SECTION 31 23 15
SHEETING, SHORING, AND BRACING
PART 1
1.01
GENERAL
SUMMARY
A. Sheeting, shoring, and bracing of trenches and other excavations to protect the Work, as well
as existing property, utilities, pavement, etc., and to provide safe working conditions in the
excavations.
1.02
RELATED SECTIONS
A. The Work of the following Sections is related to the Work of this Section. It is the
Contractor’s responsibility to perform all Work required by the Contract Documents. Other
Sections, not referenced below, may also be related to the proper performance of this Work.
1. Section 01 29 00 – Measurement and Payment
2. Section 01 43 00 – Quality Control
3. Section 31 23 00 – Earthwork
4. Section 31 23 17 – Trench Excavation and Backfill
5. Section 33 80 00 – Landfill Gas Collection System
1.03
REFERENCES
A. The publications listed herein form a part of this Specification to the extent referenced. The
publications are cited in the text by basic designation only. During implementation, the most
recent version of the publication and test method shall be used in all cases.
B. American Institute of Steel Construction (AISC): Specifications for the design, fabrication and
erection of structural steel for buildings (AISC) / IS 800, 9th edition.
C. American Society for Testing and Materials (ASTM) ASTM A36/A36M-08: Standard
Specification for Carbon Structural Steel.
D. ASTM A6 / A6M-10a: Standard Specification for General Requirements for Rolled Structural
Steel Bars, Plates, Shapes, and Sheet Piling.
E. Occupational Safety and Health Administration (OSHA), 29 CFR 1926 PART 1926 – Safety
and Health Regulations for Construction, Subpart P – Excavations.
F. Revised Code of Washington (RCW) Chapter 39.04.180, Public Works: Trench Excavations
– Safety Systems Required.
G. RCW Chapter 49.17 Washington Industrial Safety and Health Act (WISHA).
H. Washington Administrative Code (WAC) WAC 296-155: Department of Labor and Industries,
Safety Standards for Construction Work.
1.04
I.
WAC 296-155: Subsections 650 to 6641: Part N, Excavation, Trenching and Shoring.
J.
WAC 296-155-657: Requirements for Protective Systems.
SUBMITTALS
A. Submit in accordance with Section 01 33 00 – Submittals.
Contract No. SW02-2012
Port Angeles Landfill Cell Stabilization Project
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§31 23 15
Sheeting, Shoring, and Bracing
B. Submit plans showing proposed methods and construction details for all construction
excavations 4 feet or more in depth. The plan shall address both installation and removal of
all required shoring. The plan shall include drawings and calculations prepared by (or under
the direction of) a professional engineer licensed under Title 18 RCW, State of Washington,
and shall carry the professional engineer's signature and seal.
1.05
QUALITY CONTROL
A. Contractor shall perform the Work in accordance with Section 01 43 00 – Quality Control.
B. Construction Quality Control (CQC) refers to those actions taken by the Contractor (including
those parties charged with the manufacture, supply, fabrication, delivery, and installation) to
demonstrate and quantify the characteristics of the product. The results of the CQC program
shall be compared to the Contract Documents and any other contractual or regulatory
requirements.
C. During each aspect of the Work, quality control shall be provided by the Contractor to ensure
that the materials and workmanship conform to the Contract Documents.
D. Contractor shall be responsible for CQC and shall engage and pay for the services of
qualified staff or a qualified subcontractor to perform CQC for monitoring and documenting
the quality of the Work in accordance with the Contract Documents.
E. Any Work that does not satisfy the requirements of the Contract Documents shall be
corrected in accordance with the requirements of the Contract Documents or as approved by
the Construction Manager at the sole expense of the Contractor.
1.06
TRENCH EXCAVATION SAFETY SYSTEMS
A. Protect all utility trench excavation in excess of 4 feet in depth with a safety system
conforming to the referenced requirements.
B. The Contractor’s trench safety system shall be designed by a qualified person and meet the
referenced requirements.
C. All excavation not included in trench safety systems shall also meet the WISHA safety
standards.
1.07
SHORING
A. The Contractor is responsible for the design, installation, and operation of shoring systems to
provide safe work areas in excavations.
B. The Construction Manager is not responsible for suggesting the use of bracing or sheeting, or
a better quality, grade, or section, or larger sizes of steel or timber, or to suggest sheeting,
bracing, struts, or shoring to be left in place.
C. The Construction Manager will not in any way or to any extent relieve the Contractor of any
responsibility concerning the condition of excavation or of any of the Contractor’s obligations
under the Contract Documents, nor impose any liability on the Construction Manager or the
Construction Manager’s agents.
D. Any delays, caused by an action or want of action on the part of the Contractor, or by any act
of the Construction Manager, or their agents, or employees, resulting in the keeping of any
excavation open longer than would otherwise have been necessary, will not relieve the
Contractor from properly and adequately protecting the excavation from caving or slipping.
Contract No. SW02-2012
Port Angeles Landfill Cell Stabilization Project
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§31 23 15
Sheeting, Shoring, and Bracing
E. Any such delays will not relive the Contractor from and of the Contractor’s obligations under
the Contract Documents relating to injury to persons or property, nor entitle the Contractor to
any claims for extra compensation.
PART 2
2.01
PRODUCTS
MATERIALS
A. Wood Materials: Use wood sheeting, sheet piling, bracing, and shoring which is in good
serviceable condition and timbers of sound condition, free from large or loose knots and of
proper dimension.
B. Steel Materials: Steel sheet piling and bracing of equal strength or better may be substituted
for wood.
PART 3
3.01
EXECUTION
GENERAL
A. Sheet, shore, and brace all open excavations where necessary to prevent injury to workmen,
or damage to structures, pipelines, or other features.
B. Used material shall be in good condition, not damaged or excessively pitted. All steel or
wood sheeting designated to remain in place shall be new. New or used sheeting may be
used for temporary work.
C. Timber Used for Breast Boards (lagging): New or used, meeting the requirements of support
design computations in accordance with WAC 296-155-657, the requirements for protective
systems and the approval of the Construction Manager.
D. Steel: Design all steel work for sheeting, shoring, and bracing in accordance with the
provisions of the AISC specifications.
E. Steel Sheet Piling: Manufactured from steel conforming to ASTM A328. Steel for soldier
piles, wales, and braces shall be new or used and shall conform to ASTM A 36. Furnish mill
test reports on new piling but not used ones.
F. Maintain shoring and bracing in excavations regardless of time period excavations will be
open. Carry down shoring and bracing as excavation progresses.
G. Unless otherwise shown, specified, or ordered, remove all materials used for temporary
construction when Work is completed. Make this removal in a manner not injurious to the
structure, its appearance, or adjacent Work.
H. Safe and satisfactory sheeting shall be the entire responsibility of the Contractor.
I.
3.02
Trenching methods and materials shall be as specified in Section 33 80 00 – Landfill Gas
Collection System. Earthwork methods and materials shall be as specified in Section
31 23 00 – Earthwork.
REMOVAL OF SHEETING AND BRACING:
A. Remove sheeting and bracing from excavation unless otherwise approved in writing by the
Construction Manager.
B. Conduct removal such that damage is not caused to the Work.
C. Removal shall be equal on both sides of excavation to ensure no unequal loads on pipe or
structure.
Contract No. SW02-2012
Port Angeles Landfill Cell Stabilization Project
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Sheeting, Shoring, and Bracing
D. Defer removal of sheeting, shoring and bracing, where removal may cause soil to come into
contact with concrete, until the concrete has cured a minimum of 7 days.
3.03
EXAMINATION
A. Examine the site to determine the conditions under which Work shall be performed.
B. Contractor shall formulate his own conclusions as to the extent of the existing subsurface
conditions.
C. Contractor shall be responsible for all trench construction and maintenance, including the
adequacy of trench sheets, shoring, and bracing. Damages resulting from improper sheeting,
shoring, or bracing or from failure to sheet, shore, or brace shall be the sole responsibility of
the Contractor.
D. The method of shoring shall be determined by the Contractor. The Contractor shall install
and maintain shoring, sheeting, bracing, and sloping necessary to support the sides of the
excavation, to keep and to prevent any movement that may damage adjacent pavements,
utilities, or structures, damage or delay the Work, or endanger life and health. The
Contractor may elect to use a combination of shoring and overbreak, sheeting, bracing,
sloping, tunneling, boring, sliding trench shields or other methods of accomplishing the Work,
provided the method meets with the approval of all applicable local, state (WISHA) and
federal safety codes (OSHA).
E. Using skilled labor, drive or set sheeting, sheet piling, braces, or shores in place and
arranged so that they may be withdrawn as the excavations are backfilled, without injury to
piping and structures, and without injury to or settlement of adjacent structures and
pavements.
F. That portion of cribbing or sheeting extending below the springline of rigid pipe or below the
crown elevation of flexible pipe shall be left in place unless satisfactory means of
reconsolidating bedding, or side support disturbed by cribbing, or sheeting removal, can be
demonstrated.
G. The use of horizontal strutting below the barrel of pipe or the use of the pipe as support for
trench bracing shall not be permitted. The bedding or side support shall be carefully
reconsolidated behind the movable box prior to placing backfill.
3.04
SPECIAL REQUIREMENTS FOR HDPE PIPE TRENCHES
A. Shoring to be removed, or movable trench shields or boxes, shall be located at least 2-1/2
diameters away from the pipe if the bottom of the shoring, shield ,or box extends below the
top of flexible pipe, unless a satisfactory means of reconsolidating the bedding, or side
support material disturbed by shoring removal, can be demonstrated.
B. Damages resulting from improper shoring or failure to shore shall be the sole responsibility of
the Contractor.
END OF SECTION 31 23 15
Contract No. SW02-2012
Port Angeles Landfill Cell Stabilization Project
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§31 23 15
Sheeting, Shoring, and Bracing