Excavated material shall be stored in neat piles,
so placed as to cause the least interference with the use of the roadway
or sidewalks. If so ordered by the Director, such excavated material
shall be promptly removed from the site of the work.
A.
Unless otherwise authorized by the Director as hereinafter
provided, and except where the excavation is in rock or comparably
stable soil, suitable open- or closed-type sheathing at least two
inches in thickness, securely fastened in place with whalers and braces
throughout the duration of the work, shall be placed in all trenches
having a depth in excess of three feet, shall be driven to the same
depth as the lowest part of the pipe, conduit or structure proposed
to be installed and shall be carried down in such a manner that the
bottom of the sheathing shall at no time be more than one foot above
the bottom of the excavation. Closed-type (tight) sheathing shall
be used where sand, subsurface water or similar conditions are encountered.
The Director may prescribe the type of sheathing for any project or
portion thereof. Whenever conditions make it necessary, the Director
may require that the sheathing be driven ahead of the excavation as
the latter proceeds.
B.
Unless otherwise authorized in writing by the Director,
sheathing and shoring shall be left in place with a cutoff line 18
inches below ground surface.
C.
The Director may, in his discretion, authorize that
the use of sheathing and shoring be omitted in whole or in part if
the horizontal distance from the edge of the proposed excavation to
the nearest edge of the pavement, water main or other surface or subsurface
structure is not less than the vertical depth of the proposed excavation
as measured from the highest point of such pavement, water main or
other subsurface structure.
B.
Any rock excavation within five feet of water or gas
main, pavement or other surface or subsurface pipe, conduit or structure
shall be done with very slight charges of explosives and the utmost
care shall be used to avoid disturbing or injuring said structure.
C.
The permittee shall use the utmost caution in properly
protecting all surface and subsurface structures from the effects
of blasting, and any damage done to such structures shall be promptly
repaired by the permittee or by such other parties as the Director
may direct, at said permittee's own expense.
D.
Sufficient warning shall be given to all persons in
the vicinity of the work before blasting. The site of the blast shall
be covered with heavy timbers, blasting mats or other devices to prevent
damages from flying rock fragments.
E.
The time of blasting and the manner and size of charges
must be satisfactory to the Director. The blasting shall be done only
by properly licensed individuals.
F.
The permittee shall give adequate notice to the City
and to the appropriate public service corporations before proceeding
with blasting in the vicinity of water mains, sanitary sewers, stormwater
drains and other drains or other public utility lines.
A.
Permittee may not backfill until the permitted work
is inspected and the Director approves the backfill process and material.
Where backfilling is completed without this inspection and approval,
the Director may require the permittee to uncover the work at its
own expense to allow proper inspection.
[Amended 1-28-1985; 4-28-1997]
B.
The material used to backfill the bottom of the trench
up to a level of two feet above the completed pipe or other structure
shall be clean earth, sand or rock dust and shall contain no broken
rock, stone or frozen earth.
C.
Above a level two feet higher than the top of the
completed pipe or other structure, the material used for backfill
shall be approved material containing no frozen earth and not more
than 1/3 broken rock, and no stone or piece thereof shall exceed 1/2
cubic foot in size.
D.
The space between the pipe or other structure and
the bottom and sides of the trench shall be packed full by hand and
thoroughly tamped as fast as placed and up to the level of the top
of the pipe or other structure, which shall then be covered by hand
to a level at least three feet higher than the top thereof, the backfill
material being carefully deposited and tamped in layers not more than
six inches thick.
E.
Tamping shall be done with a light tamper weighing
from six to eight pounds and shall be conducted in such a manner as
to secure compacted backfill without in any way injuring or disturbing
the completed pipe or structure. At least one man shall be provided
for tamping for each man engaged in backfilling.
F.
The use of power equipment or other mechanical means
for backfilling will not be allowed except with the prior written
authorization of the Director.
G.
Compacting the backfill by means of flooding or puddling
with water will not be allowed except with the prior written authorization
of the Director.
H.
When directed by the Director, concrete of 1,000 pounds
per square inch, commonly known as "K-crete," may be directed for
backfilling in lieu of earth fill.
[Added 1-28-1985]
A.
Tunneling under pavements or sidewalks will not be
allowed, but small pipes or conduits having a dimension of six inches
or less may be driven beneath pavements or sidewalks in such a manner
that the surface shall not be disturbed or injured, provided that:
(1)
The prior written approval of the Director is obtained.
(2)
No excavation in connection therewith shall be closer
than one foot to the edge of a sidewalk or 18 inches to the edge of
a pavement.
(3)
Such pipes or conduits shall be enclosed in sleeves
or larger pipes so that required replacements or repairs may be made
in the future without disturbance or injury to the pavement or sidewalk.
B.
In the event of damage to a pavement, sidewalk or
subsurface pipe or structure caused by driving such pipe or conduit,
the permittee shall repair and make good the damage at the permittee's
own expense.
