The Detroit times. [volume] (Detroit, Mich.) 1903-1920, 1910-12-07
COMMON COUNCIL



pounds Hobbies and passageways.
100 pounds.
schools.
~ Assembly halls. 100 pounds; class
rooms. 80 pounds: halls and corri--
doris. 80 pounds: stairways. 100
pounds.
All other buildings in this class,
First floor. 100 pounds: all other
floors. so pounds.
Class g. THEATRES
With fixed seats. so pounds; with
movable seats. 100 pounds; stair
ways. i25 pounds: Hobbies ana pas
sageways. 100 pounds
Attlcs when not used for habita-
ilou. 20 pounds; roofs. 40 pounds.
sidewalks. 25O pounds.
Sec q REDUCTION or LIVE
LOAD. In calculating the load on
footings, walls. piers. and columns
in buildings over three t3 stories
In height. the following reduction
OF the live load OF all noors teA-
cept the top or upper moor ana the
roof will be allowed.
For warehouses and factories,
seventy-five ts5) per cent. OF the
live load.
For stores and buildings for
light manufacturing purposes
seventy 0o) per cent or the I'VE
For churches. school houses
and places OF public amusement.
seventy 600 per cent OF the live
load.
In office buildings. hotels.
Tenement houses. lodging houses
and stables. sixty t6o) per cent
Of the live load.
Variation from the above re-
quirements may be had only on
special and written permission
Aan ft,na nf
Sec. 3. LOADING OF FLOORS
AND BEAMS. All wooden floor
Ing between two CD Joists or sup
ports or any floor arch OF brick,
tile or concrete, or any reinforced
or aImored concrete. or other NIL
Ing between two 90 supporting
joists, beams or girders. shall he
proportioned Ia carry not less
than ten b0) per cent. more i've
load. than assumed for such 1olsts.
beams or girders.
All beams. rafters. Joists or
Orders, shall he proporttoned TO
carry all OF the dead load In add
ton to the whole OF the Imposed
uniformly distributed live load.
Sec 4 FLOOR LOAD pLA-
CARDS DISPLAYED. IL shall DO
the duty OF every owner or every
building OF class l. already CON
structed. or hereafter To be con
structed. or OF his agent or OF the
vide. atiix and display .ronspicu-
ously on each floor OF such build
ing, IA plaCard stating the loGd per
square foot OF floor space which
may with safety be applied TO that
particular moor and if the
strength OF the different parts OF
any floor varies. then there shall
be such plaCards Tor each
varying part OF such hoor.
IL shall be unlawful TO
Ylu
part thereof TO greater
extent than the load indicated up
on such placards II shall lie the
duty OF the occupants or the
building to maintain such pla-
cards during their occupancy OF
the premises. and the owner OF
the building or his agent shall
cause the same To be properly
affixed with each change or oc-
cuparcy. These placards and com
putations shall be verified and ap.
buildings before they are affixed
upon the respective floors or the
different buildings.
ARTICLE MI.
neutral Iron And stre, S%".', s.c s.;.1
STANDARDS. See Article TX.
Sections 10. IA and Is
Sec. z. PHYSICAL AND CHEM
!CAL PROPERTIES. See Article
Sec. 3. FRAMING OF sTRUC-
TIRES See Article X, section 2
See. 4 FACTOR OF SAFETY.
See Article y. Section g.
See s. UNIT STRESSES. In
all calculations for iron and steel
viii he allowed for safe carrying
capacity.
Medium steel In tension +5E
OF it, yield point and never eN-
ceeding 1900 pounds per square
inch, net section.
Medium steel in shear 10000
pounds per square inch. net sec
ton
Medium steel in compression:
Tho safe loads az computed by
column or strut formulate as given
In the standard Steel Manufac-
turers' Hand Book or In Text
Books on Standard Framed Struc-
lures.
shop Rivets:
Shear. 10000 lbs. per square
square inch.
Field Rivets:
Shear. 800 lbs. per square
inch Bearing. $1,000 lbs per
square inch.
Field Bolts
Shear. 5000 lbs per square
inch Bearing. 1900 lbs per
square inch.
Wrought Iron.
Tension. $4,000 lbs. per square
Compression. - For columns
and struts seventy five C75) por
cent: of amounts allowed for
medium steel
Cast Iron:
Tension, 5000 lbs. per square
inch; Shear 5000 lbs. per square
inch.
Compression The safe loads
as computed by column and strut
formulas as given In the standard
Steel Manufacturers Hand Book
Sec. q. DESIGN All steel franz
ing shall be designed where prac-
teal TO have the line OF stresses
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 or the applicable formulate
prepared for such cases, and az
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 held work
where practicable
Where bolts are used In shear,
care must be taken TO have all
bolts In Joint In bearing at the
same time. and the bearing OF the
threaded portions or bolt shall
not be taken into consideration in
calculating the strength OF the
Joint
Sec. Z. BEAMS AND ORDERS
For beams and built-up girders
the maximum fibre stress shall not
exceed one-quarter N OF the
breaking stress OF the material
when computed according To the
following formulate:
NV
F.
-t=hbre stress In pounds per
square inch
M=bendins moment in inch
pounds
y--dlstance ~ inches from ecu
ter OF gravity OF section 10 cx d!