The Detroit times. [volume] (Detroit, Mich.) 1903-1920, 1910-10-05

cess>. 20 ~siiS sISrS' IA coi6mns
. epiItIngs ever shrse 80 csorts s.
Of the i've load Of All 'foors (ex-
cert the top or upper door and the
oo For wsrs6ouScs and factories.
sevsnty-nve t7s) per cent. OF the
For stores and buildings for
light notwithstanding purpoSss.
seventy t7o) per cent. OF the i've
FOR churches. school houses
and places OF public amusement.
seventy t7O per cent OF the hve
IT ONCE = buildings y, ID h nSssis.
Tenement houses. lodging houses
and stables. sixty t60) per cent
OF the live load
Variation from the above re-
quirements may be had only on
Sec. 3. LOADING OF FLOORS
AND BEAMS All wooden floor
ing between two CD toists or sup
ports. or any floor arch or prick;
or aimored concrete, or other NIL
ing between two CD supporting
joists, beams or girders. shall be
proportioned 10 carry not less
than ten (lo) per cent. more i've
load. than assumed Tor sueh ,o's's'
Ali beams. rafters. joists or
Orders, shall be proportional 10
carry all OF the dead load In add,
ton to the whole OF the imposed
uniformity distributed live LOAD
CARDS DISPLAYED. II shall be
the duty of every owner OF every
building OF class /. already con-
structed. or hereafter 10 be con-
structed, or OF his agent or OF the
vide. affix and display conspis9-
ously on each floor OF such build
ing, placard stating the load per
square foot OF floor space which
may with safety be applied TO that
p tssns,S o, ts Ser a,s asa part.
any hoor varies. then there shall
be such placards for each
varying part of such moor,
load any such floors or r.s any ~
extent than the load indicated up
on such placards. 1t shall be the
duty OF the occupants OF the
building TO maintain such pia
cards during their occupancy OF
the building or his agent shall
cause the same TO be properly
afiixed with each change of oc-
cupancy These piacards and com
putations shall be verified ana ap-
proved by the department atrxs o,
upon the respective floors OF the
different buildings
ARTICLE XII.
Iron and steel Construeticn-
Sec. 1. IRON AND STEEL
STANDARDS. See Article IN.
Sections 10. "a and Is.
Sec. 2. PHYSICAL AND CHEM
ICAL PROPERTIES. See Article
rs Sec see 3 FRAMING r., OF srRuc-
TUREs. See Article x. Section :,
Sec. 4. FACTOR OF SAFETY.
See Article X. Section 4.
Sec. s. UNIT STRESSES. In
all calculations for iron and steel.
the following maximum stresses
capacity:
Medium steel in tension 4oTo
OF It's yield point and never ex-
ceeding 1900 pounds per square
inch. net section.
pounds per square inch. net sec
Medium steel In compression:
The safe loads as computed by
column or strut formulea-as given
turers' Hand Book or In Text
Books on Standard Framed Struc-
Shop Rivets:
Shear. 10000 lbs. per square
inch; Bearing. 10000 lbs. per
square inch.
Field Rivets:
Shear. 1900 lbs. per square
inch; Bearing. 1900 lbs. per
square inch
Field Bolts:
,nes Shea s., sSeo lss per III. .ans ess
sQ1are inch
Y Wrought Iron:
Tension. $4,000 lbs. per square
and struts seventy i've t7sJ per
cent. OF amounts allowed for
medium steel
Cast Iron:
Tension. 5000 lbs. per square
inch; Shear. 5000 lbs. per square
compression.-The safe loads
as computed by column and strut
formulea as given In the standard
Steel Manufacturers Hand Book.
Sec. 8. DESIGN. All steel franz
ing shall be designed where prac-
coincide with the gravity line of
rolled and built up sections, avoid
ing eccentric loading.
Where eccentric or irregular
loading Is unavoidable. resulting
stresses must be carefully calcu-
lated and proper material provid-
ed TO care for such loading. using
any OF the applicable formulea
prepared for such cases. and as
set forth in Standard Text Books
on Steel Framed Structures.
All connections must be de-
signed to safely transmit the
superimposed loads.
Rivets should be used for all
shop work and for all field work
where practicable.
care must be taken to have all
bolts In a joint In bearing at the
same time. and the bearing Of the
> threaded portions OF bolt shall
not be taken into consideration In
caleulstins the strength OF the
Sec. Z. BEAMS AND ORDERS.
For beams and sbuilt-up girders
the maximum hbre stress shall not
exceed one-quarter (x) of the
breaking stress of the material
when computed according to the
following formuiea:
F.
3 Fs=fibre stress in pounds per
square inch. ae
M=bending moment in inch
pounds. u
- y==distance In inches from cen
ter OF gravity OF section to ex-
treme fibre.
I=noment Of inertia of the net
cross section OF section at the point
In consideration. In inchss-,
The compre ssion Aange of a
beam or girder shall be considered
: as acting as a column and shall
not be allowed to be unsupported
laterally for a distance excesdin Z
thirty t30) times In inches the
width OF the fiange In inches.
plafQ nfrdera shall ha nrnvfded