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


es and Church Houses:
With fixed seats, so pounds: with
movable seats. 100 pounds; floors Tor
dancing. l2b pounds; stairways. l2e
pounds: Hobbies and passageways,
100 pounds.
Schools:
Assembly halls. 100 pounds; class
rooms, 10 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 8, Theatres:
With fixed seats. 80 pounds; with
movable seats, 100 pounds STAIR
ways. 1875 pounds: Hobbies and pas
saceways. 100 pounds.
General:
Attlas when not used for hsblta-
ton, 20 pounds: roofs, 40 pounds:
sidewalks. ESQ pounds.
Sec. 2 REDUCTION OF LIVE
LOAD. In calculating the load on
footings, walls. piers. and columns
in buildings over three 20 s.o !,
OF the live load OF all noors eek
cept the top or upper hoor and tho
roof will be allowed.
For warehouses and factories.
seventy -nve ,15) per cent. or the
live load.
For stores and buildings for
light manufacturing purposes.
seventy t70D per cent. or the live
load.
For churches. school houses
seventy (7O per cent. or the i've
In Office buildings. hotels.
dwellings, apartment houses
Tenement houses. lodging houses
and stables. sixty COO per cent.
Variation from the above re-
quirements may be had only on
special and written permission
from the department OF buildings.
See. 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 nli-
ing between two Cd supporting
joists. beams or Orders. SHAH De
proportioned TO carry not less
than ten I0 per cent. more live
load. than assumed for such joists.
beams or girders.
All beams. rafters. 1oists or
girders. shall be proportioned TO
lion to the whole OF the imposed
uniformity distributed live load.
Sec. T. FLOOR LOAD PLA-
CARDS DISPLAYED. Ii shall DO
the duty OF every owner or every
building of class ]. already con-
structed. or hereafter to be con-
structed, or OF his agent or OF the
occupant OF the building. TO pro-
vide. affix and display conspicu-
ously on each floor OF such build
ing. placard stating the load per
square foot OF moor space which
may with safety be applied 20 that
particular floor. and II the
strength of the different parts Of
any floor varies. then there shall
be such placards for each
IL shall be unlawful to
part thereof. TO greater
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 or
the premises. and the owner OF
the building or his agent shall
cause the same 10 be properly
affixed with each change or oc-
cuparcy These placards and com
putations shall be verified and APP
buildings before, they are afixed
upon the respective floors OF the
different buildings
rWcturai Iron and steel Con"truction.
STANDARDS. See Article IN.
Sections ID. IA and 10.
Sec. 2. PHYSICAL AND CHEM
b ICAL PROPERTIES. See Article
Sec. 3. FRAMING OF STRUC-
rURES. See Article X, section 2.
Sec. 4. FACTOR OF SAFETY.
See Article y, Section 3.
Sec. g.. UNIT STRESSES. In
all calculations for iron and steel,
the following maximum stresses
will be allowed for safe carrying
capacity:
Medium steel In tension 45@e
of Its yield point and never ex-
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 as computed by
column or strut formulate as given
I'm the Standard steel Manufac-
turers Hand Book or in Text
Books on Standard Framed Struc-
lures
shop Rivets:
Shear, 10000 lbs. per square
inch: Bearing. 10000 lbs. per
square inch.
Field Rivets
Shear. $500 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-flve (75) 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
formulas as given In the standard
Sec. 8. DESIGN. All steel franz
ing shall be designed where prac-
tical 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 In unavoidable. resulting
stresses must be carefully calcu-
lated and proper material provid-
ed to care for such loading, using
any OF the applicable formulate
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
supsrimposed loads.
Rivets should be used for all
shop work and for all field work
where practicable
Where bolts are used In shear.
care must be taken TO have ali
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
calculating the strength OF the
Joint.
Sec. Z. BEAMS AND ORDERS
For beams and built-up Orders
the maximum fibre stress shall not
exceed one-quarter (h) OF the
breaking stress OF the material
when computed according TO the
following formulae:
Ny
F.
F=fbre stress I'm pounds per
square inch.
M=bendlng moment In inch