Forest Cove 1-SP 980211 TRENCH SAFETY
SPECIFICATIONS
FOR
FOREST COVE ESTATES
PHASE 1
CITY OF
COPPELL, TEXAS
Prepared for
SITE CONCRETE
TREN- TECH COMPANY
828 HO,,'ELL DR. .~'~,<,?..~. .....
COPPELL, TEXAS 75019 ~ o ..: ~.'.~..':,~ '..? ~.
972-304-2171
I WILLIAM p. ~"iC~ ....
~, o".~. "¢~ -'~,~
~ ~,,,,e rc¥ic,~'c.~ this'rrenc~ Safe~.-~'l,,n a.d nua t~at its reeommen.~.,o.s and
procedures conform to OSHA guidelines and regulations. The calculations
herein are consistent with generally accepted engineering practice.
REGISTERED PROFESSIONAL ENGINEER DATE
Entire conte.t~ COl~vrtghl ~ 1993 by l?en-Tech C'ompany. . tll right.* re.sero'ed
Reproduction ltl whole or ltl part Wll/IOll/ permmwon I.v ])rohtbtted
1.I General. These specifications cover the basic requirements for shoring and/or sloping of
excavations for the installation of SANITARY SEWER LINES. WATERLINES, and
STORM SEWER LINES tbr FOREST COVE ESTATES - PHASE I 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, the3-' shall conlYrm to the high standards of
engineering and of sate trench excavation.
1.4 The personnel protection systems shoxYn in these specifications have been designed based
on information obtained from the project dra~vings 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 sy.'stem option shown
in these specifications, depending on trench depth and soil conditions.
1.7 The protection of existing structures and utilities xYhich may be affected by these trench
excavations is beyond the scope of this report (See Sect.4.2)
1.8 The Contractor must identit\~ a "Competent Person" in the Contractor's firm responsible
tbr 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 xvithin 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 O~-ner's failure to note exceptions to
these specifications shall remain the sole responsibility and liability of the contractor.
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Copyright t., 1993 by Trcn-'l-ech Company
2.1 All definitions of section 1926.653 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"- I'he engineer whose Texas seal is affixed to these
specifications.
2.3 "The Contractor"-The contractor responsible to the owner tbr the excavation work
described herein.
2.4 "Competent" as described in OSHA 1926.650(b).
3.0 APPLICABLE CODE AND STANDARDS
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, thbrication, 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 Unilbrm 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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Copyright (~ 1993 by Tren-'l'cch Company
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 otherx¥ise be affected b5.' the proposed
trenching operation, the Contractor shall provide adequate protection by the use of
sheeting and shoring to protect the structure, street, or highway t¥om possible
damage. In the case of utilities, the Contractor may elect to remove the ufilit,'.
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 responsibilit5- 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 satiety 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 contbrm
to the requirements listed in this specification.
4.3.1 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 bra
"Competent Person" to ensure that trench excavation has been pertbrmed 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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Copyright ~' 1993 by 'Iren-'I-ech Compan.~
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. Daily inspections of the excavations shall be made by the Competent Person". If there is
evidence of possible cave-ins or slides, all x~'ork 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 thlling 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 d~-ing, water, or I'reezing.
4.5.7 Water shall not be permitted to stand in thc 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 bc revised.
4.5.10 Remove shoring units from bottom to top as backfilling proceeds.
4.5.11 When backfill is ~¥ithin five(5) feet of the top of the trench, all shoring may be removed.
unless the trench conditions indicate a hazard.
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Cop3 righl C 1993 b.~ Tren-Tcch C'ompan.,,
4.5.12 No person shall be exposed to the lower portion of the trench after shoring has been
removed.
-- 4.5.13 Additional shoring of larger sizes ma3-' be installed.
4.5.14 kadders 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 t~vo(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 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 tbr 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 be taken.
4.6.3 Retesting of work areas shall be conducted as often as necessary to ensure that the
atmosphere remains sate 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 folloxving 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 (,' 1993 by 'l'ren-'Iech Company
SECTION $.0
SITE SPECIFIC EXCAVATIONS
AND
SHORING SPECIFICATIONS
FOR
SANITARY SEWER LINES
WATER LINES
AND
STORM SEWER LINES
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Cop,x right ',5 1993 b.x 'l'ren-'rcch Compan.x
5.1 EXCAVATIONS SPECIFIC TO THIS PROJECT
__ SANITARY SEWER LINE "A"
LOCATION MAX. DEPTI t OPTION NOTES
- 1-38.60 TO 2-20.44 5.5 I. II. III INSTALl. 8" S.S.
2*20.44 6.5 I. Ii CONST MANHOLE
2+20.44 TO 4 .~3 9.5 I. II. III INSTALL 8" S.S.
44-35 10.5 I. Il CONST MANHOLE
4-35 TO 8 .~0 9.5 I. II. Ill INSTALL 8" S.S.
8+30 7.0 I. I1 CONST MANHOI.E
8+30 TO 9-57 7.5 I. II. III INSTALL 8" S.S.
SANITARY SEWER I.INE "B"
LOCATION MAX. DEPTH OPTION NOTES
1-00.39 4.0 I CONST MANHOLE
1-~00.39 'l'O 2.-60 7.0 I. Il. II1 INS'FALL 8" S.S.
2+60 8.0 I. Il CONST MANHOLE
2+60 TO 7+60 8.5 I. II. III INSTALL 8" S.S.
74-60 9.5 I. II CONST MANI-tOLE
74-60 TO 10+87 8.5 I. II. 1II INSTAI.L 8" S.S.
10+87 7.0 I. II CONST MANHOI..E
SANI-I'ARY SEWER kINE "C"
-- LOCATION MAX. DEPTH OPTION NOTES
1+00 TO 3+22 8.5 I. Il. III INSTALl. 8" S.S.
__ Copsright C 1993 b5 Tren-'l'cch Company
STOtLM SEWER LINE "A"
-- LOCATION MAX. DEPTH OPTION NOTES
1-00 TO 1+98 7.0 I. II INSTALL 27" RCP
-- 1+98 TO 3-33.38 7.0 I, II INSTALL 24" RCP
STORM SEWER LINE "A- 1"
LOCATION MAX. DEPTH OPTION NOTES
1.-00 TO 3.-39.63 7.0 I. II. III INSTALL 18" RCP
STORM SEWER LINE "B"
LOCATION MAX. DEPTH OPTION NOTES
0+92 TO 1+22 5.0 I. Ii INSTALl, 30" RCP
1-22 TO 8+39.70 5.5 I. II INSTALL 24" RCP
SIORM SEWER LINE "C"
LOCATION MAX. DEPTH OPTION NOTES
1+00 TO ?55 5.0 I. II INSTALL 27" RCP
PROJECT WATERLINES AND APPURTENANCES
The contractor is required to install various water lines on the project. No profiles Ibr these
various waterlines were provided on the project plans, however, it is doubtful that excavation
depths greater than five feet will be necessarv and therefore shoring mav not be required. If
excavation depths greater than five feet are encountered or if there is evidence of raveling or
caving for any reason including pre-disturbed soil conditions, the contractor will be required to
shore or slope the excavation so as to provide a safe workplace. The contractor max-use
guidelines set forth in Option 1. II or 11I tbr these excavations.
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Copyright ~7 1993 by 'l'ren-Tcch Compan.x
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 xvhere employees may be exposed
to moving ground or cave-ins. Trenches less than five(51 fi~et in depth shall also be
effectively protected when examination q/'ground indicates hazardous ground movement
-- may be expected
The Contractor ,,,,'ill have Options I. II or III for providing such protection.
5.2.2 Lateral Earth Pressure: P = We(H+Hq)
Assumed Soil: Clas-' IIq I< I
P~ a uniformly distributed lateral soil pressure, in lbs.:fi-'
'¢,"e= Effective Soil Weight. pcf(Use 45 psfType"B" Soil) ]
H= Depth of excavation from top of supported bank to < WE 45
-- bottom of excavation in feet. 1t
Hq= Equivalent Height of Surcharge. in feet. I <
Reference OSHA Rules and Regulations-Part 1926 of 29 CFR
-- as amended by the Federal Register Volume 54. Number 209.
October 3 I. 1989
Maximum anticipated lateral earth pressure for this project is 562.5 "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 Ibur(4) feet. Easement
restrictions may limit the use of this option. Option I is normally not permissible in
paved street areas. See Drawing Option I.
5.2.4 Option II The Contractor may use a Irench Shield as shown in the Option I1 section of
this specification. Requirements set tbrth in this Option shall include curricular trench
shield(s) and or manhole boxes. Ali slopes above trench shield(s) shall contbrm to
guidelines set forth in Option 1. Trench shield(s) used on this prqiect 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 I)rawing
Option Il.
5.2.5 Option II1 Ihe 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 ,,,`-all. the contractor shall install ply,~vood
behind the shores as shown on the Option Ill drawing.
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-- Copyrigh! C 1993 b.~ Tren-Tcch Company
TRENCH SA FE TY SPE CIFICA TIONS
OPTION I
Material ~'
spoi~ ~ SLOPE
31~';~'iendglne sti~12~-~ 0.~ ~ehnec~;~t~;tt;ro~noa~"Us~;;he'e'.
H/V- REQUIRED SLOPE PER SOIL TYPE
It/V = 3A to 1 Stiffclay less than 12 feet in depth (Type "A")
. "\ .... B")
H."'V = 1 to 1 Stiffclav or weathered limestone (Tvpe ..' or
H/V = 1 V2 tol Silty clays or saturated material (Type "C")
H.."V = 2 to I 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 V: 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" verlical bench may be used in "stiffclav" only.
6. Exposed existing utility lines are to be supported.
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Copyright ( 1993 by 'Den- [cch (_'ompan.~
TRENCH SA FE TY SPE CIFICA TIONS
OPTION II
TRENCH SHIELD
Spoil Material
1' Bench is recommended
Sloped portions of the excavation shall
:::3~1.::~5s) may_be benched- feet 5 }~~¢ :~ manulhctured for personnel protection.
NOTES
1. Trench shields shall be inspected and be ~ee of structural detects that may impair their proper function.
2. Trench shields shall be used in accordance with the manuhcturer's guidelines and recommendations.
3. Trench shields shall be installed so as to prevent an3 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. lrench shield(s) used on this project shall be rated to withstand anticipated "PSF" (left side of graph) for depth
of cut indicated beloa'. Manufacture's tabulated data or certification shall be maintained on site.
600
500
450
400
350
300~
5 ~eet 7.5 Feet 10.5 Feet
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Copyright (' 1993 by Trcn-'l'¢ch Company
TRENCH SA FE TY SPE CIFICA TIONS
OPTION III
SHORING
I
i
] . '
shores to prevent raveling.
NOTES
1. Shores shall be double stacked when trench depths exceed nine (% feet.
2. Maximum horizontal spacing for double stacked shores shall be fix-e (5) feet.
3. Maximum allo~vable depth of cut for this Option shall be fourteen (14) feet.
4. Aluminum hydraulic shoring ma5' 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 ofshores in lype "B" soil shall be 5 feet.
7. The contractor's competent person shall inspect shores and verify that they are in good x-¥orking 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 I 's" thick plywood or %" thick
14 ply arctic white birch (Finnland tbrm}.
I I. Spoil material will not be allowed nearer than 2' from the edge of the excavation
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Copyright t' 1993 by Tren:l'ech C'ompan.x