SS0201-SP040601 TRENCH SAFETY
SPECIFICATIONS
FOR THE
COPPELL ROAD/SERVICE CENTER SEWER
COPPELL ROAD TO GRAPEVINE CREEK
CITY OF
COPPELL, TEXAS
i[
Prepared for
FOX CONTRACTORS
Project # 8841
TREN- TECH COMPANY
828 HOH."ELL DR.
COPPELL, TEXAS 75019
972-304-2171
I have reviewed these Trench Safety Guidelines and find that the recommendations
DATE
EnOre contents copyright 0 by Tren-Tech Company. All rights reserved.
Reproduction in whole or tn part without permi*sion i* prohibited.
1.0 DESIGN ASSUMPTIONS
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
General. These specifications cover the basic requirements for shoring and/or sloping of
cxcavations for the installation of SAN1TARY SEWER LINES for the COPPELL
ROAD/SERVICE CENTER SEWER COPPELL ROAD TO GRAPEVINE CREEK in
thc CITY of COPPELL, TEXAS.
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.
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 sale trench excavation.
The personnel protection systems shown in these specifications have been designed based
on information obtained from the project drawings and specifications.
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.
Il'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.
Contractor shall be responsible for selecting the appropriate safety system option shown
in thesc specifications, depending on trench depth and soil conditions.
The protection of existing structures and utilities which may be affected by these trench
excavations is beyond the scope of this rcport (Sec Sect.4.2)
The Contractor must identify a "Competent Person" in the Contractor's firm responsible
Ibr performing inspections of the excavations to ensure that expected subsurface
conditions are present. NOTE-This person nmst be "Competent" as described in OSHA
1926.650(b).
It is the Contractor's responsibility to ensure that all excavation work and site conditions
arc within the rcgulations 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.
1
2.0 DEFINITIONS
2.1
2.2
2.3
2.4
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.
"Sealing Engineer"- The engineer whose Texas seal is affixed to these specifications.
"The Contractor"-The contractor responsible to the owner for the excavation work
described herein.
"Competent" as described in OSHA 1926.650(b).
3.0 APPLICABLE CODE AND STANDARDS ~
3. I The Contractor shall perfom~ 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, f~abrication, and erection of steel buildings
3.1.4 AITC Timber Construction Manual
3.1.5 AWS DI.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.
2
Copyright ((7 1993 by Trcn-Tech ('ompany
4.0 SHORING/SLOPING
4.1
4.2
4.3
Description.
This section covers thc technical requirements of the trenching/shoring work.
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.
General Trenching and Shoring Requirements.
Thc Contractor shall be solely responsible for trench safety provisions meeting the
applicable requirements of the United States Department of Labor-Occupational Safety
and Health Adlninistration, 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.
4.3. l
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
4.4.1
4.4.2
REQUIREMENTS PRIOR TO EXCAVATION
Known underground installations are shown on the site plans. It is the Contractor's
responsibility to verify exact locations in the field.
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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4.5 REQUIREMENTS DURING EXCAVATION
4.5.1
Duriug excavation, the exact location of existing underground installations shall be
determined by the Contractor, and when uncovered, proper precautions and supports shall
bc provided so as not to cause a hazard to the workmen or the project.
4.52
Daily inspections of the excavations shall be made by the Competent Person". If there is
cvidence et' possible cave-ins or slides, all work iu the excavation shall cease until the
necessary precaufions have been takeu to ensure the safety of the workmen and the
trench. Note-This person must be "Competent" as described in OSHA 1926.650.
Excavations shall bc inspected after every rainstorm or other hazard-increasing
occurrence to eusurc 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 thc 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 responsiblc for the means and methods of excavation, and therefore, lbr
loads imposed on the trench cxcavation 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 docs
not build up behind the shoring or shields.
4.5.9 If a condition requiring the use of a difl'ercnt method of shoring is encountered, this
specification will be revised.
4.5. l 0 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.
4
('opyrigh~((' 1993 by hen rcch ('ompany
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 CONFINED SPACE
4.6.1
4.6.2
4.6.3
4.6.4
4.6.5
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).
During construction, before workmen are allowed in an excavation or existing structure,
thc contractor shall test thc 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 "bazardous" adequate precautions shall be taken.
Retesting of work areas shall be conducted as often as necessary to ensure that the
atmosphere remains sale for workmen.
During construction, emergency rescue equipment shall be readily available where
potentially hazardous conditions are expected to develop.
As a minimum, the contractor shall have on site the following emergency equipment.
Brcathing apparatus, a safety harness and line, or a basket stretcher. During construction
in potentially hazardous areas, thc required equipment shall be attended.
5
SECTION 5.0
SITE SPECIFIC EXCAVATIONS
AND
SHORING SPECIFICATIONS
FOR
SANITARY SEWER LINES
6
Copyright fo; 1093 by [rcn-'lech Company
5.1 EXCAVATIONS SPECIFIC TO THIS PROJECT
SANITARY SEWER LINE "A"
LOCATION MAX. DEPTH OPTION
1+00 TO 6+05 17.5 1, li
6+05 19.5 1, 11
6+05 TO 11+66 18.5 1, 11
11 +66 19.5 1, 11
11+66 TO 15+85 18.0 1, II
15785 19.0 i, I1
15+85 TO 18+78 21.0 i, I1
18+78 TO 19+38
19+38 TO 19+48 18.0 I, I1
19+48 20.0 I, 11
19+48 TO 19+55 18.0 1, I1
19+55 20.0 1, 1I
NOTES
INSTALL 18" S.S.
CONST. MANHOLE
INSTALL 18" S.S.
CONST. MANHOLE
INSTALL 18" S.S.
CONST. MANHOLE
INSTALL 18" S.S.
INSTALL BY BORE
INSTALL 18" S.S.
CONST. MANHOLE
INSTALL 18" S.S.
CONST. MANHOLE
NOTE: Trench shield(s) and/or slope (Option I or II) shall be used for personnel protection at the
location o£the bore pits. lftrench shields are employed, end protection shall be accomplished
with appropriately rated trench shields or interlocking shcet pile (PZ-27 or equal installed
horizontally). These members shall be installed so as to rest on thc ends of the main trench
shiclds.
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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(5) feet in depth shall also be
~ffectively protected when examination of ground indicates hazardous ground movement
m~O, be expected.
The Contractor will have Options I, I1 for providing such protection.
5.2.2
5.2.3
5.2.4
Lateral Earth Pressure: P - We(H+Hq)
Assumed Soil: Clay
a uniibrmly distributed lateral soil pressure, m lbs./ft2
We Effective Soil Weight, pcf(Use 45 psfType"B" Soil)
H Depth of excavation from top of supported bank to
bottom of excavation in feet.
Ilq Equivalent Height of Surcharge, in feet.
Reference OSHA Rules and Regulations-Part 1926 of 29 CFR
as amended by the Federal Register Volume 54, Number 209,
October 31, 1989
T~ WE 45
H
Maximum anticipated lateral earth pressure for this project is 1035 "PSF"
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
rcstrictions may limit the use of this option. See Drawing Option 1.
Option 11 The Contractor may use a Trench Shield as shown in the Option II section of
this specification. Requirements sct forth in this Option shall include curricular trench
shield(s) and or manhole boxes. All slopes above trench shield(s) shall conform to
guidclines set forth iu Option 1. 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 11.
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TRENCH SA FE TY SPE CIFICA TIONS
OPTION I
H/V - REQUIRED SLOPE PER SOIL TYPE
H/V ~4 to 1
H/V 1 to 1
}-I/V - 1V~ tol
H/V-.-2 tol
Stiffclay less than 12 feet in depth (Type "A")
Stiff clay or weathered limestone (Type "A" or "B")
Silty clays or saturated material (Type "C")
Fill material or loose soil.
NOTES
1. All trenches shall be dcwatered as specified in 4.5.7
2. All slopes assume sufficient right-of-way exists.
3. All slopes shall be flattened an additional V2 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 cquipment shall be permitted nearer thau 2 feet from the edge of the excavation.
5. A single 3' 6" vertical bench may be used in "stiff clay" only.
6. Exposed existing utility lines are to be supported.
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TRENCH SA FE TY SPE CIFIC.4 TIONS
OPTION H
TRENCH SHIELD
Spoil Material
2' Min.
V
H
1' Bench is recommended
?,loped portions of tile excavation shall
begin 18" below the top of the trench
shield(s) and confornr to guidelines
scl fo~tb itl Option I.
Trench shield(s) may be benched 2 feet
I ,II, clay . ~
Requirements and m,,ethods stipulate~tI
herein will apply to manhole boxes
and/or "circular shields" that have been
manufactured for personne protection.
NOTES
I. l'~ench shields shall be inspected and be free of structural defects that nmy impair their proper tiinction.
2, I'rcnch shields shall be used in accordance with the manufacturer's guidelines and recommendations.
3. I'rcnch shields sball be installed so as to prevent any lateral or other hazardous movement.
4, Personnel shall not bc allowed in the trencb shield during its installation or removal fi-om the excavation.
5, When shield(st arc stacked, thc upper shield shall be rated lbr 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
o['cttt indicated below, Manuthcture's tabulated data or certification shall be maintained on site.
II00
1000
900
800
7O0
600
500
400
300
5 l'cct 7.5 Feet 10 Feet 12.5 I:cct 15 Feet 17.5 Feet 21 Feet
10