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WA9601A-SP 990105 TRENCH SAFETY - SPECIFICATIONS FOR THE SANDY LAKE ROAD - WATER LINE CITY OF - COPPELL, TEXAS Prepared for FOX CONTRACTORS TREN- TECH COMPANY coPeEft, rtx4s 7sos9 .--.5,~. 9 72-3 04-21 71 I ~"~/:~:.' ....223~9.. ..... ,o~..% ~.~-';~7 I have reviewed these Trench Safety Guidelines and find that the recommendations and procedures conform to OSHA guidelines and regulations. The calculations herein are consistent with generally accepted engineering practice. e=. I-5-99 REGISTERED PROFESSIONAL ENGINEER DATE -- Entire contents copyright © by Tren-Tech Company. All rights reserved ~pro~.c,,on ,.~ho,eor ,np~r,~,,ho.,,~.m,ss,on ,sproh,~,,.~qC, O t'~ 1.0 DESIGN ASSUMPTIONS -- 1.1 General. These specifications cover the basic requirements for shoring and/or sloping of excavations for the installation of WATERLINES for the SANDY LAKE ROAD 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. 1 Copyright © 1993 by Tren-Tech Company 2.0 DEFINITIONS ' 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"- 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 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, fabrication, 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 3.1.70SHA 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 © 1993 by Tren-Tech Company 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. 4.3.1 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 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). 3 -- Copyright © 1993 by Tren-Tech Company 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 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 6fthe 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 -- Copyright © i993 by Tren-Tech Company 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 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 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 be taken. 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. -- COpyright © 1993 by Tmn-Tech Company - SECTION 5.0 SITE SPECIFIC EXCAVATIONS - AND SHORING SPECIFICATIONS FOR WATER LINES -- Copyright © 1993 by Tren-Tcch Company 5.1 EXCAVATIONS SPECIFIC TO THIS PROJECT -- 24" WATER LINE LOCATION MAX. DEPTH OPTION NOTES ' 2+15.30 TO 8+25 10.0 I, II INSTALL 24" W.L. 8+25 TO 8+55 INSTALL BY BORE ' 8+55 TO 9+50 10.0 I, II INSTALL 24" W.L. 9+50 TO 9+80 INSTALL BY BORE 9+80 TO 65+83 15.0 I, II INSTALL 24" W.L. 65+83 TO 66+70 INSTALL BY BORE 66+70 TO 76+00 12.0 I, II INSTALL 24" W.L. 95+51.41 TO 96+90 10.0 I, II INSTALL 24" W.L. 96+90 TO 97+25 INSTALL BY BORE 97+25 TO 107+70 15.0 I, II INSTALL 24" W.L. 107+70 TO 108+00 INSTALL BY BORE 108+00 TO 109+20 11.0 I, II INSTALL 24" W.L. 109+20 TO 110+00 INSTALL BY BORE _ 110+00 TO 115+40 11.0 I, II INSTALL 24" W.L. 115+40 TO 117+29 INSTALL BY BORE -- 117+29 TO 117+86.74 15.0 I, II INSTALL 24" W.L. -- NOTE: Trench shield(s) and/or slope (Option I or II) shall be used for personnel protection at the location of the bore pits. -- Copyright © 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(5)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 for providing such protection. _ 5.2.2 Lateral Earth Pressure: P = We(H+Hq) Assumed Soil: Clay _ P= a uniformly distributed lateral soil pressure, in Ibs./ft2 Hq ~ We= Effective Soil Weight, pcf(Use 45 psfType"B" Soil) DV ~ H= Depth of excavation from top of supported bank to bottom of excavation in feet. . WE 45 ' Hq= Equivalent Height of Surcharge, in feet. H Reference OSHA Rules and Regulations-Part 1926 of 29 CFR JC as amended by the Federal Register Volume 54, Number 209, -- October 31, 1989 Maximum anticipated lateral earth pressure for this project is 765 "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. Option I is normally not permissible in paved street areas. 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. 8 Copyright © 1'993 by Tren-Tech Company - TRENCH SAFE TY SPE CIFICA TIONS OPTION I  SpoilMateri~,,oi ~,~dgSLOPE - H/V - REQUIRED SLOPE PER SOIL TYPE H/V = '//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 ~ tol Silty clays or saturated material (Type "C") 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 flaRened an additional ½ 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 may be used in "stiff clay" only. 6. Exposed existing utility lines are to be supported. 9 -- Copyright © 1993 by Tren-Tech Company TRENCH SAFE TY SPECIFICATIONS OPTION II TRENCH SHIELD _ Spoil Material ~ -- 1' Bench is recommended Vi H -- Sloped portions of the excavation shall begin 18" below the top of the trench shield(s) and conform to guidelines Requirements and methods stipulated _ set forth in Option I. herein will apply to "manhole boxes" and/or "circular shields" that have been Trench shield(s) may be benched 2 feet manufactured for personnel protection. -- in "stiff clay". - NOTES 1. Trench shields shall be inspected and be flee 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. 800 ..................... 7 0 0 _ 600 500 -- 400 ..... 300 5 Feet 7.5 Feet 10 Feet 12.5 Feet 15 Feet 10 __ Copyright © 1993 by Tren-Tech Company