Albert Irvin Frye.

Civil engineers' pocket book; a reference-book for engineers, contractors, and students, containing rules, data, methods, formulas and tables online

. (page 72 of 182)
Online LibraryAlbert Irvin FryeCivil engineers' pocket book; a reference-book for engineers, contractors, and students, containing rules, data, methods, formulas and tables → online text (page 72 of 182)
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P ^7 (12)

na
^ which / is considered to be the working stress of the material, and f any
value between the working stress and the ultimate stress. It is to be noted
^ with / constant, the factor of safety increases as f^ increases, but not
proportionately. Strictly speaking, the formula applies only Vithin the
«la^ Hmit of the material, i. e., when f (and /) do not exceed fe. The
^'ahie of f should be above any possible value of /, and should always be
Plater than 2/ for maximum static loading, or its equivalent. Again, with
' ^/ the factor of safety is greater for long columns than for short.



500 dZ.—PROPERTIES AND TABLES OF COLUMNS.

P Pw
Author's Formula forColuinns. — From mechanics, f— /c +/*>=" T"*"/"



p(l+^) , whenco



'"^"Tfe "'

Again, the bending moment at center o£ column is

Af-Pto (14)

But according to Euler. P — — ^ — , whence (14) reduces to

M MP ,,_

'^-p-^T^TE/ (^«

Substituting this value of v in equation (13) we have

From the theory of flexure, we have,

M = j;fl,'^(f-h)-j{f-^)'j;U-P) (17)

Whence, by substitution, equation (16) reduces to

na \ naf na

So far, our reasoning: seems to be correct, but when we attempt to

solve equation (18) we nnd that p^j or na. Prom an examination of the

last form of equation (18) it will be seen that the first term p, equal to the

load per sq. in. on column, would be decreased by substituting unity for

the quantity ( 1 — — ) in the denominator, and hence would be on the side of

safety. Moreover, it would reduce to Fitter's formula (12), by making f—/;

thus, p — — —r" ' ^^* irom the above discussion, we are certain that, for any

na

column of given length I, p< na, and (l~-^) < unity. Assuming tents-

tively the value of Rittcr, p— j-, in order to arrive at an approximate

na



value of ( 1 — —\ in the second form of equation (18), we have p + — «/;

whence, by transpos
equation (18) gives



fPPP
whence, by transposition, p— / , or 1 ="t5 *^*^ ^^^ substituted in

na na j \

"-jfr <»»

/ na
This reduces still further to

p=-/ (sec 5-tan 6) (20)

the desired formula; in which tan <?•■ o — '

In using formula (20). find
Ist. The value of \/tan 6, from Table 1, on the following page,
2nd. The corresponding value of sec tf— tan 6, from Table 2.
3rd. Mviltiply this last value by / to obtain the allowable load pperaq. .

on column; / being the allowable working stress per 8q\iarein<

for a short column.

g^.^""8-;by the use of Tables 1 and 2, the value (sec. tf-tan B) in equati
u; call be transformed into a numerical quantity, orvdecimal factor. S
xamples. page «B. ^ ized byCoOglC



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592



Si.— PROPERTIES AND TABLES OF COLUMNS.



2. — Values op (Sec 5-tan 0) in Column Formula, Equation(20)
For Successivb Values op Vtan d. Table 1.
[Values of Vtan d may be derived from Table 1.]



>



0.50



1.000
.990
.961
.914
.853
.781



*c2



.010
.029
.047
.061
.072



0.50
0.60
0.70
0.80
0.90
1.00



.781
.703
.624
.547
.477
.414



1.00
1.10
1.20
1.30
1.40
1.50



f



.414
.360
.313
.274
.240
.212



^1



.054
.047
OSO
.034
.028



1.50
1.60
1.70
1.80
1.90
2.00






.212

.18^

.16

.1511

.130

.123



.024
.090
.017
.015
.013



Examples in the Use op Tables 1 and 2.
[From Column Ponnula, p=-f {sec d-tam 6), equation (20).]

Ex. 1. — Find the safe load, factor 4, of a medium-steel z-bar column
with fiat ends, whose length is 26 ft., sectional area 24.8 sq. ins., and radius
of gyration 2.6.

Solution.— From Table 1, Vtan ^-.058 — -.58; and from Table 2, the
, f

corresponding value of (sec 0— tan 9)«.72: hence the safe woridng load

f-.72x 15 000» 10.800 lbs. per sq. in., and the total safe load- 10 800 X
4.8-267 840 lbs.

Ex. 2. — Find the safe load, factor 5, of a vertical post of Douglas spruce
in a Pratt steel combination highway bridge, said post being 12 X 14 ins.,
28 ft. long, and with pin end bearings.

Solution. — ^The value of / for Douglas spruce (col. 4, Table 7, page 495)
is 1400. From Table 1. Vtan <?- A • f? =.933; and from Table 2. the cor-
resix>nding value of (sec <7— tan 0) is .456; hence total allowable load
P-.456X 1400X12X14- 107 251 lbs. (See also Table 3.)

Ex. 3. — What load would be carried by a column similar to that in
Ex. 2, but with flat ends?

Solution.— Table 1: t^ • If -.747; Table -2 equivalent -.588; hence
P-.588X 1400X 12X 14- 138 298 lbs.



Gordon's Formula for Columns. — Probably no other formula has been
so universallv accepted as that of Gordon — sometimes called Ranldne's
formula. Adopting the previous notation, it is deduced as follows: The
maximum outer fiber stress due to both compression and^nding is



whence



'-^^M^-^) ••••<"'



j'P-



1+



vy



(22)



Now the deflection v of the column is an unknown quantity, but Gordon

assumed it to be proportional to — , which assumption would be allowable

if the total fiber stress f were due to bending only. Substituting this iMt)por-
tional equiA^ent of i; in equation (21) and supplying the coefficient c whose
value IS to be determined by experiment, we have the general form:

p — ^- (»»






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CORDON'S FORMULA. STRAIGHT-UNE FORMULA. 603

For the working formula, the value aasigned to f is usually the ultimate
strength per sq. in. of a short column of the material, divided bv factor of
safet^r, as 4, 6, 6, etc. The coefficient c is an arbitrary constant determined
bv trials in fitting the curves of the formula to plattings from actual tests
of strengths of columns up to the points of failure, and making / ■■ ult.
strength -(-factor of safety. (See Sees- on Bridges and Buiidings tot special
application of Gordon's formula; also the tables following under this
•ection.)

C. Shaler Smith's Pormula for Wooden Columns. — This formula gives
values much too low for long colucms. It is reproduced here more for its
historical, than for iU actual working value. The formula is as foUows:



P"



f



i+.oo4^;



(24)



the ultimate strength of white pine being assumed at /,— 5000. The ends
of the column are to be fiat and firmly fixed; with concentric loading.

Straight-Line FormnUs. — Curved-line formulas, previously explained,
may be reduced to straight-line formulas by finding the equation of the
tangent to the ctu^e at the point of contra-flexure. Thus, in Pig. 5, page 589,
c is the point of contra-fiexure of the curve, and its tangent at that point cuts
the coordinate axes of the diagram at T and t; the resulting stiaight-line
formula for the elastic strength of the steel coltunn with pivot ends thus
reducing to



#'-85 400-169-^



(25)

in which 35 400-1.18 /e- 1.18X30 000; £ being assumed at 80 000 000 in
the present instance. If now this tangent is swimg slightly on the point c
so that the point T is lowered to 34 000. it will practically fit the curve for
a long distance, with the resulting equation



p- 34 000- 150-^



(26)



Straioht-Linb Formulas for Stbbl and Wrought Iron Ck>LUicNS.
(Reduced from data in Tables 1 and 2.)



Material.


Ulti.

mate

Stren'th


Elastic

Limit.

/e


Elastic Strength of Column.
Pounds per sq. in.


Pm Ends.


Pin & Flat.


Flat Ends.


Wrought iron —

Soft steel

Medium steel.. . .
Hard steel


AdOOO
50000
60000
70000


25000
30000
35000
40000


28500- 05y
35000-130-
41000-160^
46500- 185y


28500- 85-^
35000-115-^
41000-145^
46500-170^


28500- 75^
35000- 100^
41000-130^
46500-155-^



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d by Google



d by Google







22.— PROPERTIES AND TABLES OF COLUMNS.



Stcd Cdiioinfl. — Prom the pracediog discuMion of Column Pon
might readily conclude that, tor a column of given sectional are
length /, that column is the strongest which has the greatest r
fl[yration r. But this is not always true. To illustrate: On p
Fig. 20, we find the properties of the Hollow Circle, of outside dii

and inside diameter </», giving r ■• -g — ^ and A ■•0.7834 {jP'^dt

if we let A remain constant and gradually increase <^from sere
until it approach d, which must also gradually increase, out less ra
then r likewise increases in value from r —0.25 d (when the column i
circular cylinder) up to its maximum limit r»0.3535 d (when tlu
becomes a cylindrical shell whose thickness approaches zero),
quite apparent that before the maximum limit of r is reached, tt
column will fail through auxiliary OT stcondary stT€ss«St sitt up in
metal shell, causing it to buckle and collapse.

The Secondary Stresses, above described, may be provided ag
either (1) Making the metal thick enough, tnroughout, to withstai

(2) Providing longitudinal ribs, as in the case with the Phoenix col
Table 11. page 004) and other standard built-up columns, in

(3) Inserting (transverse) diaphrams at intervals along the colu
aone with very large sections.

Where Columns are Latticed, or where stay-plates are simply
independent (unsupported) portion should be calculated as a
column with its own radius of gyration.

Column Sections may be made up as follows: —
(A). — ^Two angles riveted back to back, forming a T-«ection,
(Aa). — Same as (A), but with round fillers or a plate riveted bet

angles, giving a greater radius of gyration.
(B). — Pour anKies and a web plate, forming an H-section, simil

rolled H -Column of Table 14. page 606. The distance bac

of angles should be in whole or half inches, and from

greater than width of web plate.
(Ba). — Same as (B). but with the addition of two channels rivet

backs of the angles, with flanges of channels projecting in
(Bb). — Same as (B). but with lattice bars instead of web plate.
(C). — ^Two channels and two plates, as per Fig. 6, below. See al

8. 9, and 10. pages 661, etc.
(Ca). — Same as (C). but with latticing instead of plates — one or bol
(Cb). — Same as (C). but with flanges of channels projecting in\i

latticing or stay plates instead of cover plates.
(D). — Same as (C). (Ca) and (Cb), but with plate and two azigl<

of channel.
(E). — Z-bar column. See Tables 6 and 7, pages 898. etc
Also other sections made up of a combination of these shapes.

To find the movement of inertia, /, and the radius of gyration,
column section, see Example, page 627, in connection with Tables 2
pages 639, etc.

The Channel Column, Pig. 6, is standard for all classes of con:
The following table gives the standard dimensions:

4. — Channel Columns — Standard Dimensions in Inchbj



Depth of


Width of












Channel
C


Plate
P


W


R


W-\-R


E


,ff*-r


15


18


5H


\H


7H


IH


•^


1


15


16


4>4


l?i


6>i


^H




1


12


16


6


IH


t^


^^




1


12


14


4


IH


IH




^


10


14


4Vi


\\i


5^


IvH




1


10


12
12
10






1^


M


i






i^......p.


8
8


^


2l^




1^


1^


Fig.



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STEEL Z-BAR COLUMNS.



699



— ^ToTAL Sapb Load in Thousand Pounds fob Z-Bar i^LUMNs
(Without Sidb Platbs.)
/» thickness of metal;
4 -area of cross-section of column;

v<- weight of column in lbs. per lin. ft., not including weight of rivets;
r- least radius of gyration.

Allowable stresses i
sq. in.: safety factor 4



on.

I p^ (- 12.000 lbs. for lengths of 90 radii or under:

or 4: 1 17.100- 67— for lengths over 90 radii.



(See opposite page for Dimennons.)



* A


fi;*


r


Length of Columns in Feet.


'^t.


Lbs.


rMin'.






12


14


18


22


26


30


34


38


42


46


50


K|9.31
A 11.7


81.7


1.86


111


111


98


84


70


67


6 -in. Col.
For columns
leas than 12
ft. long use

gven loads
rl2ft.


nal metal from
imns tends to In-
i of gyration of
ce the resulting
nal area by add-
etal will allow a
rease In the tab-
u But see next
with side plates.


99.^


1.90


141


141


125


103


91


74


H I3.e


40.2


1.88


168


163


143


124


104


84


A 16C


54. S


1.98


192


192


171


149


128


103


H n.t


50.t


1.90


211


211


187


162


136


111


A 20.0


67.9


1.95


240


240


216


188


160


132


H "3


38.2


2.47


i|fl


135


124


111


99


86


74


A 14.1


48.1


2.52


170


167


142


127


111


96


B.~Addltlo
%teB on ooli
the radlui
ctlon; hen
se In secUo
e-plate m
tlonatelnc
safe loadf
)r columns


H 17.1


58.0


2.67


205


192


174


165


137


119


A39.C


64.7


2.40


■^fc-l^


228


211


190


169


148


127


H 21 fl


74.4


2.55


262


245


221


198


174


151


S248


84.1


2.60


297


280


254


228


202


176


f5?«-3


89.2


2.62




315


292


264


235


207


179




III


H^O
H 31.9


98.fi


2.58


349


327


296


265


235


204


106.4


2.68


382


363


329


296


263


230


A 15 8

H$9.Q


63.7


3.06


«l !




189


179


165


151


137


123


108


94


^i


3.13




228


217


200


184


167


161


134


117


A 22 2


76.8


3.18


|8 '




268


267


237


218


199


180


161


141


H 24. £


83.S


3.10




294


278


257


236


214


192


170


149


A 27 1


94.2
105 2


3.16
8.21






832
871


317
357


293
881


269
805


246

278


221
262


197
225


173


H 39.S




199


H^.7


lll.C


3.13




392


373


344


316


287


269


230


202


121. «


3.18




430


412


382


a5i


320


289


258


228


132.6


3.25


^i la




468


453


420


388


365


322


289


266


nkj


72.7
85.2
97.8
106.2
118.6
130.9
137.8
149.9
162.1


3.67
3.72

r?s

3.75
3.73
3.68
3.66
3.64








257
301
345
375
418
462
486
529

m


246
290
335
360
405
447
466
506
646


230
272
314
337
380
418
436
473
610


214
263
294
314
354
390
406
440
476


198
236
273
291
829
362
376
407
489


182
217
252
268
303
334
346
374
403


166






198


{5 ^ Q






281


A m 2






?46


n ni'e






?78


U m'fi






806


n Fja e






816


ipi






841






867

















*Add weight of rivet heads.



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600



Si.—PROPERTIES AND TABLES OF COLUMNS.







Fig. 8.



7. — Carnboib 14-inch Z-Bar Columns.
With Side Platbs.
Note. — Diameter of Bolt in Rivet. K in.
For notation, A,w,r, safety factor, working formula,
etc., see top of page 1044.

For increase of safe load over tabulated values, the
area A may be increased proportionately by increasiiig
metal in side plates. ^



Dimensions and Properties


1


Safe Load in Thousand Pounds.




Two
Side
Pl'ts




Dim'n's A


w*


w3


Length of Column in Feet.


A


B Ins.


Lbs.


B


26t


28


80


34


88


42


46


60


14xH


.S.S


19A


6|i49.0


166.6


8.80


688


688


578


638


608


467


4JB


897


14x,V

14xH


19tt


6IS50.8
0|i52.6


172.6


3.81


609


609


604


568


621


486


449


412


??


19^


178.6


3.82


030


630


616


678


640


603


465


427


14xA


^.


{Kl


7^54.3


184.5


3.82


661


651


637


698


660


620


481


443


14xii


7A66.0


190.4


3.83


672


672


658


618


678


638


498


468


14xH


II


20tV

20H


7A57.8


196.4


3.84


608


603


679


638


607


666


614


473


14xfdL


7i^,l69.5


202.3


3.86


714


714


700


658


616


673


630


48S


14x4


^1


20^


7^*61.3


2X»A


3.85


735


735


721


677


634


600


647


603


14xJ^


•^r-4


7i|63.0


214.2


3.86


766


756


742


697


662


608


668


51S


14xH




i»A


65^*51 .0
6452.8

6kS4.5


173.4


3.76


612


612


603


1b6


619


482


446


W


u


.ss


19k


179.4


3.76


633


633


614


676


638


490


461


423






186.3


3.77


664


654


636


596


667


617


477


438


14xA


SJ


195i


o4


56.3


191.4


3.78


676


675


657


616


675


635


404


45S


14x&




194


7


68.0


197.2


3.79


696


606


678


686


604


552


610


466


14xH


19^


?)^.


59.8


203.2


3.80


717


717


699


656


613


670


627


4S4


14xC

14x4
14x^


20


61.5


209.1


3.80


738


738


720


676


681


687


643


499


^


7A


63.3


216.1


3.81


750


769


741


696


650


606


660


614


"••-H


7>4


65.0


221.0


3.82


780


780


762


716


609


622


576


629


14xH


.si

1!


\t^


6|i


54.6


185.6


3.78


656


653


633


503


658


618


473


li


14xi^


618


56.8


191.5


3.74


676


676


654


613


672


631


490


449


14xH


mi' m


58.1


197.5


3.76


697


697


675


633


601


649


606





14xA

14xH


19^ ni


59.8


203.4


3.76


718


718


697


653


610


666


623


479


19ll


7A


61.6


209.4


3.n


739


739


718


673


628


684


689


494


14x«
14xk
14x4

14x^«


II




7*4


63.3


215.3


3.78


760


760


789


603


647


601


665


510


20H




65.1


221.3


3.78


781


781


760


718


666


619


672


62S




20A


7_»


66.8


227.2


3.79


802


802


781


733


686


636


568


6iO


20M, 7ii


68.6


233.2


3.80


823


823


802


763


708


664


606


555


14x^g


.5.2


194


6H


58.2


197.8


3.71


698


696


673


681


688


646


602


460


u


7


59.9


203.8


3.72


719


717


694


650


606


662


618


474


T^


19>8


7A


61.7


209:7


3.73


740


738


716


670


626


680


636


490


u


^*


20


7K63.4


215.7


3.74


761


760


737


090


644


696


661


60S


1-a


^k


7iV^.2


221.6


3.75


782


782


758


710


663


615


668


520


14xH


II


7K66.9


227.6


3.76


808


803


779


730


682


638


684


53S


id


20H


7k 70.4


233.6


3.77


824


824


800


760


700


650


6or


561


t^^


20A


239.6


3.77


846


845


821


770


719


668


617


666


■*»H


7A72.2


246.4


3.78


866


866


842


790


788


686


688


5fil



* Add weight of rivet heads.



t 26 feet or less.



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Z-BAR COLUMNS. CHANNEL COLUMNS. Ml

LjB_ r^ 0* 8 — Carnboib Channel Columns — Flat Ends. 7*

J .Q. L Safe Loads* and Properties.

(Safe Loads are in Thotisand Pounds.)



Fig. 9.



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002 22.— PROPERTIES AND TABLES OF COLUMNS.



Pig. 9.



9. — Carnbgib Channbl Columns — ^Flat Ends.
Safe Loads and Properties.
^1 ^ ^^ (Safe Loads are in Thousand Pounds.)



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Ma



FIg.g.



CHANNEL COLUMNS. 603

10* 10. — Carnboib Channbl Columns — Flat Ends. 12*
Safe Loads and Properties.
(Safe Loads are in Thousand Pounds.)



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604



d^.—PROPERTIES AND TABLES OF COLUMNS,



11. — * Pr<bniz Stbbl Columns.
Dimensions, Properties and Loads.

'The dimensions given in the following table are subject to such slight
variations as are unavoidable in the manufacture of these shapes.

The weights given are those of the segments composing the columns,
and from 2 to 6 per cent must be added for weight of the rivet heads.

The safe loads specified are computed as being one-fourth of the tilti*
mate, or breaking loads, and as producing a strain, or pressure, in an axial
direction on square-end columns, of not more than 12,000 lbs. per square
inch for lengths of 90 radii and under.

The A, Bl, B2, and C columns have each 4 segments, the £ have 6.
and the G have 8 segments.

Any desired thickness between the minimum and mayimum can be
furnished.
Least Radius of Gyration ^ Dp X 0.8636.



One Segment.



Diameters, in Ins.



One Column.



Section.




D
Inside



Out-
side.



Over
Flan-
ges.



Area

of

Cross

Sec-

tion.

Sq.In.



Wt.

Frot

in

Lbs.



Least

Rad.

of

Gyra-
tion

in Ins



3di
1^^



A

m



4

4H

4M
4J«



3.8
4.8
6.8
6.8



12.9
16.3
19.7
23.1



1.45
1.60
1.55
1.59



10
47



Bl



h%

6

6>i



IS



6.4
7.8
9.2
10.6
12.0
13.4
14.8



21.8
26.5
81.3
86.0
40.8
45.6
50.3



1.95
2.00
2.04
2.09
2.13
2.18
2.23



74
90
106
126
144
161
178



B2
6A



9K
9H

9?i



7.4
9.0
10.6
12.2
13.8
15.4
17.0



25.2
30.6
36.0
41.5
46.9
52.4
57.8



2.39
2.43
2.48
2.52
2.57
2.61
2.66



80
106
127
146
166
185
204



C

7A



10.0
12.1
14.1
16.0
18.0
20.0
21.9
24.3
26.6
28.6
30.6
34.9
38.8
42.7



34.0
41.3
48.0
54.6
61.3
68.0
74.6
82.6
90.6
97.3
104.0
118.6
132.0
145.3



2.84
2.88
2.93
2.97
3.01
8.06
3.11
8.16
320
3.24
3.29
3.94
3.48
3.67



120
145
109

216
280
263
291
319
8U
167
418
466
£13



*By permission of Mr.D. W. Bowman. Chief Engineer Phoenix lionWoriks.



PHCENIX COLUMNS.
11. — Pb(xnix Stbbl Columns. — Concluded.



006



One Segment.


Diameters, in Ins.


One Column.




gs


Wt.




^0

Out-
side


Di


Area
of


Wt.


Least
Rad.


!§:§


Section.


§.s


in
Lbs.


D
Inside


Over
Flan-
ges.


Cross
Sec-
tion.
Sq.In.


pS)t

in

Lbs.


of
Gyra-
tion
in Ins.


1^5




^


9.3




"iV


\^i


16.5


560


4.20


196


/S>/


•£


10.8




11 1


19.1


65.0


4.25


229


Vs:^


M


12.3




111


15«^


21.7


74.0


4.29


260


ul ^


^


14.0




nil


15ii


24.7


84.0


4.34


296


16.7




12iV


27.6


940


4.38


331


St 1 u t;


■X


17.3




12tV


16,V


30.6


IM.O


4.43


367


^


10.0


E


12A
12^


16A


83.6


114.0


4.48


402


u


20.7


lliV


lOS


36.4


124.0


4.52


437


i


22.7




12A


16A


40.0


136.0


4.56


480


5 3a 1


24.3




12H


leS


43.0


146.0


4.61


516




20.0




12i{


16H


45.9


156.0


4.66


551


I


29.3




13tt


16H


51.7


176.0


4.73


020


Pig. 14.


IH


32.7




13A


17iV


67.6


196.0


4.84


691




IH


36.0




13A


17A


63.5


216.0


4.93


762




ti


"ToT




15^i


19H


24.3


82.6


5.54


290




12.0




16»^


19H


28.2


96.0


5.50


337


(^


tV


13.7




15^
155|


im


821


109.3


5.64


384


^^^^


^


15.3




19H

mi


36.0


122.6


5.68


432


5 / ;7


tV


17.0




Wi


40.0


136.0


5.73


479




^


18.7




15H


im


43.9


149.3


5.77


526


4^


20.3


G


16


20


47.8


162.6


5.82


572


8


22.0


14H


16^^


20H


51.7


176.0


5.88


620


23.7




iwl


20M


65.7


189.3


5.91


667


® J3\ »


25.3




2XA


50.6


202.6


5.95


715


r^::^


1


28.7




im


20?i


67.4


229.3


6.04


809


Ui?»




32.0




WA


20J8


75.3


256.0


6.13


904




1^


35.3




IIH


21


83.1


282.6


6.27


997


Pi«. 15.


38.7




i7H


21H


90.9


309.3


6.32


1091



d by Google



6(M



Zi.—PROPERTIES AND TABLES OF COLUMNS,



12. — Ultimate and Sapb Oi) Strbnoths op Hollow Round and
Hollow Rectangular Cast Iron Columns.
In the following formulas, C/ — 80 000 and 5- 10 000 lbs. per sq. in.:

Round Columns. Rbctangular Columns.
Square Square Pin Square Square Pin

Ends. & Pin. Ends. Ends. & Fin. Ends.

UorS _ UorS _ UorS _ UorS UorS U or S



(12L)« , ■ 8(12L)«
^'^'mcP "^ iaood»



i4.<i2L)i , .8(12L)_« , . 0(12L)« , .3(12L)«
*'^400d» aaOOii* "^ 6400d« "^ 160(W>



L— length of column in feet; d — (least) outside diameter in inches;
p— load in lbs. per sqtuuv inch on column to produce U or 5.







Round Columns.




1


Rectangular Columns.


L
d


Loads In 1000 lbs.


per square


Inch.


Loads In 1000 lbs. per square Indt


Square Ends


sq. and Pin


Pin Ends


Square Endslsq. and Pln| Pin Ends




TJlt.


Bate


TTlt.


Sate


Ult.


Sate


Ult.


Safe


Ult.


Safe


Ult.


Saff




Load.


Load.


Load.


Load.


Load.


Load.


Load.


Load.


Load.


Load.


Load.


Load.


1.0


67.80


8.47


62. .99


7.87


58.82


7.35


70.48




Online LibraryAlbert Irvin FryeCivil engineers' pocket book; a reference-book for engineers, contractors, and students, containing rules, data, methods, formulas and tables → online text (page 72 of 182)