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Page 1: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 2: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 3: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 4: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 5: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

A COMPARISON OF THE EFFICIENCIESOF A TWO-HINGED AND A THREE-

HINGED STEEE ARCH

BY

ROBERT HERMAN RIESCHEi^RANK FAIKWELL BEEBV

THESIS

FOR TH K

DEGREE OP BACHELOR OF SCIENCE

IN

CIVIL ENGINEERING

IN THK

COLLEaE OF ENGINEERING

ITNITERSITY OF ILLINOIS

PRESENTED. JUNE. 1909

Page 6: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 7: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

UNIVERSITY OF ILLINOIS

June 1, i9o9

THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BY

ZRAM FAIRTOL BESBY and ROBERT HERlvIAN RIESCHE

ENTITLED A OQMPARISON OF THE EFFIOIENCIBS OF A TWO-HINGED AND A

THREE-HINGED STEEL ARCH

IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE

DEGREE OF^ - -BaclielDr jc^^^ Engineering

(2<i>o^ aX^^Instructor in Charge

APPROVED:

HEAD OF DEPARTMENT OF Clvil Engineering

145157

Page 8: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

UlUC

Page 9: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 10: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

Digitized by the Internet Archive

in 2013

http://archive.org/details/comparisonofeffiOOries

Page 11: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

_1-

The object of thia thesis ia to determine the relative

weights of the main .nembera of a steel roof-tru33 arch, firit

when acting as a three-hinged arch, and second when acting as a

two-hinged arch, the same loading being used in both cases.

The arch used i^ that of the Baltimore Armory (Eng.

Rec. Vol, 49 pp. 604), which was designed as a three-hinged arch.

This arch ha3 a span of 190 feet 3-3/4 inches, center to center

of hinges, and a rise of 86 feet 6 inches above the finished floor

line, the floor line being 1 foot 6 inches above the center of the

end pins. The tipper chord panel points are on the circumference

of a circle whose radius is IH feet 10 inches, the center being

17 feet 4 inches below the floor line. The lower chord panel pointa

are on the circumference of a circle whose radius is 91 feet 10

inchea, the center being 5 feet 4 inches below the floor line.

The arches are spaced 25 feet 10 inchea, center to center. The

upper chord is divided into nineteen equal panela, each panel being

12 feet 8-15/16 inches long. The roof is designed for a wind

load of 30 pounds per square foot of its vertical projection, and

for a snow load varying from 2 to 3n pounds per square foot of

horizontal projection of the upper six panels on each side of the

center. The specifications used in thi^ design were those given

by Ketchuni in his "Steel Mill Buildings", and are as follows:

Tensile 'tresses

Shapes, main niembera , net sections I6,ooo pounds

per square inch,

^^^^ 16,000 TDOunds per square inch.

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Page 13: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

-2-

Compre33ive Stre3ae3,

Shapes S = 16,000 - 70 l/r pounda per square inch.

Least allowable l/r = 125,

No metal leas than 1/4 inch thick shall be used.

All stresses in both the two and the three-hinged arch

are obtained graphically, and the stress and space diagrams <are

shown in Plate 1. Prom inspection, it was assured that a com-

bination of the dead and wind load stresses would give a maxim^jm

deflection at the free end when the two-hinged arch was designed

as a single truss. Therefore, the stresses resulting from this

combination were used in both designs.

The design of the three-hinged arch wa^ a simple theoret-

ical design. The air.i was to get the smallest section that would

carry the given loads, little attention being paid to the practical

considerations which might, in some cases, have required the use of

larger members. (See Tables 1 and 2).

The design of the truss, treated as a two-hinged arch,

was made according to the theory given by Ketchun in his "Steel

Mill Buildings." The stresses usei are given in Table 3. The

formulae used areA = PUL/e,^'= P'UL/e, and H =, where

^ is the horizontal deformation due to a horizontal thrust

H is the horizontal thrust required to keep the free end of

the arch, when designed as a simple truss, from moving;

H' is a horizontal thrust, arbitrarily chosen, (in this case

it is 20,000 pounds);

P is the unit stress in each member due to the loads;

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~3-

P* 1-3 the unit atreag in each member due to the horizontal

thruat H'

;

U ia the unit 3treaa in a inenber due to a unit horizontal

thruat applied at the free end of the aimple truaa;

L ia the length of the member in inches

;

E ia the modulus of elasticity of atructural ateel ('2BOOOOno),

The method of procedure in thia caae ia aa followa:-

The members were fir^t dealgned and the deflectiona

calculated (aee Table 4), aaauming the arch to act aa a aimple

truaa free to move at one end. Then, uaing the aectiona choaen in

Table 4, the deflectiona, cauaed by a horizontal thruat of 2n,000

pounda applied at the free end of the truaa, were calculated

(aee Table 5). From the formula H = it waa found that the

true horizontal thruat was 53,000 pounda, or 2,65 x 2n,noo pounda.

The atreaaea due to a horizontal thruat of 53,000 pounds were then

combined with those cauaed by the given loada. The members were

then redesigned u^ing thia combination of ^treaaea, and the defor-

mation computed. Prom the formula H = H'^ it waa aeen that these

muat be an additional horizontal thrust of 13,300 pounds, making

a total of 66,400 pounda or 3,315 x 20,000 pounds. In this manner,

after four trials, the true horizontal thruat of 66,600 pounds waa

determined and the final design made faee Table 7), The total

weight of the main members waa then determined (aee Table 8).

Conclua ion.

The weight of the main membera of this arch aa here

designed, treated both aa a two-hinged and a three-hinged arch, is

considerably below that of the arch as designed and erected at

Baltimore. It is alao lean than that found by Mr, E. B, Jordan

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-4-

in hi3 thesia of 1908 where he designed for a combination of dead

arid wind load 3 tresses.

When designed for dead and snow load stresses, the vveight

of the main nember of the truss, treated as a two hinged arch, is

27,200 poimda, and treated as a tliree-hinged arch, 25,400 pounds.

This gives an advantage of 1,800 pounds or, 7.1^, in favor of the

three-hinged arch.

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r

Page 19: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
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Page 21: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

rnDLEl THREE. hINQEO nRCH 5TPE35E3.

I\/IF' DeadLoad 3nowLoQd \NindLoad 01.-^3. L. D.L -^Wind MHX.5trc53 3trc5S 3tress

/7V -i-30/00 -1-3600 i-/63200 -h//a900 +163200/7V' /f If -^23800 -t/33900 '1

B-/ -hS7<000 -f- ^7O0 +233O0 -h 6/700 +82300 +6/700/' /f - 2300 II +32300

/-^ -65300 -28000 - 3000 -9/300 - 66300 - 9/300fi -/4200 II -773O0 ll

//-^ -hSSOCO -h38000 -h ^iOO H24/P00 -^-90400 +/24000n -h/9600 II +703600 /

1

2~d -i-3S/00 f34400 -7900^ •^69300 +76/00 +693002-J' ii -f22000 II +37/00 1

1

3-5 t/SMO -20000 -i-32/00 - 2000 +30/00 -20003-3' /I -/70W II + /000J-f -'/9300 -/sooo -f/0/00 '34S00 -9400 -34300

/< II - 9300 1

1

-E9300 1

1

H-^ -t7O000 -h/O3JO0 -9200 -h//3300 +60300 +/7330Of7^' -^36000 1

1

+/O6O00 $1

^'5 -^26200 -f20000 -7SOOO -h46200 + //200 +46200i'/3400 1

1

+39600 II

3-S - 8760 -3^000 h^2200 -42700 +33300 -427003'S // '26000 II '347O03-6 - 7200 - sooo -f- 69O0 -/2200 -300 ~722GO5-6' ll -37(^0 1

1

- /O900/7-€ -f9^6300 -i-79^00 -20200 -f/69900 +7O600 ^/69800/7-6' II -h-^6200 ll +/370006-7 -i- 8000 -h3300 - 7300 -h/3300 -t200 +/33006'-7' /I -h^/OO +/Z/00 1

1

3-7 -//600 -36200 i-46000 -47600 +34i-00 -47SOO3-7' // II -27300 II -39400 It

7-8 -h 300O -hS/OO 2300 -h70/00 + 7SOO +/0/007-8' /I ll II II II

/7-a 'h96000 -hSdOOO -26^00 t/790/?0 +7S600 +/79dOO/7-S' it II +743000 1

1

6'3 -+/8600 -29730 -hZ3/O0 ~2S200 +23/008-9' It /I -h/6300 ll +20800 ll

3-9 ~/6SOO -^3300 -h59^00 -60600 +42200 - 6O600

Page 22: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 23: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

TFiBLEl 1

IVIL lYl.

DeadLoad 5nowLdad WindLoad D.L ^d.L. D.L^W.L JVtf^X^

stress Stress Stress 5fr€5S D.L.-^5.L3-S' -76300 ~-f3aoo -34600 ~ eoeoo -3/4-30 -S06009-/€ -tSSOO - 3S00 -t/9000 -H 3OOO -i-27S30 + 3C009-/0' ii ~6/00 ii + 2400/7-/0 ^98000 -fS^OO -4-7000 +/92eoo +3/00O -h/92600/7-/0' It -^39730 1

1

+J37700 II

/O-// - Z300 H-//200 -230OO +-8700 '2S3'00 -+S730/O'-//' ti II -13500 1 • -76300 4 *

3~// -2Z000 ~3/000 -f74<^00 - 73OOO +-32300 -73OOOB-//' ii II -43200 II -63200 II

//-/a -i-/4-000 -i'3300 -t/0300 +/7SOO +24300 i-z/aoo//-/^' " If - 2000 II +/2000 II

^'/^ -^93000 -t/0/300 -63200 +-/96SOO +3/aoo +-/96300II -i-eaaoo +/63SOO •

«

B'/J -22000 -33O00 -i-s^aoo -7SOOO -^62800 -7310003-/3' It -30000 It -72030 „

/2-/3 -sooo i-3000 -/3700 -6OOO -24730 -6330If -h/3000 -f/OOO

/3-/4 -t/ZSOO -t/osoo -t2300 +20300 +20000 +20300/3-/r +2000 +/9300 II

-f-87200 -t/C27O0 -74300 +/S9900 +2900 +/S9900f 1 #

»

+7seoo II +/62800 ti

3-/3^ -/a/oo +90400 -e/zoo t7/730 -677003-/3' -34600 -73300 n

/f-/3- -/2eoo - 6000 - 78OO -/9SOO -20600 -/88004 * -f6200 1' - 6eoo 'I

/3--/e -^/9000 'i'/7000 -4730 +-36000 +/4300 +36300/3-/e' +380O +24800 if

/7ye -i-7(^soa ^97000 '80000 t/73800 - J200 +/73830F-/6' /< -f-79aoo It +/3e600 II

B-/7 -//ooo -37200 -1-89300 -^8200 +7SOOO -492303-/7' It -3'4800 ii -63900 II

/ev7 -/<3000 -/ZOdO -f2O0O '3JOOO '74^300 -33003/evz' 4* 1' +300 ft '73-SOO 4 1

/7VS -f/900O -i-2/300 '/0800 -h40300 +-S230 f-4O300It + 9330 II +2630O

Page 24: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 25: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

THBLE 1

\ AC h A DeadLoad 5nowLoad WindLoad D.L -^5.L /V13X.Ml M.

5tre55 Dtress 3trcs3 dtrc55 D.L^3L./7-/S i-62300 -^S2300 - 76^000 -f-/44SOO -h/3300 -+/44300

f

-f-Z9300 /I -+/420^00

B-/9 - 2200 -2070 -hSOSOO ~22900 -h73700 -229003-/9' -30S00 1

1

-32700 /f

/S-/9 -/7O00 -2^000 -h/0700 -4/000 -^6300 -^/OOO/6'/S' II -J6O0 /I -22600

-i/rooo i-23000 -/3700 -h40000 -+/300 -+>400OO

/9W It -t/3300 II -(-30300

-t4S300 -f-62O0O -easoo -I-//0300 -h20200 -h//0300

-h74300 II +/22600 .

3-2/ -i- 7000 -36CO -hSSSOO -f4000 -h73300 y-4^003-2/' -40SOO II -33JOO20-2/ -/6000 -26000 -t/SOOO -42^00 -^2000 -4^£^^020'2/' II -/2SOO 1

1

'23800 /f

2/-22 -h/4300 -t2/00O -/SOOO -+33300 ~3700 -+333002/'22' II +/eooo /I -^30300

/7'22 +34300 -+39600 -:32900 -+73900 -/S600 -h73900/7-22' -f-ejooo -h973003-2^ t/4300 'i-/O2O0 +^6800 -f24SOO -+6//00 i-24300B-23' // 1

1

-^^ooo /' ~9700 II

22-23 -/^2O0 -/9800 i~2SOOO -32000 -h/2300 -3200022''23' -2O300 1

'

-33OO0 II

23-24 -h/OOOO -*-/4-Soo -/azoo ^24600 - 8200 -+2460023-24' // -h/7SOO II +27600 II

fl^^4 -i-24000 -h22J00 -3/ZOO -+4^300 -7200 +4S300/7-24' '1 -^43000 -+2/000 //

3-2:3 -f-/S330 •f/SOOO -t2300O -+34300 -h4/300 -f-343003-23' /I /I - /J-^^ -t/ssoo It

24-15 -eroo -/OOOO -+23400 -/S700 -i-2/700 -767^024-23' -27SOO 1

1

-34200 //

23-2S -eooo - 2000 -/JO'OO - BOOO -/9SO0 - 300023-26' " -h 2600 1

1

-3400f/-26 -^2/200 -i-/7000 -eaoa +33200 +/4400 -t-36200/=/-26' f2S30a -h477003-26 -i-22000 -t33000 -f27SOO tS7000 -+^9300 -+37000

- -3500

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Page 27: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 28: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 29: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 30: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 31: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 33: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

riemberD.L.3 tress

S.L.S fre33

W.L.Stress

H.T3treSs5

DLs5.L.S tress

D.L. + W.L.

3 tress

27OOO ~ ^600 + J3 SOO ^ III SOO + 7^SOO+ 27 000 V/ 600 + 15 SOO 90/00

H-2 + 7/ Soo f 21 200 ' 7 SOO + // doo + 93 000 + G-^ 300+ 7/ 3oo + 21 20O +9 OOO + / / 800 + 30 3oo+ /5'OOO ^ /d doo -30 200 + 30&00 + 33 800 - 20 000+/^ ooo ^ I880O + 300O + 30 300 -^23 000+ // 50(? t /09OO -62300 +00 2oo + 2G ^00 - S 1 300

/ JOO + M0OO + 6 OOO +00 200 ^ /7S0O+ 6 SO o + /O OOO - 73 300 -I- -09 OOO + /6 SOO - 6G800+ 6 soo -t- /O OOO -h ^ OOO + 09 OOO + /o soo

/f-/o -J/ OOO - S OOQ - / /0OO - 70 OOO - >40 000 ' /03 000~3J OOO - 3 OOO - OOO + 70 OOO - 3S 000

/f-/2 -30 OOO -3j2>20o -132 700 ^93 ^oo - //6200 -232 7000-/2' ^QO OOO -3e2O0 - /S300 +g3 0oo -0)S 300

/I-M ^/390OO - 72000 -/&9 OOO +//S200 -2/1 SOO -323 soo//-/4' '/3950O ~ 72 OOO - 3 / SOO + f/3200 - /7/ 000

~2o8 OOO '//830O -220300 ^ /^^ 700 - 226> 300 -023OOO0-/6' -203 OOO -//d300 - SI SOO -* /00 700 -2J9'Soo

//-/8 -279JO

O

- /72 OOO -2^^ 2oo + /7/ OOO - 0S/ SOO -323 7000-/S' -270300 - /72 OOO - 76&00 1-/7/ OOO -33 3000-2O -355 SOO -23MOO -2S9 2oo ^/99 700 -636 900 -6/0 700

-355500 -23I0OO 70(^ /o o + /99 700 - -46 / SOO0-22 '^28 700 -268 SOO '2629oo +222 700 - 777200 - 69/ 6000-22' -023 700 -2Sd SOO - /3d 3od ^222 700 -36 7SOO0-2^ "^3506 -330 OOO -2J3 060 239 300 - 3 /SOOO - 70 000

0-2^' -•0dSooo -330 OOO -/ 7-0 OOO ^239300 -6S9 0000-26 -3/7300 -33S OOO -237OOO "^209 000 -372 dOO - 7S0OOO/5z/j + 30 SOO + 27 OOO + -^O OOO ~ /Ssoo + /// SOO ^ /20SOO^-/' 30 soo + 27 OOO 12 OOO - /S soo +9G SOO3-3 f 73 200 + 23 OOO + 6>f OOO - 0O 000 ^9>6 200 •^/302003-3' + 7320O •^23 OOO + /o soo - 30 00 -1-33 700

3-d ^ 76 soo + 27 20O + 82 soo - 0/300 /03 700 +/390003-3' + 76 SOO +27 200 + /2 30 -0/300 + 33 3003-7 + 7S60O -^2S9O0 ^33300 - 00900 ^ /03 SOO -^/670SO3-7' + 70 600 +29900 ->-J3 0OO '00900 t92 000

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Page 35: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

T/1BLE3

MemberD.L.

Stressd.J-.

3 tressW. L.

v5 tressH.T

•3 tr^55

D.L + S.L.

3 1 re 55

D.L + W.L.

5 tress

3-S ^ 3S OOO +^33000 + //J J'OO -J3 Joo + //s 300 + 27OS0OB-S' coo + ^3S0O + 200 -33 300 1 M eoo3-// + / 3 (h ooo + 673 OO^Si + /S/ 300 -79300 + 203 300 +237 3003-//' -1- /J&ooo t- 67S'0o ^29 Sao - 79 800 +/63 300

B'/3 + 13^ ooo /OO 000 + /83'6oo '77^3 Soo +234000 + 369 Goo

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Page 36: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 37: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 38: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 39: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 40: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 41: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 42: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 43: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 44: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 45: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 46: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 47: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 48: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 49: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 50: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 51: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 52: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 53: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 54: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 55: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 56: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 57: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 58: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 59: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 60: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 61: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

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Page 62: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 63: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

TABLE 3

Men?ber dectionLength

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Page 64: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

I

Page 65: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting

TABLE 8

Member Sect/ onLenafh

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FootWeight

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2 d.2o 7 3 /.3

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Page 66: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 67: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
Page 68: A comparison of the efficiencies of a two-hinged and a three-hinged ... · weightsofthemain.nemberaofasteelroof-tru33arch,firit whenacting as a three-hinged arch,and secondwhenacting
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