WA9701-SP051104TRENCH SAFETY
SPECIFICATIONS
FOR THE
DENTON TAP ROAD 16 -INCH WATER LINE
CITY OF
COPPELL, TEXAS
Prepared for
JT DERSNER INC.
Project # 10190
TREN -TECH COMPANJR.
828 HOWELL DR �P�E O F T�'rgS t�l
COPPELL, TEXAS 7501 I
972-304-2171 ....................... ILLIAM P. PRICE
. �j1 : ... 22399
I have reviewed these Trench Safety Guidelines and and that the recommendati (t1`\ �
and procedures conform to OSHA guidelines and ons
herein ar TT7ERIEZD regulations. The calculations
with generally P engineering Practice.
II
RE IS ROFESSIO ENGINEER DATE
Entire contents copyright O by Tren -Tech Company. All rights reserved.
Reproduction in whole or in part without permission is prohibited.
1 ASSUMPTIONS
1.1 General. These specifications cover the basic requirements for shoring and/or sloping of
excavations for the installation of WATER LINES and SANITARY SEWER LINES for
the DENTON TAP ROAD 16 -INCH WATER LINE in the CITY of COPPELL, TEXAS.
1.2 This specification addresses the safety of workers in a trench excavation and does not, in
any way relieve the Contractor of his responsibility and liability to ensure the safety of the
project and workers.
1.3 It is not the intent of these specifications to specify every detail and procedure of the
trenching/shoring operations; nevertheless, they shall conform to the high standards of
engineering and of safe trench excavation.
1.4 The personnel protection systems shown in these specifications have been designed based
on information obtained from the project drawings and specifications.
1.5 In accordance with Revised OSHA (Appendix A to Subpart P effective March 2,1990),
the Contractor's "Competent Person" will conduct the required Soil Classification Tests.
If soils other than those previously identified are found, this specification will be revised.
During construction, the Contractor's "Competent Person" will monitor the soil
classification as required by OSHA 1926.
1.6 Contractor shall be responsible for selecting the appropriate safety system option shown
in these specifications, depending on trench depth and soil conditions.
1.7 The protection of existing structures and utilities which may be affected by these trench
excavations is beyond the scope of this report (See Sect.4.2)
1.8 The Contractor must identify a "Competent Person" in the Contractor's firm responsible
for performing inspections of the excavations to ensure that expected subsurface
conditions are present. NOTE -This person must be "Competent" as described in OSHA
1926.650(b).
1.9 It is the Contractor's responsibility to ensure that all excavation work and site conditions
are within the regulations as established by OSHA. Any property damage or bodily injury
(including death) arising from the use of these specifications, from the Contractor's
negligence in performance of contract work, or from Owner's failure to note exceptions to
these specifications shall remain the sole responsibility and liability of the contractor.
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Copyright 0 1993 by Tren -Tech Company
E DEFINITIONS
2.1 All definitions of section 1926.650 of Subpart P, Part 1926, of the Code of Federal
Regulations shall be by reference an integral part of this section.
2.2 "Sealing Engineer " - The engineer whose Texas seal is affixed to these specifications.
2.3 "The Contractor" -The contractor responsible to the owner for the excavation work
described herein.
2.4 "Competent" as described in OSHA 1926.650(b).
3.0 APPLICABLE -CO. AND STANbAIIDS
3.1 The Contractor shall perform all shoring work under this contract in accordance with all
applicable codes and standard safety requirements and regulations including:
3. 1.1 OSHA 2207, Construction Industry Standards (Part 1926,
Occupational Safety and Health Standards)
3.1.2 AISC Code of Standard Practice.
3.1.3 AISC Specifications of the design, fabrication, and erection of steel buildings
3.1.4 AITC Timber Construction Manual
3.1.5 AWS D1.1 Structural Welding Code
3.1.6 The Uniform Building Code
3.1.7 OSHA 2226
3.1 .8 U S Army Corps of Engineers EM 385 -1 -1
3.2 The latest edition (including supplements and revisions) of the above publications in
effect or promulgated at the time of the bid shall apply. Equipment fabricated to codes
and standards in effect at time of bid but later revised shall be acceptable provided such
revisions are not required by law.
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4.0 SHORING /SLOPING
4.1 Description.
This section covers the technical requirements of the trenching/shoring work.
4.2 Existing Structures.
Where existing buildings, other utilities, streets, highways, or other structures are in close
proximity: to the trench, or may otherwise be affected by the proposed trenching
operation, the Contractor shall provide adequate protection by the use of sheeting and
shoring to protect the structure, street, or highway from possible damage. In the case of
utilities, the Contractor may elect to remove the utility, provided that the removal and
subsequent replacement meet with the approval of the engineer, the utility owner, or
whoever has jurisdiction of the structure. In all cases, it shall be the responsibility of the
Contractor to protect public and private property and any person or persons who might, as
a result of the Contractor's work, be injured.
4.3 General Trenching and Shoring Requirements.
The Contractor shall be solely responsible for trench safety provisions meeting the
applicable requirements of the United States Department of Labor - Occupational Safety
and Health Administration, including subpart P, Part 1926, of the Code of Federal
Regulations. All trenching operations and procedure shall also conform to the
requirements listed in this specification.
4.1.1 The requirements of sections 1926.650 and 1926.651 of Subpart P, Part
1926, of the Code of Federal Regulations shall be by reference an integral
part of this section.
4.4 REQUIREMENTS PRIOR TO EXCAVATION
4.4.1 Known underground installations are shown on the site plans. It is the Contractor's
responsibility to verify exact locations in the field.
4.4.2 Before any individual enters an excavation, the excavation will be inspected by a
"Competent Person" to ensure that trench excavation has been performed according to
this specification and OSHA requirements and to ensure that no anomalies are observed
which may effect the safety of the trench project. Note -This person must be "Competent"
as described in OSHA 1926.650(b).
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F 4.5 REQUIREMENTS DURING EXCAVATION
4.5.1 During excavation, the exact location of existing underground installations shall be
determined by the Contractor, and when uncovered, proper precautions and supports shall
be provided so as not to cause a hazard to the workmen or the project.
4.5.2 Daily inspections of the excavations shall be made by the Competent Person ". If there is
evidence of possible cave -ins or slides, all work in the excavation shall cease until the
necessary precautions have been taken to ensure the safety of the workmen and the
trench. Note -This person must be "Competent" as described in OSHA 1926.650.
Excavations shall be inspected after every rainstorm or other hazard- increasing
occurrence to ensure safety of the workmen and the trench..
4.5.3 Excavated material shall be stockpiled a distance away from the trench, so as not to affect
the trench stability. The Contractor's means and methods will determine the distance. As
a minimum to protect the workmen from falling debris, the toe of the stockpiled soil shall
be no closer than two(2) feet from the edge of the excavation.
4.5.4 All precautions must be made to prevent surface water from entering the trench
excavation. Adequate drainage must be provided in the area adjacent to the excavation.
4.5.5 Operation of heavy equipment adjacent to the edge of the trench may cause instability.
The Contractor is responsible for the means and methods of excavation, and therefore, for
loads imposed on the trench excavation and shoring design.
4.5.6 The Contractor must take precautions to protect the face of the excavation from exposure
to excessive drying, water, or freezing.
4.5.7 Water shall not be permitted to stand in the bottom of the trench and suction pumps of
adequate capacity shall be installed to ensure that such standing water is removed.
4.5.8 The Contractor shall provide a positive means of ensuring that hydrostatic pressure does
not build up behind the shoring or shields.
4.5.9 If a condition requiring the use of a different method of shoring is encountered, this
specification will be revised.
4.5.10 Remove shoring units from bottom to top as backfilling proceeds.
4.5.11 When backfill is within five(5) feet of the top of the trench, all shoring may be removed,
unless the trench conditions indicate a hazard.
4.5.12 No person shall be exposed to the lower portion of the trench after shoring has been
removed.
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Copyright 0 1993 by Tren -Tech Company
4.5.13 Additional shoring of larger sizes may be installed.
4.5.14 Ladders or other adequate means of exit must be provided and located so as to require no
more than twenty- five(25) feet of lateral travel.
4.5.15 When two(2) trenches intersect, both trenches must be protected to a distance of not less
that the depth of the deepest trench.
4.6 REQUIREMENTS FOR CONMED SPACE
4.6.1 Prior to construction the contractor shall identify any areas near the proposed excavations
that could expose workmen to harmful levels of atmospheric contaminants (i.e. landfills,
manholes or materials storage).
4.6.2 During construction, before workmen are allowed in an excavation or existing structure,
the contractor shall test the air quality at these previously identified areas for hazardous
atmospheres in all excavations greater than four (4) feet in depth. Atmospheres containing
less than 19.5 percent oxygen or more than 20 percent concentration of flammable gas
shall be deemed "hazardous" adequate precautions shall betaken.
4.6.3 Retesting of work areas shall be conducted as often as necessary to ensure that the
atmosphere remains safe for workmen.
4.6.4 During construction, emergency rescue equipment shall be readily available where
potentially hazardous conditions are expected to develop.
4.6.5 As a minimum, the contractor shall have on site the following emergency equipment.
Breathing apparatus, a safety harness and line, or a basket stretcher. During construction
in potentially hazardous areas, the required equipment shall be attended.
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Copyright 0 1993 by Tren -Tech Company
Copyright 0 1993 by Tren -Tech Company
SECTION 5.0
SITE SPECIFIC EXCAVATIONS
AND
SHORING SPECIFICATIONS
FOR
WATER LINES
AND
SANITARY SEWER LINES
Copyright 0 1993 by Tren -Tech Company
5.1 EXCAVATIONS SPECIFIC TO THIS PROJECT
16" WATER LINE
LOCATION
MAX.DEPTH
OPTION
NOTES
0 +00 TO 0 +11.00
15.5
1,111
INSTALL 16" W.L.
0 +11.00 TO 0 +84.00
INSTALL BY BORE
0 +84.00 TO 13 +47
15.5
1,11
INSTALL 16" W.L.
13 +47 TO 13 +77
INSTALL BY BORE
13 +77 TO 14 +87.00
16.5
1,111
INSTALL 16" W.L.
14 +87.00 TO 15 +79.00
INSTALL BY BORE
15 +79.00 TO 16 +69.00
17.0
1,111
INSTALL 16" W.L.
16 +69.00 TO 17 +30.00
INSTALL BY BORE
17 +30.00 TO 22 +75
8.5
I, II, III
INSTALL 16" W.L.
22 +75 TO 23 +05
INSTALL BY BORE
23 +05 TO 25 +47
8.5
I, II, III
INSTALL 16" W.L.
25 +47 TO 26 +00
INSTALL BY BORE
26 +00 TO 26 +30.
11.0
I, II, III
INSTALL 16" W.L.
26 +30 TO 26+60
INSTALL BY BORE
26 +60 TO 27 +06.0
26.0
I, II
INSTALL 16" W.L.
27 +06.0 TO 28 +19.0
INSTALL BY BORE
28 +19.0 TO 31 +86
27.0
I, II
INSTALL 16" W.L.
31 +86 TO 32 +16'
INSTALL BY BORE
32 +16 TO 36 +26
9.5
I, II, III
INSTALL 16" W.L.
36 +26 TO 36 +56
INSTALL BY BORE
36 +56 TO 40 +10.29
10.5
I, II, III
INSTALL 16" W.L.
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Copyright 0 1993 by Tren -Tech Company
8" SANITARY SEWER LINE
LOCATION MAX.DEPTH OPTION NOTES
0+00 TO 1 +17.38
INSTALL BY BORE
NOTE: Trench shield(s) and/or slope (Option I or II) shall be used for personnel protection at the
location of the bore pits. If trench shields are employed, end protection shall be accomplished
with appropriately rated trench shields or interlocking sheet pile (PZ -27 or equal installed
horizontally). These members shall be installed so as to rest on the ends of the main trench
shields.
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Copyright C 1993 by Tren -Tech Company
5.2 SHORING CONSIDERATIONS FOR THIS WORK
5.2.1 Trenches more than five(5) deep shall be shored, laid back to a stable slope, or some
other equivalent means of protection shall be provided where employees may be exposed
to moving ground or cave -ins. Trenches less than five(S) feet in depth shall also be
effectively protected when examination of ground indicates hazardous ground movement
may be expected.
The Contractor will have Options I, II or III for providing such protection.
5.2.2 Lateral Earth Pressure: P = We(H +Hq)
Assumed Soil: Clay H q
P= a uniformly distributed lateral soil pressure, in lbs. /ft
We= Effective Soil Weight, pcf(Use 45 psf Type "B" Soil)
H= Depth of excavation from top of supported bank to WE 45
bottom of excavation in feet. H
Hq= Equivalent Height of Surcharge, in feet.
Reference OSHA Rules and Regulations -Part 1926 of 29 CFR Ali
as amended by the Federal Register Volume 54, Number 209,
October 31, .1989
Maximum anticipated lateral earth pressure for this project is 1305 "PSF"
5.2.3 Option I The Contractor can use Slope as shown in the Option I section of the
specification. Applicable slopes may be obtained by either straight cut or benched
method. Vertical cuts for the benched method shall not exceed four(4) feet. Easement
restrictions may limit the use of this option. See Drawing Option I.
5.2.4 Option II , The Contractor may use a Trench Shield as shown in the Option II section of
this specification. Requirements set forth in this Option shall include curricular trench
shield(s) and or manhole boxes. All slopes above trench shield(s) shall conform to
guidelines set forth in Option I. Trench shield(s) used on this project will be required to
carry a minimum "PSF" as specified. Certification of trench shield(s) or manufacture's
"tabulated data" shall be available for verification during construction. See Drawing
Option II.
5.2.5 Option III' The Contractor can use Trench Shores as shown in the Option III Section of
this specification. Shores are to be installed as shown with horizontal spacing
determined by the depth of cut and soil type but shall not exceed 6 feet. See Drawing
Option III. If there is raveling of the trench wall, the contractor shall install plywood
behind the shores as shown on the Option III drawing.
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Copyright 0 1993 by Tren -Tech Company
TRENCH SAFETY SPECIFICA TIONS
Spoil Material
: 1 11�
V
H
3'6" Single Bench is
allowed in stiff clay —
SLOPE
The contractor may use the
benched method of "slope ".
HN - REQUIRED SLOPE PER SOIL TYPE
H/V = 3 /4 to 1 Stiff clay less than 12 feet in depth (Type "A ")
H/V =1 to 1 Stiff clay or weathered limestone (Type " A " or "B ")
H/V = 1 %2 to l Silty clays or saturated material (Type IV")
H/V = 2 to 1 Fill material or loose soil.
NOTES
1. All trenches shall be dewatered as specified in 4.5.7
2. All slopes assume sufficient right -of -way exists.
3. All slopes shall be flattened an additional %2 foot if an existing parallel utility line is
located within the horizontal distance equal to the depth of the new utility excavation.
4. No spoil or equipment shall be permitted nearer than 2 feet from the edge of the excavation.
5. A single 3' 6" vertical bench maybe used in "stiff clay" only.
6. Exposed existing utility lines are to be supported.
OPTION I
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TRENCH SAFETY SPECIFICATIONS
OPTION H
TRENCH SHIELD
Spoil Material
;.
1' Bench is recommended
V; \
H
Sloped portions of the excavation shall
begin 18" below the top of the trench
shield(s) and conform to guidelines
set forth in Option I.
Trench shield(s) may be benched 2 feet
in "stiff clay ".
Requirements and methods stipulated
herein will apply to "manhole boxes"
and/or "circular shields" that have been
manufactured for personnel protection.
NOTES
1. Trench shields shall be inspected and be free of structural defects that may impair their proper function.
2. Trench shields shall be used in accordance with the manufacturer's guidelines and recommendations.
3. Trench shields shall be installed so as to prevent any lateral or other hazardous movement.
4. Personnel shall not be allowed in the trench shield during its installation or removal from the excavation.
5. When shield(s) are stacked, the upper shield shall be rated for its physical depth in the trench.
6. Trench shield(s) used on this project shall be rated to withstand anticipated "PSF" (left side of graph) for depth
of cut indicated below. Manufacture's tabulated data or certification shall be maintained on site.
1400 1
----------------
1200
1000
800
600
400
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ------------------------------------------
200 '
5 Feet 10 Feet 15 Feet 20 Feet 25 Feet 27 Feet
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Copyright (D 1993 by Tren -Tech Company
TRENCH SAFETY SPECIFICA TIONS
OPTION III
SHORING
Plywood installed behind
shores to prevent raveling.
NOTES
1. Shores shall be double stacked when trench depths exceed nine (9) feet.
2. Maximum horizontal spacing for double stacked shores shall be five (5) feet.
3. Maximum allowable depth of cut for this Option shall be fourteen (14) feet.
4. Aluminum hydraulic shoring may be used in Type "A" or "B" soils only.
5. Maximum horizontal spacing of shores in Type "A" soil shall be 6 feet.
6. Maximum horizontal spacing of shores in Type "B" soil shall be 5 feet.
7. The contractor's competent person shall inspect shores and verify that they are in good working order.
8. The hydraulic shores shall have a minimum working pressure of 750 psi.
9. The contractor shall adhere to the shoring manufacturer's guidelines for use in trench excavations.
10. If there is evidence of raveling or caving the contractor is required to install 1'/ thick plywood or 1 /4" thick
14 ply arctic white birch (Finnland form).
11. Spoil material will not be allowed nearer than 2' from the edge of the excavation.
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Copyright 0 1993 by Tren -Tech Company