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Freeport NIP(6)-SP 980309John Skinner PATCO UTILITIES, INC. 1617 W. Highway $03 Grand Prairie, Texas 75051 (214) 641-7901 FAX (214) 641-8253 EXCAVATION SAFETY SPECIFICATIONS FOR STORM DRAIN WATER LINE SANITARY SEWER TO SERVE FREEPORT NORTH DISTRIBUTION CENTER MEPC American Properties CITY OF COPPELL, TEXAS Contractor: Patco Utilities, Inc. 1617 W. Hwy 303 Grand Prairie, Texas March 1998 File No. 98312 M.W. Custer, P.E. 5006 Oak Springs Dr. Arlington, Texas 76016 817483-5579 1.0 DESIGN ASSUMPTIONS 1.1 General. These specifications cover the basic requirements for shoring and/or sloping of excavations for installation of Storm Drain, Water Line and Sanitary Sewer for the Freeport North Distribution Center Project, 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. 1.5 The personnel protection systems shown in these specifications have been designed based on an assummed subsurface of Type A and Type B Soils. In accordance with Revised OSHA (effective March 2,1990), prior to beginning construction, The contractor's "Competent Person" will conduct the required Soil Classification Tests. If soils other than those 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 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. 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. If conditions in the field vary from the expected conditions, the design engineer shall be contacted, for possible design modifications prior to personnel entering the excavation. 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 0. S.HA. Any property damage or bodily injury (including death) arising from the use of these specifications, from 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. 2.0 3.0 4.0 DEFINITIONS 2.1 2.2 2.3 2.4 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. "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). APPLICABLE CODES 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 3.1.2 3.1.3 3.1.4 3.1.5 3.1.6 3.1.7 OSHA 2207, Construction Industry Standards(part 1926 Occupational Safety and Health Standards) AISC Code of Standard Practice AISC Specification of the design, fabrication, and erection of steel buildings. AITC Timber Construction Manual AWS D1.1 Structural Welding Code The Uniform Building Code OSHA 2226 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. SHORING/SLOPING REQUIREMENTS 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 meets with the approval of the engineer, the utility owner, or whoever has jurisdiction of the structure. In all 4.0 SHORING/SLOPING REQUIREMENTS Cont'd. 4.3 4.4 4.5 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. 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 1926.50 and 1926.651 of Subpart P, Part 1926, of the Code of Federal Regulations shall be by reference an integral part of this section. Requirements Prior to Excavation Activities. 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 O.S.H.A. requirements and to ensure that no anomalies are observed which may effect the safety of the trench or project. Note -This person must be "Competent" as described in OSHA 1926.65(b). Requirements During Excavation Activities. 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 project. 4.5.2 Daily inspections of the excavations shall be made by the Contractor's "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 (b). 4.0 SHORING/SLOPING REQUIREMENTS Cont'd. 4.5.3 Excavations shall be inspected after every rainstorm or other hazard- increasing occurrence to ensure the safety of the workmen and the trench. 4.5.4 Excavated material shall be stockpiled a distance away from the trench, so as not to affect the trench stability. The contractor's construction 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. 4.5.5 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. 4.5.6 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. 4.5.7 The Contractor must take precautions to protect the face of the excavation from exposure to freezing. 4.5.8 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. 4.5.9 The Contractor shall provide a positive means of ensuring that hydrostatic pressure does not build up behind the shoring or shields. 4.5.10 If a condition requiring the use of a different method of shoring is encountered, this specification will be revised. 4.5.11 Remove shoring units from bottom to top as backfilling proceeds. 4.5.12 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. 4.5.13 No person shall be exposed to the lower portion of the trench after shoring has been removed. 4.5.14 Additional shoring or larger sizes may be installed. 4.5.15 Ladders or other adequate means of exit must be provided and located so as to require no more than 25 feet of lateral travel. 4.0 SHORING/SLOPING REQUIREMENT S 4.5.16 When two trenches intersect, both trenches must be protected to a distance of not less than the depth of the deepest trench. 4.6 Shoring Alternatives for this Work 4.6.1 Trenches more than 5 feet 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 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 for providing such protection. 4.6.2 Lateral Earth Pressure P= a uniformly distributed lateral soil pressure, in lbs./fi.2 We= Effective Soil Weight, pcf H= depth of excavation from top of supported bank to bottom of excavation, in feet. Hq= Equivalent Height of Surcharge, fi. P= We*(H+Hq) (Reference OSHA Rules and Regulations-Part 1926 of 29 CFR as amended by the Federal Register Volume 54, Number 209, dated October 31,1989.) 4.6.3 4.6.5 4.6.6 4.6.7 Option I The contractor can use Slope as shown in the Option I section of this specification. See Drawing 1 and General Notes-Slope Option II The contractor can use Trench Shield as shown in the Option II section of this specification. See Drawing 2 and General Notes-Shields Option IIa For BORE / EXIT Pits- The contractor can use Trench Shield as shown in the Option IIa section of this specification. See Drawing 3 and General Notes-Shields Option III The contractor can use Trench Shores as shown in the Option III section of this specification. See Drawing 4 and General Notes-Trench Shores GENERAL NOTES -Slope 1 .) A maximum allowable slope of 1.0 (horizontal) to 1.0 (vertical) may be used during trench excavation in soil materials in lieu of trench shoring systems. Soil materials that could be sloped to this configuration include clayand sandy clay. This temporary slope configuration represents the steepest incline for short-term conditions (a time period less than 72 hours) that is acceptable given probable but subjective influences from rainfall and normal equipment vibrations. However, if during excavation or construction of this project there is any indication of general or local instability, slopes shall be cut back to a slope which is at least 0.25 (horizontal) to 1.0 (vertical) flatter than the specified slopes outlined previously, i.e., this translates to a total slope of 1.25 (horizontal) to 1.0 (vertical). This flattening of the slopes may be required due to the deterioration of the shear strength with time or due to trench flooding, instability induced from excessive adjacent vibrations (resulting from equipment operation), excessive adjacent surcharge loads due to equipment or stockpiled excavated materials, shrinkage cracks due to drying, etc. 2.) Additional flattening of slopes is required when any of the following conditions are present; 1 .) Slopes in soft loose soils or fill materials shall be flattened to 2:1 2.) If an existing parallel utility line is located within a horizontal distance equal to the depth of the new utility excavation, all slopes shall be flattened an additional 0.5:1. 3.) Contractor's "Competent Person" shall monitor the excavation to evaluate subsurface conditions and determine soil type and condition. When contractor's "Competent Person" cannot assure that the slope is suitable for safe use, a qualified soils engineer shall be consulted. GENERAL NOTES-Trench Shields 1.) 2.) 3.) A Trench Shield is a structure that normally will not prevent a cave-in, but is able to withstand the forces imposed on it by a cave-in and thereby protect workers within the structure. Trench Shields are also referred to as "Trench Boxes". These general notes also are applicable to Manhole Shields. A "Pre-manufactured Shield" is a product designed, constructed and marketed to the construction industry as a method of protecting personnel while working in trenches subject to cave-ins. A "Shop-built Shield" is defined herein as a shield built by a contractor or his agent for their own use as a personnel protection device and is not available commercially as a product to the construction industry. GENERAL NOTES-Trench Shields cont'd. 4.) 6.) 7.) 8.) 9.) Acceptable Shield Systems: Pre-manufactured shields are commercially available and may be used provided that the shields are selected and used in accordance with the manufacturer's specifications, recommendations and limitations. Deviations from manufacturer's specifications, recommendations and limitations will not be allowed without the manufacturer's specific written approval. This specific written approval of deviations must be kept at the jobsite along with the manufacturer's specifications and recommendations for use and other instructional use literature for the specific shield. Shop-built shields may be used, when designed and sealed by a professional engineer registered in the state of Texas and having a background in the practice of structural engineering. All shields must be free from damage or defects that might impair their proper function. Shields shall be used and maintained in a manner consistent with the recommendations of the manufacturer or design engineer. Damaged shields shall be removed from service until authorized repairs are made. Shields shall be installed in a manner which restricts lateral or other hazardous movement of the shield in the event of the application of sudden lateral loads. Where trench shields are stacked, a mechanism must be available for connecting the shields to prevent differential movement between the shields when subjected to laterals. Benching of earth material below the bottom of the shield is allowed to a maximum of 2.0 ft., when this benched material is of sufficient strength to support the shield. Workmen shall not be allowed in shields when shields are being installed, removed or moved vertically. A ladder or other safe means of entry and exit shall be located such that workmen are not exposed to a potential cave-in hazard during entry or exit from the shield. Shields shall be used such that excavated soil, rock or other debris can not fall or roll into the trench shield. In vertical trenches, the shield should rise a minimum of 1'-6" above the ground surface. In situations where a slope is constructed above the top of the shield, the top of the shield should extend a minimum of 1 '- 6" above the point at which the slope begins. In addition, the contractor shall be responsible for removal of soil which may slide into the trench or against the trench shield and for replacing these materials in accordance with backfill specifications. GENERAL NOTES-Trench Shores l.) Aluminum Hydraulic Shores are a product designed and manufactured as an alternate to timber shoring in order to provide a light weight product capable of being installed and removed without entering the trench. 2.) Aluminum Hydraulic Shores shall be designed and manufactured so as to comply with OSHA regulations and provide strengths of the vertical rail and hydraulic cross-brace which are not less than a timber bracing system which would be required under the same loading condition. The manufacturer must have complete design calculations on all system components and shall make this information available to the Owner. The following minimum requirements shall be met by the manufacturers' product: a. Vertical rails shall have a minimum width of 8 inches and have an equivalent strength in bending of not less than that of a 3" by 10" No. 2 Douglas Fir timber with its' wide side to the trench wall. The rail must be capable of having plywood attached to it, if necessary. b. The hydraulic cross-braces shall be minimum 2-inch I.D. and capable of sustaining a axial force of not less than 20,000 pounds at al .50 safety factor at 50% extension. c. Aluminum oversleeves shall be used in accordance with the manufacturer's recommendations. Extensions shall not be used unless approved in writing by the manufacturer. d. Hydraulic pumps shall be equipped with calibrated gauge having a minimum operating range of 750-1500 psi. e. All other accessories and specialty tools shall be furnished and used as per the manufacturer's recommendations. 3.) The vertical rails, hydraulic cylinder cross-braces and all other components of the systems shall be in good, serviceable condition and without damage or defects which would prohibit proper use. The hydraulic system shall not exhibit leaks or pressure loss or otherwise indicate the possible loss of system pressure while in use. Damaged components pr improperly operating equipment shall be removed from service. The contractor's "Competent Person"shall be responsible for making these inspections and determinations. Alterations to shoring components shall not be allowed unless permitted in writing by the manufacturer's authorized agent. 4.) Plywood, used in conjunction with hydraulic shores, shall meet the following requirements: a. Softwood plywood must be 1 1/8" minimum thickness, exterior grade quality, CDX grade or better. b. Hardwood plywood must be 3/4", minimum thickness, Arctic Birch plywood. "FinnForm" brand or equal, 14 ply-all hardwood. Plywood which is broken, bent, frayed or otherwise deformed and unsuitable for its intended purpose shall be replaced. 10 GENERAL NOTES-Trench Shores cont'd. s.) The contractor shall install aluminum hydraulic shores in accordance with these specifications and the manufacturer's specifications, instructions, recommendations and limitations. The recommended shore lengths and spacing are shown in these specifications. The contractor may decrease the spacing to provide additional lateral support if so required by site observations. The contractor's "Competent Person" shall insure that the workmen installing, removing and working around the shoring have been adequately trained in the proper procedures for their installation, safe use and removal. 6.) Hydraulic shores shall be installed flush against the trench walls such that the vertical rails have uniform support. The top hydraulic cylinder must not be located above the existing ground surface. The hydraulic cylinders shall be pressurized to a normal working range of 750-1000 psi. 7.) The contractor may at his discretion utilize shorter rails in order to accommodate those situations such as backfilling where the trench depth becomes to shallow for use of the standard 7-foot vertical rail. The shorter aluminum hydraulic shores must meet or exceed all of the specification requirements herein. 8.) Plywood shall be attached to the vertical rails and used in this manner any time there is evidence of raveling, sloughing or caving which cannot be adequately shored by skip- shoring. In particular, plywood backing will be necessary when shoring cross-trenches, when excavating in previously disturbed soils, and at those locations as indicated in these specifications. 9.) The contractor may at his discretion temporarily remove shoring to expedite the installation of piping provided that workmen are not located in the unshored trench and provided that the shoring is properly replaced. 10.) While backfilling the trench, the contractor shall maintain the stability of the trench walls by adjusting the location of the shores vertically such that workmen can safely place and compact the backfill materials. Workmen shall not be in a position to be endangered by this adjustment procedure. 11.) The contractor may remove the hydraulic shores from the trench during backfilling operations provided the following conditions are met: a. Backfilling is performed by mechanical devices which do not require that workmen be in the trench. b. The trench walls maintain their shape without sloughing. c. The removal of the hydraulic shores does not endanger adjacent structures, roadways or utilities. 11 5.0 EXCAVATIONS SPECIFIC TO THIS WORK Location Max. Depth Options Notes Storm Drain 1+00 to 1+62.41 12.0 I or II 1+62.41 to 5+35.63 10.5 I or II 5+35.63 to 8+68.59 8.5 I,II or III 8+68.59 5.0 I or II Install 36" RCP Install 30" RCP Install 24" RCP Install Inlet Lat E-1 1+00 to 1+32.5 9.0 I,II or III Install 24" RCP Lat. E-2 1+00 to 1+49.64 9.0 I,II or III Install 24" RCP Lat. D-1 1+00 to 1+24 9.0 I,II or III Install 24" RCP Along South Side Project ~ Exist Connect to exist 6.0 I or I1 Connect to exist. 6.0 I or II Com~ect to exist 6.0 I or I1 Install 10' Inlet Install 6' Inlet Install 4' Inlet Water Line Along South Side Project 9.0 I,II or III Install Fire Hydram Line F 1+00 to 2+25 9.0 I,II or III Install 3" WL Near Above Loc. 9.0 LII or III Install 125 LF 8" Fire Line Line E 1 +00 9.0 I,II, IIa or III Install 152 LF 6" WL (75' by bore) Line D 1+00 9.0 I,II, IIa or III Install 120 LF 6" WL (75' by bore) Line C 1+00 9.0 I,II or III Install 55 LF - 6" WL Line B 1 +00 9.0 I,II, IIa or III Install 116 LF 6" WL ( 76' by bore) Sanitary. Sewer Line A 1+00 to 1+43 10.0 I or IIa Bore for SS ACTIVE PRESSURE CALCULATION SUN/VLARY CASE: Patco Utilities, Inc. Input File = UNTITLED.APR Time: 09:33:39 Date: 03-09-1998 Total active pressure = 3741.26 With angle from horizontal = 0.00 Failure surface from horizontal = Total soil weight in failure zone = Total surcharge load in failure zone = Soil resistance along failure surface = with angle from horizontal =59.90 Pressure at wall base = 623.54 Pressure at wall base along horizontal = Pressure at wall base along vertical = coeficient of active pressure Ka = 0.43 57.10 5589.48 864.47 7459.91 The Height of Wall (H) = ~2.00~attered Angle of Wall = 0.00 Friction Angle of Wall 0.~0 ~ Friction Angle of Soil = 27.00 Soil Unit Weight = 120.00 Section Slope Angle Length Of Slope No. (deg) S 1 0 48 Distributed Left Point Left Load Right Point Right Load Load No. X1 Q1 X2 Q2 Depth Is Measured From Ground Surface ***************************************************************** Force -- lp/ft Pressure -- psf Length ~ ft TS.O' Max. 2.0' Max. < /~poil or Stockpiled Material ref. general Notes ( 4.6.1 ) Trenches more than 5.0 feet in depth 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 5 feet in depth shall also be effectively protected when examination of ground indicates hazardous ground movement may be expected. Unprotected vertical cut allowed with certain conditions, when depth does not exceed 5.0 feet. _ 12.0' Max~ 2.0' Max. ~.....~ ¢ /Spoil or [ Stockpiled Material ) :(lV) Y OR SANDY CLAY ) WEATHERED LIIVESTONE ORDINARY SLOPE Notes: HA/= Steepest Allowable Sideslope HA/= .75:1 Weathered Limestone HA/= 1:1 Natural Clay or Sandy Clay HA/= 1.5:1 Existing Fills No spoil or equipment neraer than 2.0 feet to edge of excavation. See specification- General Notes Slope for additional requirements. Slope all sides when protecting, structure, manhole or pit excavations. When" Stable Rock" is encountered, the rock may be excavated with vertical sidewalls and slope above the rock. The rock must be "STABLE" as defined in OSHA 1926. When The Contractor's "Competent Person" Cannot Be Assured Of The Soil Type Or Suitable Slope, A Qualified Geotechnical Engineer Shall Be Consulted. This Design Assumes Dewatered Soil Conditions Contractor: Project: Date: Patco Utilities, Inc. Freeport North Dist. Center Coppell, Texas 3110/98 File No. 98312 2.(7< Max~ [ Stockpiled Matedal ~,, 2.0' Bench ./~(1H): (lV) 12.0'Max. '~ / / CLAY OR SANDY CLAY SLOPE WI UNSUPPORTED BOTTOM D1 No Scale Option I SLOPE M.W. Custer, P.E. 5006 Oak Spring Drive Arlington, Texas 76016 817- 48,3-5579 Notes: Use Chart To Determine Minimum Allowable Lateral Bearing Capacity Contractor Shall Make Available Manufacturer's Tabulated Data For Capacity Certification For All Shields Used On This Project Trench Shields May Be Stacked As Required In Stiff Clays Or Rock, The Bottom Of The Shield May Sit On A Bench Not To Exceed 2.0 Feet From The Bottom Of The Excavation Steepest Allowable Slope Above Shields 1H :IV See Specification General Notes- "Trench Shields" For Additional Requirements Example Shield Should "Stable Rock" Be Encountered, The Rock May Be Excavated With Near Vertical Sidewalls And The Shield May Sit Above The "Stable Rock" 1.5' Min. Min. [ Material ~......~ 6" Max. Shields May Be I Stacked As Req'd. Shield May Sit ~ On a 2.0' Bench In Stiff Clay or Rock Shield Extends From Bottom Of Excavation To Surface When The Contractor's "Competent Person" Cannot Be Assured Of The Soil Type Or Suitable Shield, A Qualified Geotechnical Engineer Shall Be Consulted. This Design Assumes Dewatered Soil Conditions Trench Shield Capacity Max. Depth Min. Capacity 12.0' 624 PSF Contractor: Patco Utilities, Inc. 12.0' Max. - ~vated I 2-.0' Min( Material ~ 6" Max. I~///////l Shields May Be Stacked As Req'd. Shield May Sit ~ On a 2.0' Bench In Stiff Clay or Rock Slope Above Shield Project: Date: File No. D2 No Scale Freeport North Dist. Center Coppell, Texas, 983123110198 '/P~!~ Option II Trench Shield M.W. Custer, P.E. 5C06 Oak Spring Drive Arlington, Texas 76016 817- 483-5579 Exam pleStandard Shore Single Stacked Maxim um Horizontal Spacing 6.0 feet Single Stacked Maximum Depth= 9.0' Notes: Use Standard Duty Aluminum Hydraulic Trench Shores as Manufactured by; Speed-Shore Tren-Shore Safe-T-Shore or Equal See General Notes: Trench Shores for additional requirements Plywood Backing Required, when there is evidence of raveling or caving Maximum Horizontal Spacing 4.0 feet Double Stacked Maximum Depth=14.0' Contractor: Project: Date: File No. Parco Utilities, Inc. Freeport North Dist. Center Coppell, Texas 3110198 98312 Example Standard Shores Double Stacked Option III ALUMINUM HYDRAULIC TRENCH SHORES M.W. Custer, P.E. 5006 Oak Spring Drive Arlington, Texas 76016 817- 483-5579