK Use 5" x 3 1/2" x 3/8" Throushout Tension Req—net area in tension = 20,500 : 1.14 sq. in. Supplied = 1.52 sq. in. CE Max stress develOped : 1.52 x 18,000 = 27,400# Rivets = 27,400 3 4 Rivets 57 8,120 BILL OF MATERIALS W 91 t No. of Per Total Total Item Pieces Section Foot Ft. Wat. Flange angles 8 6"x§"x2x70'-0" 33.1# 576-0" 19,065.6# 8 Web Plates 4 84"x%"x36'-O" 145.0# 144'-0" 20,592.04 Cover Plates 1 15"x§x72'-0” 38.3# 72'-0" 2,757.6# 4 . l 15"x§x56'~0" 38.3 56'—0" 2,144.8# 4 2 l5"x§x38'—O“ 38.3# 76'-0" 2,910.8# 4 2 15"x9x30'-0" 28.7# 60'-0" 1,722.0# 15 Stiffeners End Ansles End Fillers Int. Ansles Int. Fillers Splice Plates Lateral Bracing Cross Frames (D 56 4 10 6"x4”x§x6'-11“ 4 l4"xe6'-01/4" 8 5"x3%x§x6'-11" 8 3%“xgx6'-0%" 14"x%"x4'-4“ lO"x%"x2'—O" 5"X3"X%"X8'-3" 3%”x3%“x3x5'-7" 20”x7x1'-6" 15 14"xe1'-2" 16 15"x7x3'-3" 15 14"x7xl'-2" 15 23.6# 41.7# 10.4# 10.4# 25.8# 17.0# 12.8# 8.5# 29.8# 20.8# 20.3% 20.8# 58 llO'-8" 2,511.1# 48'-2" 2,008.7# 387'-4" 4,028.2# 5571-2" 3,606.6# 17'-4" 412.5# 15'—0" 272.0# 82'v6" 1,055.8# 27'—11" 257.5# 5'—0" 89.4# 2'-4" 48.5# 29'—1" 552.5# 10'-6" 218.4% End Frames 4 5"x3%"x3x7'-5" 10.4# 29'-8” 308.3# 4 5"x5§"x5x5'—5" 10.44 25'-8" 255.34 8 8 19"xel’-7" 28.3# 10'—8" 557.8# 15 2 10"x3x10“ l2.8# l'.8" 21.0# 8 Int. Frames 8 3%"x3%"x§x6'5" 8.5# 51'4" 455.5# 8 8 31”x31"x3x8'-2" 8.5# 55's4" 555.9# 8 15 15Hx§x1'—5" 19.1# 20'_0" 382.0# 8 8 9"x3x9" 11.5# 5'—0" 59.04 8 Rivet Heads 8200 18# per 100 = 1,476.0# Total 67,205.8# VI DECK PLATE GIRDER R.R. BRIDGE WELDED STEEL) Data and Specifications Single Track Span : 70'_0" Loadins Coooer E-72 Working Stresses Flexure 20,000#/sq." Where flanoes are supported lateral]v 60 Shear in throat. Fillet Welds 13,600"/Sq." Specifications American Institute of Steel Construction American Welding Society Desisn of Web and Stiffeners Depth of girder = 1 x 70 x 12 = 84" TU Assume dead load = 20% less than for riveted case. KAX SHEARS IN 1,000 LB. Distance fm. Support in Ft. 0 10 20 30 35 4 0 Dead Load in Kips 29.0 20 12 Live Load in Kips 199.1 150.1 109.0 71.7 55.3 Impact 155.4 117.2 85.1 55.9 43.0 Total Kips 383.5 287.3 205.1151.5 98.5 MAX KOXENTS IN KIP FEET Dist. fm. Support in Ft. 10 20 30 35 Dead Load 240 400 480 490 Live Lord 1,554 2,528 3,006 3,073 Impace 1,212 1,970 2,344 2,398 Total 3,006 4,898 5,830 5,951 Total in K-in : 36,072 58,800 69,960 72,412 61 End Shear = 383,000# Web Thickness Allowable 15,000 #/Sq." AISC (Spec 10) 383,000 = 0350 84 x 13,000 Kin. Web Thickness : 84 .484 (Spec 42) AISC 178 1 Use 5“ web Unit Web Shear = 583,000 : 9 130 S .u - 521—37170 ’#/q A: Need for Stiffeners: If E : or greater than 70 Intermediate stiffeners are t required wherever h exceeds 8000/(Ss)8 t MH 1 l ' - Near the Reaction Point 8,000/(sq)5 - 8,000/(9130) 83.7“ (Spec. 45) Value of h/t : E20 : 168 Stiffeners Needed .5 §33)1/3 (Spec. 45) Stiffener Spacing : d -- 270,000t ( (h) 8s = 270,000 x .5 (9150) 9150 ( 168) There will be 14 stiffeners spaced at 56" throughout lensth 0f Span. 62 Stiffener Plates - 84 - 7' 12 Good practice is to make stiffener width in inches equal to depth in feet (Use 7") t =_l x Width = (Spec l7) . 7 = .583“ 12 I2 Use 7' x 8/16" plates placed in pairs on Opposite sides of web. Strenath of Stiffener Welds Welding Stiffeners to Web Common practice is to use 3/4" rivets on 5" centers. Double bearina strength a 11,200# i" fillet welds = 2,400# per lineal inch Use four welds on two stiffeners - 4 x 2,400 : 9,600# per lineal inch. Equivalent of rivet per 6" = 6/5 x 11,300 3 9,600 1.4" of weld However min. intermittent weld ; 2" Spaced at 5" Use End Stiffeners Reaction transferred to web : 383,000# 63 Stiffeners act as column whose heisht = % web depth : 1/2 X 84:" = 4.2" This is stiff short column Allowable = 17,000 lb. per sq. in. 17,000 Use two pair of end stiffeners each to take 2/3 of total load as one will probably receive more than 1/2 total reaction. 2/5 x 22.5 = 15.0 sq. in. One plate = 7.0 sq. in. Use 8" x 7/8" Stiffeners (2 Pairs) Kin : 6" on centers Welding and stiffeners Reaction transferred per pair of stiffeners - 2/5 x 585,000 = 255,000# Length 1/4" weld required : 265,000 = 107" ' 2,400 64 107" : 27“ in 84“ of web 4 Use 9 3" welds : 27" Check intermediate stiffeners for max concentration load. Max load = 72,000# plus 72,000 x .78 3 72,000 plus ‘56,000 = 121,000# 128,000 : 7.53 Sq. In. Needed 1:,‘5v’j 7 x 9/16 a 7.88 Sq. In. Supplied 0K Desisn of fiance (with lateral support) Nax moment - 71,412,000 in.# Aoproximate eff. depth = 54" plus 1" = 85" Flange area required = 71,412,000 - 46.7 Sq. In. 18,000 x 85 Effective area of web 1/6 x 1/2 x 84 = 7.0 Sq. In. Area in flanse plates ; 46.7 - 7 = 39.7 Sq. In. Flange section: Use 1 - 20" x 7/8" 0) Us l _ 18“ X 5/4" 1 — 16" x 5/8" Gross moment of inertia Web = 1/2 x 1/2 x 543 - 24,700 in. 4 20 x 7/8" plates = 2 x 17.50 x 42.442 = 63,000 in. 4 18 x 5/1" plates 2 x 15.50 x 157252 - 50,500 in. 4 16 x 5/8" plates 2 x 10.00 x 43.9375 = 38,600 Total I 175,900 in. 4 True fiber str_ss = 71,412,000 x 44.250 = 17,830 Lb. Per 176,900 Sq. In. C: m m Cut off covers Net I of web plus 20" x 7/8" plus 18" x 2/4" p1ates - 138,000 1n.4 Allowable moment = 18,000 1 8,300 = 57,000,000 In.# '2 L/ ('3 L. x 43, a m Bending moment at 18' point - 54,800,000 in.# . Cut off tOp plate. 87,700 in. 1b. Net I of web plus 20" x 7/8" plate 36,800,000 in.# Allowable moment : 87,700 x 18,000 42,875 Moment at 10' point : 36,072,000 in.# Cut off 18“ X 3/4" plate at this point. Flanse Welds Weld between web and flange (41.00 x 43.1) . 3,830# per lineal inch 88 = 19 = 383,000 I 1757805 5 - 17.50 x 42.44 plus 15.50 x 45.25 plus 10.00 x 45.9575 — 41.00 = 43.1" : 743 plus 585 plus 439 = 1,767 41.00 41 A 7/16“ filLet weld gives a value of 4,200# per lineal in. .4375 X .707 X 13,600 _ Weld between flange plate and first cover 67 S8 3 v0 = 585,000 x (25.50 x 45.5) - 2200 # per inch. ‘I 175,900 a 3/8" intermittent weld 2“ long snaced at 4" in the clear produces shear : 2,600# per inch. Weld between inner and outer cover plates 88 - 585,000 x (10.00 x 45.9575) = 9504 per in. 175,900 Use Minimum 1/4" intermittent weld 2" long spaced 4" in clear. Check web splice Fibre stress in web a 42 x 19,600 . 18,600# per 44. 25 Sq. in. Tensile value of plate = 1/2 x 18,600 - 9,300# per in. Tensile value of 1/2" butt weld = 1/2 x 13.00 = 6,500# per inch. Total = 2,850# per inch. Area reinforced plates .438 Reinforced plate area a 2,850 Original plate area 6,500 Area needed - .438 x 12 x 1/2 _ 2.63 Sq. In. per foot. 68 at 12" below top of web Fibre stress = 30 x 19,600 : 13,300# per inch. he. Use two 6" x 1/4" plates Area supplied : 3.00 Sq. inches Weld on reinforcina plate Use 1/4" fillets weld shear a 2,000# per in. Weld length = 2.850 x 12 . 8.55" 2 x 2000 Use 8" min plate to equalize butt weld Plates . 2 - 8" x 6" x 1/4" Lateral bracing (use Warren type) (Upper flange only) Max allowable stress in (c) = 18,000 - 5 13 b2 (3' II Flanae width 1...: ll length between lateral bracing Not to exceed Unit (c) flange stress : Max moment Eff depth (Af plus % Am): 69 71,412,000 = 17,400# per sq. inch 85 (48.00) 17,400 = 18,000 - 5 12 (8072 12 = 80 (18,000 _ 17,400) 1 219" = 18 plus feet Use 18' Use same bracing as in riveted truss Diagonals . 5" x3" x 1/2“ angles Max stress develOped = 9,200 x 3.75 a 34,500# lé" fillet weld - 5000# per lineal inch 34,500 = 7" Use 3.5" on each side 5,000 Struts: 3%" x 3%" x 3" angles 15,000 — 1/4 x (54)2) o 0 Stress 15,000 - 910 14,090# per sq. in. 3/8" welds - 3750 per lineal inch 35,000 = 903" Use 4.5" on each side. Use 9'I of weld per intermediate frames. End Frames: 5.05 x 14,000 42,029 = 11. 3,750 # 0F ITEI PIECES Flange Plates 4 4 4 Web Plates 4 End Stiffeners 16 Int Stiffeners 56 Splice Plates 4 Lateral Bracing 10 5 End Frames 4 4 8 _ 42,000# Use 11" BILL OF EATERIALS SE TION c l6"x5/8"x 5o'—0'I l8"x3/4"x 48'—0" 20”x7/8"x 721_ou 84'x%"x36' ~0” 8”x7/8"x7' ~0" 7"x9/l6x7' _Qn 6"X%"X8” 5”x3"x%"x 9|_6H ’ 1 i 3§”X3§"X 3/8"X6'-2" 5"x3%"x3/8" x7'_5" 5"x3%"x3/8" x6'_5“ l9"x7/l6”x 11_7u 59.5# 145.0# 23.8# 13.4# 5.1# 12.8# 8.5# 10.4# 10.4# 1.5 on each side. TOTAL l20'-0" 192'—0" 144'—o"0 112'-0" 392'-0" 2!_Oll Q5 I_Oll 70 T CTAL WEIGHT 4,080.0# 8,812.8# 17,136.0# 20,592.0# Int Frames 8 Welds 10"x7/8"X10u 3%"x3%"x5/8" X6'-5" 3%"x3%”x3/8" x8'—2” 15"X3/8"x1'-3u 12.8# 1'-8" 8-5# 51'—4" 8.5# 651_4u 19.1# 2U'_OH 11.5# 6'_O" Total Weight 21.0# 455.54 L0 01 ()1 . 4 82.0# 03 59.0# 168.0# 52,594.5# 71 72 VII DECK PLATE GIRDER RAILROAD BRIDGE (ALUKINUM) DATA AND SPECIFICATIONS Single Track Span = 70'.-0'I According to American Railroad Enaineerina Association “Specifications for Steel Railways Bridges, 1941, as "Sup- plemented by "Specifications for the Design and Fabrication of Structures of Alcoa Aluminum Alloy" 615-t." As revised September 15, 1947. As the dead load stresses are 10% or less of the total and the weight of aluminum spans rum about 40% of corresponding sfieel the shears and moments will be con— sidered as the same as for the steel spans which is on the safe side. Because the live load deflection of aluminum is greater than that for steel and because the web depths for steel are arbitrarily chosen the depth of webs for aluminum will be chosen one foot greater than that for steel. This will change the weight only a small amount. Assume: Flange angles 2 8" x6" x 5/8" 2 Plates = 14" x 5/8" 73 1 Plates = 14' x 4' 11:80" Assume t 3/4' ‘% - less than 160 Use Horizontal Stiffener SE = 16,000 pounds per sq. in. (See Specs,) F12. 14 Try: 3/4“ Web 2-14' x 5/8' Plates 1-14' x 1/2“ Plate I" 5‘. . 5a: 74 2-6“ x 8" x7/8“ Anales 5/4 x (95)3 plus 2 (14x(l.75)3 p1us 24.5 x (48.875)2 12 12 plus 4(72.5 plus 11.48 (45.59)2 ) 55,300 plus 117,500 plus 300 plus 94,600 257,700 ln.4 75,000,000 x 49.75 = 15,500# 267,700 73,000,000 in.-16(See riveted girder) 16,000# per sq. in. (Figure 5A of Specifications) Check against sidewise buckling (Figure 2, Page 12, Speci- fications) 11 = Mament of Inertia for beam about principal axis parallel to web. I _ 96 x (3/4)3 plus 2 (1.75 x 145) plus 4 (54.9 plus 12 12 ' 11.48 (1.985)2) : 5 plus 800 plus 140 plus 181 z 1124 lnehes4 75 Foment of Inertia for compression flange about axis parallel to web 1/2 11 = 562 inches4 Torsion Factor a Sum of 1/3 bt3 (See Specs) 3/43 plus 4 (8 plus 5.375) x ("F/8)"-5 plus 3 CNN (14 x (1.705) 13.5 plus 11.9 plus 50 85.4 inches3 Section modulus of compression flanse >2) 3/4 § (48)3 plus (14 x 1.75)8 plus 24.5 x (48.875 5 5 plus 2(72.5 plus 11.48 (45.59)2) 27,700 plus 58,750 plus 150 plus 47,300 135,900 inches4 155,900 = 2,590 inchess “49775‘ L : Laterally unsupported length of compression flqnse i inches Assume L = 10' = 168" ( I1 (J L-2 plus 23 Ifdg) )2 \J 1011-1 O ( 1124 (85.4 x 120“ plus 25 x 552 x (99.52) 1 ( l44,500,000,000 )5 579,500 C” I II 120 - 10.05 (B7sc)% (579,500)% 11.90 ( ( 2,590 ) sa ; 15,900 1b/sq. in. 95 Horizontal Stiffeners (See Spec. 5) Radius of syration shall not be less than r = Required radius of syration of one stiffener in inches 76 I1 77 h a Clear height of web in inches t = Web thickness f = Compressive stress at toe of flange angles in # (Sq. In.) or” A coefficient which defends upon the ratio of the Spacing of the vertical stiffeners, S, to the clear height of the web, h. (See Table Iv, Specifications) Assume S = h : ; = .875 s 70 H 80 Where S a Stiffener Spacing h : clear depth of web. f = 13,600 X 39 : 11,000 #/Sq. In. 49. 75 _9 r : 6.60 (80) 11,000 X 10 373 = 0825 Try a 3" x 3" x 1/4" angle I _ 1.18 x 1.45 x (82)2 78 1.18 X .96 2.14 1nehes4 )4 - (J ) (1.45) 131" I‘:( ( I A Horizontal stiffeners shall be cut off at the vertical stiffeners and shall be spaced 16.21" below the toe of the tOp flanne angles. a = 1/2 h = §9 = 40" 2 40 x.4 : 16" plus 0.21“ = 16.21" Stiffener Spacing: (Figure 6A (Specifications) Shear on Heb (Gross Section) : 389,500 = 5,400 lb/sq.in. 90 x 374 RHtiO = 80 a 107 p t 574 Use Stiffener Spacing = h = 70" (From Figure 6A) Allowance Sh ar : 6,250 1b/sq. in. Size of Stiffener: When g is greater than 0.4 5‘ Substituting: 79 tph 4% Es)2 plus 0.525 ) Required I of stiffener in inches4 Web thickness in inches Stiffener spacins = 70" Clear height of web = 80" 16 3/43 5‘5 ( 5X T;87574 ((.875)2 plus 0.525 g 11.5 (.755 plus .525) 11.5 (1.590) 16.0 Try Two stiffeners 4" x 3" x 5/16" (0 2 2 1 (5.29 plus 2.09 (1.515)? (3.29 plus 5.45 (8.74) 7.481' (UIE 7/8" COLD DRIVEN) PITCH OF RIVETS IN VERTICAL LEGS OF ANGLES 80 1. I E; .. <11 03 (I) :1 \ ,1 S . '* 11 E. 8,. f ‘5" ‘4 V o ‘H H m A 0.“) C um i |% «A :3 g A .53 “SH €5\ Q—lo '0' 0 H H 31% +3 (DH 0 QJHA ,C: 4:: ('0 ‘2 C4 II 0 06 c: o. hQU h . \. a Sfi cu «a: O: o a) d ID < ms: => . - +4 ¢L\\ mm «0 Q m»: Ski 0* U m .o 4:» cs Lu—l mu) mr-l ll m . 03 v .C.‘ l‘ C +38 (UV 0 UJr-l 03 Q. o o \ P\ 0 fi" q-l COO (D ‘H Obi 0 C" H .1. 74.0 II P a. 0 If!“ ,C. a 'H Lug “-1 $4 Hm o H (DI—l H HN D-c 0&1 CD> [fl (5 <1: (54" :11 v >V (I: 04 H a 0 3895 94.4 42.22 51.22 3460 2025 3990 3.12 b 10 292J394.4 42.22 51.22 2560 2025 3260 3.82 c 20 209J.94.4 42.22 51.22 1830 2025 2725 4.50 d 30 132J594.4 42.22 51.22 1160 2025 2350 5.30 e 35 98394.4 42.22 51.22 860 2025 2180 5.70 47.2 x 2 24.5 plus 22.96 1200 plus 1040 47.2 94.4 47.46 (UBE 7/8" COLD DRIVEN) PITCH OF RIVETS IN VERTICAL LEGS OF ANGLES 80 F;* 1 I .. <23 U1 CD 1 $4 \ A g o. H fl :3 8" f 5 ‘4 V o “Hr-1 m a «(DC “(D film “A :3 o A .5: “SH C3\ 94- '0' 0 H H =# 9 ma . ®r4f\ £1<£C CUE C. u . and C o. $40.6 L. . \ .4 OH 02 «a: on o m ¢ua ¢mm > . A- H m\ cm ~O C.) «IV :SH (3‘ 0" :E: «O P cs LII—1 ma) oar-I u m .m v g5 a p55 my . Hip-1 mg. . \ +3\ 051‘ .fi we a) H on 0 cr F4 .3 AL) II P . 0 «HE .C. .. 'H is H Sat-m) o H 0H H «HN m cm m> m 25¢ wdv m ~I>v m 0”4 8 0 3895 94.4 42.22 51.22 3460 2025 3990 3.12 b 10 292d594.4 42.22 51.22 2560 2025 3260 3.82 c 20 209J.94.4 42.22 51.22 1830 2025 2725 4.50 d 30 132J594.4 42.22 51.22 1160 2025 2350 5.30 e 35 98394.4 42.22 51.22 860 2025 2180 5.70 EFF. DEPTH = 24.5 x 48.875 plus 22.96 x 45.39 47.2 x 2 24.5 plus 22.96 1200 plus 1040 47.2 94.4 47.46 80 PITCH 0F RIVETS IN VERTICAL LEGS 0F ANGLES (UEE 7/8" COLD DRIVEN) F: 1 B .. <fl U1 CD 1’». \ A 0:; as H '1'): v 0 “H m A «(DC «(D i IQ’\ «A :3 o A ,C: QSSSH (:5\ Mo '5' . H H =11: +3 (Dr-l I Git-1" .E'. 42:: CUE: C: II o are! C c. ACLU s. - \ H SH N - Cr: 0:: c) m 1¢ In <:mac >- . . F4 £L‘x gm «0 C) div 23H (3‘ O" :1: «O P m 34H mm wri ll m .m ~¢ .QE~ 2‘. PE cd‘—I o (Ur-1 U] Q. o o \ +3\ Ofl" «H (00 (D 'H 06. O O" H .3 814.0 II P .. O 145-! ,2; a “—1 $4 ‘4 ‘4 94m 0 9" 0H H «HN a. Olin m:> [fl (5 <1: (54v :1; V >4, ,1; ma 8 0 3895 94.4 42.22 51.22 3460 2025 3990 3.12 b 10 292d594.4 42.22 51.22 2560 2025 3260 3.82 c 20 209J.94.4 42.22 51.22 1830 2025 2725 4.50 d 30 132J594.4 42.22 51.22 1160 2025 2350 5.30 e 35 98394.4 42.22 51.22 860 2025 2180 5.70 EFF. DEPTH : 24.5 x 48.875 plus 22.96 x 45.39 24.5 plus 22.96 1200 plus 1049 47.2 x 2 = 47.2 94.4 47.46 81 Horizontal Increment of fiance Stress (Upper Fiance) HI : V x A h Af X_f/8 AW Where HI 2 Horizontal Increment V : Shear at section h = Effective depth Af - Area of flange AW 3 Area of web *0 d SD (A “D L0 01 >4 1 42.22 x 1090 _ 3.460# 94.4 51.22 Pt(b) 292.5 x 8.75 : 2.550# Pt(c) 209.1 x 8.75 = 1850# Pt(d) 152.5 x 8.75 = 11504 Pt(e) 98.5 x 8.75 = 860# Vertical Increment of Flange Stress (Use one heavy driver over 3' plus floor load (Spec 428 Area) W : 598 plus 72,000 x 2 - 25 x 2000 - 2025# 2 x 12 2 x 36 Resultant R.I. Where H.I W Pt(a) Pt(b) 82 Increment of Flange Stress ( (HI)2 x W2 )2 (54502 plus 20252)% Horizontal Increment Vertical load .1. 2 (11,950,000 plus 4,000,525) s (15,950,525)% - 5,970# (uh-4 (25502 plus 20252) (5,550,000 plus 4,000,525)% 1 (10,650,625)2 = 3,260# Ma .._ L’ .1" ”I ‘ u") 0 .y‘ p—..-. to. 4 1......0 0+ C. ... .0 0.5 .3 m . s (0 . Q . I111 . . ) 11:11 1 10. .p .I 1 i1 l1 l .L! I l I. I 000 11.11 1|1.|.l| AN 6.. . 4 - . .11.»! 1r II I IIINI '7" ll '5’: I‘ll. 1 I- c 5 ..| .141 DII 111111.0‘Ill1n 1.. V 1.511 111.! 111‘1IO ... .00 ‘11:. .4 ' \... 1.! IL . . 1. - ., ‘1 t 1.51 1 1.! .1.1 ..I V . 1.3.... a. . 1111 1 1| I .I l I I. 1.1.1.1! ,Iv..11 . .I..1III-I.|¢ . :I .J - . u .31.-. i .1: I. .o. I .I, o 1 1:1 I .1 . m. u? Ital . 1. n O ..l,-.-..:lis-1sl~ 0 k t- “ 1 ~ ~_’.”—._ '“W a . 0T5 Q... 9, J» U U! spa-o 01 X0 . . - 84 Pt(c) (18502 plus 20252)5 = (5,550,000 plus 4,000,525)% (7.550,525)5 = 2,775# Pt(d) (11502 20252)% - (1,550,000 plus 4,000,525)% (5,550,525)% = 2,550# 1.- Pt(e) (8502 plus 20252)? . (740,000 plus 4,000,525)% (4,740,525)% = 2,180# (Use same pitch on bottom Flange) Rivet Pitch of horizontal less or anqles (P'). Dependent on H. I. only. HI 3 V X Ag plus Ac = Area of covers Af 1/8 A W Af - Gross Area P' - 22 To = Stress of 1 cover H.I. Plate Rivet (Single shear) *3 c = 10,000 x 5.14 7/82 = 4 6,030 lb/sq/in 85 94.4 51.22 PI 6030 : 3.06'I 1970 u 0‘; O H 10 c m (D Hm Will be dou bled (Rivet on each side) Check for buckling: E : 46,600 — 384 EL : 46,600 - 384 x .5 x 7 A r 362 = 46,000 — 3,720 - 42.880 Ultimate stresses r - .29 x 1.25 - .362 (Pase 71 Alcoa Structure Handbook) Allowable stress (Specifications) . 17,000 - 100 v 7 .362 = 15,050 ib/sq in Use 15,000 lb/sq in 42,880 = 2.86 = Factor of Safet OK 15,000 I y ‘—_ Use 6" Spacing WGb 591133 (Spec. 430 A.R.E.A.) (Desisn for shear moment) 86 F12. 15 Assume all Clearances : 1/8", Plates and rivet rows as shown. Net cross section of one pair of Splice Plates x c to 0 distance between splice plates - 1/8 Aw x Eff Depth. Net Area Req = 9 x 92.4 = 12.3 sq. in. 67.5 Assume Rivets placed opposite then net width - 12" -3" = 9“ 87 [.4 (0 Thickness of each plate : 5 x .3 - .685 (Use 3/4“ Plate) Number of rivets (Assume no eccentricity) Strength of two plates 3 2 x 9 x 16,000 - 216,000# No. rivets (bearing) - 216,000 a 17.3 a 18 rivets 6 in 12,470 each row Cross Section shear plate =-Web Plate thickness = 1/2 x 96 x 112 = .46 55 Use 1/2" Moment Plates No rivets (Use Max shear in web) . 389.5 Kips 389,500 : 32 Rivets 12,470 Use 32 Rivets 16 in each row. End Stiffeners Assume 4 angles 6" x 4" x 3/4" Effective Wldth : 51/4 - 1/2 - 4 3/4u 88 ()3 Bearina area 4 x 4 3/4 x l = 15.4 sq. in. ""l O) Bearing Req. - 389,500 . 14.4 sq. in. 27,000 Number of rivets = 389.5 _ 31.2 Use 32 rivets 12,470 I Lateral Bracing Use 7 panela @ 10' = 70' Wind Loading (A.R.E.A. Spec. 209) Brides = 1 s x 95 x 59 - 452 1b/ft. greater than 550 lb/ft Train = 300 1b/ft. Top Bracing Train - 300 #/1 Bridge: 215 #/1 515 4/1 515 #/1 x 10' s 5,150# (Use Warren type bracing) 89 F12. 16 Unit shear per panel (When all panels to right loaded) Q plus g plus _ 7 7 xii-P. "d H C (1) Stress ab' = 5 x 5160 x 1.75 = 27,100# Allowable stress (0) = 17,000 - 100 and 1 = (12.2 x 12) - so" a 116.5“ Try Two 3 %" x 3 %" x 3/8" angles r _ 1.07" Sa = 17,000 - 100 11605 I 6,000# 1.06 Area Required .— 27,100 = 405 Sq. in. 6,000 Area Supplied 4.96 sq. in. Qg Use throughout 90 Check for Tension (Spec. 410 Area) Net Area Required = 27,100 = 1.69 sq. in. 16,000 Net Section Connected lees = 2 (5 e x e - (1.725 X 1 x %) : 305 - 0862 = 2064: SOL. in. OK Max Stress Develoned = 6,000 x 4.96 a 29,800# Rivets Needed = 29,800 a 6 Rivets (Single Shear) ’62240 (3 in each lee) Least r for struts (6 x 12—4 = .68 OK 100 Use 3/12" x 3/12" x 3/8" Panel Load - 5,160# 5,160 2 2,580 Taken by Strut Gross Area - 2.49 sq. in. 93 Bottom Bracing (Use Warren type) 91 Struts Use 3" x 3" x 7/8" Panel Load a 10 x 216 = 2,160# Stress in a b' : 3 x 2,160 X 1.75 - 11,300# 1 = 11605" Try 2 3" x 3" X 3/8" r .91 Sa - 17,000 _ 100 116.5 = 4,200 lb/sq.1n. "". ‘91" Area Required _ 11,300 = 2.69 sq. in. 4,200 Area Supplied 4. 22 sq. in. 91$- Tension less than 1 sq. in. 95 Stress Developed a 4,200 x 4.22 = 17,700# Rivets Needed 3 17,700 = 2.9 Use 4 Rivets 6,240 Cross Frames Intermediate Cross Frames - Use 3" x 5" x 3/8" angles 92 End Frames Lateral Force - 27,700# Shear in Back Diagonal = 27,700 — 11,300 a 8,200# 2 Stress in Back Diagonal = 8,200 x 10.6 = 12,400# __7_ Assume 3 %“ x 3 s" x 3.8" anvles r - (.62) Use 5" x 3 5" x 3/9" angles Min (r) Allowable = 1 = 52 = (52) OK 100 100 ‘— 1 : 5 x 10.5 x 12 — 12 = 52" N) Use Rivets a 6,240 x 2 = 12,480# ITEfi Flange Ansles Web Ansles Cover P1ates Cover Plates End Stiffeners End Stif- feners Fill Hor Stiffener Int. Stiffener Splice Plates Splice Plates Lateral Bracing # OF PIECES 16 12 44 (I) 28 16 (A l‘ D BILL OF SECTION 8"x6”x5/8"X 72I_OH 96"x3/4"x 55'_0" 14"X4/8"x72' -0" 14"x§”x 721-0" 6"x4”x3/4"x 7'_10N 10“x5/8"x6' -8" 5Hx5":&"x 5I_7u 4"x3"x5/16”x 7'—1o" 12Hx5/4HX ll_6l| l4"x%"x 4...?“ 5%"x5eux3/e" x9'85“ 1 ml 32‘ " X015 II X 5/snx5'—e" 3"x3"X3/8"x l 9!_g§n 3"x3"x3/8"x 51_8H 15"X7/16"X 3|_5u l4"x7/l6"x 1'2" HATERIALS WGT/FT 9.84# 87.12% 10.59# 10.89# 8.47# 3.01# 3.01# 9.941# 7.411 3 ram fit} t1] :1 F19 560.0" 140.'0" 280.'O" 125'-4” 53!_4II 671_OH 344'-8" 12'-O" 1s'-4" 271l_0fl 90'-e" 271'-l0" 90l_8" 82'-O" 37I_4u TOTAL v}, E I 3H T 5, 0 k) 1. 667.8# 439.4# 051.5# 403.5# 115.9# 572.0# 150.7# 155.3# 818.2% 272.9# 693.2# 32 End Frames Int.Frames RiVet Heads 8600 14”x7/l6"x 1'! 2H 5"x3 ~ 'x3/8" x8'- 0” w33" 15"X3/8"x ll_3u 9 "XSI/e "X9 II SHXPZHX B/eflx 8'-43" l5”x3/8"X ll_3fl 9"X3/8"X9" 7.411# 3.69# 9 O) (D (D a d) 0) 3 m_ 2. (fl 5# 6.806# 4.084# 7.5#/100 Total _4u 33|_2n 10'-O" ll_6u 100'-6" souou 4l_6fl 94 276.7# 204.2# 18.4# 65330 6# 34,365.0# 95 VII WCODEN GIRDER RAILROAD BRIDGE Data and Suecificaticns Single track Span = 70'-O" Depth: 6'-0" Limit LOfidinQ : Cooper E-72 Walking Stress Flexure - 3,000 p.s.i. Moment : 70,000,000 inch pounds Shear = 380,000 pounds Try 4 - 11" X 56 7/8" glued laminated woods girders. 72'-8" long 0'.) I 0 HI' " 70,000,000 X 28.4375 4 X 11 x (56.8757U 12 2900 p.s.i. OK This would require 8 girders of this size which is im- practical. APPENDIXES I. SPECIFICATIONS for the DESIGN AND FABRICATION of STRUCTURES of ALCOA ALUMINUM ALLOY 6lS—T Aluminum Company of America New Kensinaton, Penna. Revised- September 15, 1947 11 These specifications are intended to supplement stan- dard specifications prescribed for the desisn of steel structures. Nothina in these soecifications is to be con— strued as permitting any radical departure from accepted good design practice. These specifications are comparable to those standard specifications for ordinary srade carbon steel structures in which the basic tensile design stress is 18,000 p.s.i. Alcoa aluminum alloy 6lS-T is a heat-treated material and has the following nominal chemical composition: Al Cu Si Ms Cr 97.9% 0.25% 0.62 1.0% 0.25% The following are the typical physical prOperties of 61S—T alloy: Weight per cubic inch 0.098 lb. Tensile strength 45,000 psi. Tensile yield strength (0.2 percent set) 40,000 psi. Elongation in 2 in. (1/2-in. Diameter round specimen) 17 percent Compressive yield strength (0.2 percent set) 40,000 psi. Ultimate shear strength 30,000 psi. Shear yield strength (0.2 percent set) 26,000 psi. Ultimate bearina strength (edse distance = twice rivet diameter) 94,000 psi. Modulus of elasticity in tension and com- pression 10,000,000 psi. Modulus of elasticity in shear 3,800,000 psi. Poisson's ratio 0.33 ill Brinell hardness, 500 ks load, 10 mm ball 95 Coefficient of eXpansion per 10 F 0.000013 The following material specifications apply to this alloy: Sheet and plate: Navy 47—A—l2b, Federal QQ-A—327 Tubina: Navy 44-T-30b, Federal WW—T—789 Shapes: Navy 46-A—lOd, Federal QQ—A—325 Alloy 6lS—T is produced in the form of sheet, plate, extruded shapes, rolled shapes, tubing, rod, bar, wire, and rivets. It combines good strength characteristics with the best cold workability of any of the heat-treated aluminum alloys. Because of its excellent resistance to corrosion, it is widely used in marine structures and in other locations where conditions of eXposure are severe. Reference: Alcoa Structural Handbook; Aluminum Research Laboratories Technical Paper No. 1, Column Strength of Various Aluminum Alloys". 1. Allowable Unit Stresses: Axial tension, net section 16,000 psi. Tension in extreme fibers of rolled shapes, extruded shapes, girders, and built sections sublected to bending 16,000 psi. Stress in extreme fibers of pins 24,000 psi. Shear in power-driven rivets, cold-driven 6lS—T 10,000 psi. Shear in power-driven rivets, hot-driven 538 (1030 to 10500F) 8,000 psi. Shear in pins and in turned bolts 10,000 psi. I3earins on pins 24,000 psi. iv Bearing on power-driven rivets, turned bolts in reamed holes, milled stiffeners, and other parts in contact 27,000 psi Bearing on unfinished bolts 18,000 psi 2. Allowable Compressive Stresses in Columns: For columns centrically loaded the allowable compres- sive stress on the gross section shall be found using the following formulas: For L less than or equal to 100 P - 17,000 — 100 L but r A r For L dreater.than 100 not to excéed 15,000 psi 1.. U P A : 70,000,000 L (pe Where L = greatest slenderness ratio of member. r These column formulas are based on partial fixation of ends. (K a 0.75). A plot of these column formulas is given in Fig. 1, pase xiii. 3. Allowable Compressive Stresses in Flanges of Beams: The compressive stress in the extreme fiber of rolled shapes, extruded shapes, and single-web girders and built sections, subiect to bending, gross section, shall not ex- ceed the values given by the curve in the attached Fin. 8, page xiv. ’4 Values of torsion factor, J to be used in connection with Fig. 2 are given in the Alcoa Structural Handbook for many standard shapes. Values for plates and shapes not shown may be calculated by assumins the sections to be com- posed of rectangles and taking the sum of the terms L bt3 3 for each rectansle where b equals the lensth and t the thickness of the rectangle. The value of J for a built member is the sum of the individual J values of the sections of which it is composed. The term (3 )% used in Fla. 2 is rarely less than one- half width of thg)compression flange for a plate girder. This fact is useful in preliminary design. Double-web box girders, because of their tube-like cross section, are very much stiffer in torsion than single- web girders of comparable size. For the depth-width ratios ordinarily encountered is desisn, double-web box sirders are so stiff in torsion that lateral bucklins failures of the compression flange are of no importance in structural design, and therefore it is not necessary to make any re- duction in allowable stress because of the slenderness ratio or length-width ratio of the flanse. The allowable stress on the compression flange of such members is usually restricted by the possibility of local bucklins of the compression cover plate. 4. Allowable Compressive Stresses for Flat Plates, Less, Webs and Flanges: The compressive stress on the arose area of flat plates, legs and flanges shall not exceed the values aiven by the curves in the attached Fla. 3, page xv, and Fla. 4, page xvi. The compressive stress at the toes of the flange angles in the web of a girder or built member sub‘ect to bendins, gross section, shall not exceed the values siven vii by the curve in Fla. 5. 5. Size of Horizontal stiffeners on the Webs of Plate Girders: A horizontal stiffener of the type covered by Fis. 5A shall have a radius of syration not less than that given by the followins formula: r a or (g)2 r 10-9 t r : required radius of syration of one stiffener in in., h : clear height of web in in., t : web thickness in in., f = compressive stress at toe of flange anales in psi, Cr : a coefficient which depends upon the ratio of the spacing of the vertical stiffeners, s, to the clear heisht of the web, h. Values of or are aiven in Table IV, pass 10. For a stiffener composed of equal size members on both sides of the web, the radius of syration shall be taken about the center line of the web. For a stiffener composed of a member on one side only, the radius of syraticn shall be taken about the face of the web in contact with the stiffener. 6. Allowable Shear Stresses for Flat Plates and Webs: -"\'. The shear stress on flat webs shall not exceed the v6 values given by the curve in the attached Fla. 6, pass xx. The values in Fla. 6 apply to the gross area of the web, but the shear on the net area shall not exceed 12,000 psi. 1‘ vii: 7. Spacinq of Vertical Stiffeners on the Webs of Plate Girders The distance between vertical stiffeners applied to the web of a plate sirder to resist shear bucklins of the web shall not exceed the value indicated by Fis. 6A, pasexxi. Fig. 6A is merely a replot of the data in Fifi. 6 rearranged for convenience in establishing stiffener spacings. Where a stiffener is composed of a pair of members, one on each side of the web only, the distance 5 shall be the distance measured from the rivet line. In determining the spacing of vertical stiffeners to resist shear bucklins in panels containing a horizontal stiffener located as shown in Fla. 5A, the distance h in Fis. 6A may be taken as 90 percent of the clear distance between flanges. 8. Size of Vertical Stiffeners on the Webs of Plate Girde rs: Stiffeners applied to plate sirder webs to resist shear bucklina shall have a moment of inertia, IS, not less than siven by the following formulas: when s less than or equal to 100. 0.4, IS 6.15t3h when greater than 0.4, IS = t3h ( (%)2 plus0.625 ) s h 5(fi) Is = required moment of inertia of stiffener in in.4, t = thickness of web in in., S = required stiffener spacing from Fla. 6A in in., h = clear heiaht of web in in. viii For a stiffener composed of equal size members on both sides of the web, the moment of inertia shall be taken about the center line of the web. For a stiffener composed of a member on one side only, the moment of inertia shall be taken about the face of the web in contact with the stiffener. In determinina moment of inertia of stiffeners the term "h" shall always be taken as the full height between flanges regardless of whether or not a horizontal stiffener is present. 9. Reversal of Stress: Members subiect to reversal of stress under the passage of the live load shall be preportioned as follows: Determine the tensile stress and the compressive stress and increase each by 50 percent of the smaller; then pro- portion the member so that it will be caosble of resistina either increased stress. The connections shall be propor- tioned for the sum of the stresses. 10. Allowable Loads for Rivets and Bolts: The allowable loads on cold-driven 6lS-T rivets are given in the attached Table I, have , and those for hot- driven 538 rivets in the attached T his II, pasexi The allow- able loads on unfinished 2&S-T belts are siven in the attached table ITI, page . These allowable loads are computed on the basis of the allowable shear and bearins stresses siven in Paraqraoh l and represent in each case the contrOllinq value, shear or bearing, whichever is lower. In computing the shear values, ix a correction was applied where necessary to take into accoumt the reduction resulting from the cuttinq action of thin plates. (See Table 3, "Rivetina Alcoa Aluminum" - 1946). All rivet valties are based on the bolt diameters. hoonm an mpmzpo Ham .ucdmmmn an oompm>om mosaob omens * omm oh oaao --- -u- --a --- --- --- -u- --- .fl ”Nu omm oH oflo o3 NH oamo ...... 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N\o new J S oNN mH ooHs oam oH ownm osos omon oHam oooN :. :. oH\o cos ooo mH ooHo oHo oH oowo ooos omon ono oooN oaom oooH N\H wgw tooo NH ooHo ooo o oamo omen omom oHoo oosN ooom oosH oH\s a soon oH ooHo *oam o oomo onus omom ooNo oooN ovom oosH Nan w I no mo mo ulmw no mo mo mm Nansen no mHmon pm>Hm - q oNHm oH\H H ¢o\oo Nm\oN on\HN Nm\oH HHHgo can“ moo.H NNo.o Hmo.o ooo.o Hmo.o pmposto wHom cud H N\s «\m N\o N\H nmposmHo I pm>Hm mocSOQ CH cm>Ha momoa mHDmBOHH¢ *tmmmbaobmem Hmo ooo.oN - moHpmom Hmo ooo.N ammmm Bumfio 2H mem>Hm mam zm>Hmmleom mom Bm>Hm mam Q¢OA szmmm HAm¢EOA44 HH mqmda. TABLE IV VALUES OF STIFFENER COEFFICIENT Cr 0F HORIZONTAL STIFFEMERS FOR WEBB OF PLATE GIRDERS REINFORCED BY ONE HORIZONTAL STIFFENER X11 Values of Coefficient Cr for Various Web Thicknesses s/h 5/8" '1/2" 5/su 314" 0.60 2.16 3.16 4.19 5.28 0.65 2.29 3.35 4.43 ,5.57 0.70 2.42 3.53 4.66 5.83 0.75 2.55 3.71 4.89 6.08 0.80 2.68 3.89 ,5°ll 6.32 0.85 2.80 4.07 5.32 6.55 0.90 2.92 4.24 5.55 6.76 0.95 3.04 4.40 5.71 6.96 1.00 3.15 4.55 5.90 7.15 1.05 3.26 4.69 6.08 7.33 1.10 3.36 4.83 6.25 7.51 1.15 3.46 4.96 6.41 7.68 1.20 o.56 5.09 6.56 7.85 xiii l . I. M - 9 v.“ wants. M F _. s. . m /.x ”If. :~ .n ~ if, I Luv q I. “1.. n 1;. r66 . 1.... .,_ . M , .4; f 4) 5:! C. a: raw; I” t. s. / . _ 0 - - a 6.6.. .66..........:... -II.6--....66.6..6:. 3 36:6! 6:... 6..-.-.66631161- . . . ,6 o .3 so mo we .00 :6 E6 . 90 am...» . , . v \ mom” .mezmumm .9510 to a H .. . I x.) .. s _. . .\-o/ . .6 u 13 \D .... ....v....u..... ...,.. .3.“ 003... To)... m...» 74....” w WWWWWU +0.... 3...... 10):! 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Details in which the fabrication of aluminum alloy 6lS-T differs from that of structural steel are covered by the following specifications: A. Laying Out l. HOle centers may be center punched and cut-off lines may be center punched or scribed. Center punching and scribing shall not be used where such marks would remain on fabricated material. 2. A temperature correction shall be apolied where neces- sary in the layout of critical dimensions. The coefficient of eXpansion shall be taken as 0.000013 per degree Fahrenheit. B. Cutting 1. Material l/2 inch thick or less may be sheared, sawed or out with a router. Material over 1/2 inch thick shall be sawed or routed. 2. Cut edges shall be true and smooth and free from ex- cessive burrs or raared breaks. 3. Edaes of plates carryina calculated stresses shall be planed to a depth of l/4 inch except in the case of sawed or routed edges of a quality equivalent to a planned edge. 4. Reentrant cuts shall be filleted by drilling nrior to cutting. ()1 . Flame cutting of aluminum alloys is not permitted. xxiii C. Heating 1. Structural material shall not be heated except: a. Haterial may be heated to a temnerature not exceedina 400 degrees Fahrenheit for a period not exceedins 15 minutes to facilitate bendinv. b. Rivets shall be heated as soecified in Section D. Punching, Drilling and Beaming 1. Rivet or belt holes in main members shall be sub— punched or subdrilled 3/16 inch smaller than the nominal diameter of the fastener and reamed to finished size after assembly, except that if the metal thickness is greater than the diameter of the hOJe that hole shall be drilled. 2. Rivet or bolt holes in secondary material not car y— ina calculated stress may be punched or drilled to finished size before assembly. 3. The finished diameter of holes for cOld driven rivets shall be not more than 4 percent greater than the nominal diameter of the rivet. 4. The fini-hed diameter of holes for hot driven rivets shall be not more than 7 percent greater than the nominal diameter of the fastener. . The finished diameter of hOleS for unfinished bolts ()1 shall be not more than 1/16" larger than the nominal bOlt diameter. 6. Holes for turned bolts shall be drilled or reamed to give a drivina fit. 1 xxiv 7. All holes shall be cylindrical and perpendicular to the principal surf ce. Holes shall not be drifted in such a manner as to distort the metal. Any chips lodged between contacting surfaces shall be.removed before riveting. E. Rivetina l. The driven head of aluminum alloy rivets preferably shall be of the flat or of the low cone type. a. Flat heads shall have a diameter not less than 1.4 times the nominal rivet diameter and a height not less than 0.4 times the nominal rivet diameter. b. Low cone heads shall have a diameter not less than 1.4 times the nominal rivet diameter and a height, to the apex of the cone, not less than 0.55 times the nominal rivet diameter. The included ansle at the apex of the cone shall be approximately 127 degrees. 2. Rivets shall be driven hot or cold as called for on the plans.' a. Hot driven rivets shall be heated in a hot air type furnace providina uniform temperatures throughout the rivet chamber and equiined wit? automatic temperature controls. b. For hot driven alloy 535 rivets the rivet tem- perature shall be held at 1030 to 1050 degrees Fahrenheit for not less than 15 minutes and not more than one hour before driving. ‘ 0. Hot rivets shall be transferred from the furnace to the work and driven with a minimum loss of time. 3. Rivets shall be driven with direct-acting riveters where practicable. 4. Rivets shall fill the holes completely. Rivet heads shall be concentric with the rivet holes and shall be in proper contact with the surface of the metal. 5. Defective rivets shall be removed by drilling. F. Welding 1. Welding of aluminum alloys is not permitted except as specifically called for on the plans. 2. Where Welding is employed, care shall be exercise d to remove all traces of welding flux. G. Cleaning of Metal Surfaces l. Surfaces of metal shall be cleaned immediately before painting by a method which will remove all dirt, oil, grease, and other foreign substances. 2. Either of the two followins methods of cleaning may be used on exposed metal surfaces: a. Sandblasting - Standard mild sandblasting methods may be used. b. Chemical cleaning - Parts may be immersed in, or swabbed with a dilute water solution of phosporic acid and organic solvents such as Deoxidine No. 126. The solution temperature shall remain in contact with the metal not less than 5 minutes. Residual solution shall be removed with~clear water. xxvi 3. For contactins surfaces only, the metal may be cleaned in accordance with section G—2, or with a s0lvent such as mineral spirits or benzine. 4. Flame cleanins is not permitted. H. Paintina 1. Metal parts shall be painted unless the plans state that no painting is required. 2. Contacting metal surfaces shall be painted before assembly with one coat of zinc chromate primer in accordan ce with Navy Department 39801f10ot10n 52P18 or equivalent, or with one coat of Alumilastic (brushing consistency with zinc chromate added) or equivalent. Zinc chromate paint shall be allowed to dry before asserbly of the parts. 3. In any case where aluminum work is to be fastened to steel members or other dissimilar metal parts, the alum- inum shall be kept from diredt contact with such parts by paintins the aluminum surface as described in H-2 and by painting the dissimilar metal with a suitable primer paint. 4. Aluminum surfaces to be placed in contact with concrete or masonry construction shall, before installation, be given a heavy coat of an Alkali resistant bituminous paint. The quality of the bituminous paint used shall be equal to that called for in the army-navy aeronautical specification AN-P-Zl. The paint shall be applied as it is received from the manufacturer without the addition of any thinner. xxvii '- o. All other surfaces shall be given one shOp coat of zinc chromate primer in accordance with Iavy Department Specification 52PlS or equivalent. 6. All surfaces, except those covered by sections h—2, H—3 and H—4 shall be siven a second shop coat of paint C‘f consistina of two pounds of Alcoa Albron Standard Pas e No. 205 per gallon of varnish to Federal Specification TTVSlA, or equivalent. Sufficient Prussian Blue shall be added to permit detection of incomplete application of the subsequent paint coat. 7. After erection bare spots shall be touched up with zinc chromate primer followed by one coat of aluminum paint as specified in H—5 and H—6. 8. The completed structure shall be given one field coat of aluminum paint as specified in section H-6, exeept ! that Prussian Blue shall be ommitted from the field coat. xxvli 1 II BIBLIOGRAPHY 1. Charles M. Parker, Steel in Action, 1943. 2. Alcoa, An outline of Aluminum, 1946. 3. Alcoa, Alcoa Aluminum and its Alloys, 1947. 4. The American Institute of Finins and Metallarsical Engineers, Seventy-five Years of Progress in the hineral Industry, 1947. E. Sutherland and Bowman, Structural Theory, Third Edition, 1949. 6. A.A.I.S.C., Steel Construction anual. 7. National Lumber Manufacturers Association, National Desisn Specifications for Stress Grade Lumber, 1944. 8. A.R.E.A., Specifications for Stress Grade Lumber, l944. 9. Sutherland and Bowman, Structural Design, 1938. 10. Glenn Murphy, Properties of Engineering Materials, 1949. ll. Urduhart and O'Rourke, Design of Steel Structures, 193p. 12. The James F. Lincoln Arc Welding Foundation, Desisn for Welding, 1948. 15. Johnson, Bryan and Turneaure, Modern Frame Structures, 1940. 14. L. J. Parkwardt, Wood as an Eneineerina Yaterial, 1943. r O ‘ ' . P . ‘ ' A ~ ‘ ‘ r ‘ 1 '\ ‘I . . _4 ' . . f , :1. . '1’ l . r ' ' ' . ./ n (‘I . I ‘ ,l ‘ \ . I ’ a . ‘ .\ , . ' I ' I ‘ . .. \ I \ r ' l ' C v . ‘l . . I I I ~ ‘ ROOM USE ONLY. WTV ‘ v v v . 1 I A . t I . 3 I I . z t; 4 . ' I x . V \\' . . .' . MICHIGAN STATE UNIVERSITY LIB I IIII IIII IIIIII IES RAR 3 1293 03071 0390