SECTION TRENCI-JING PART 1 GENERAL

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1 S SECTION TRENCI-JING PART 1 GENERAL 1.1 STIPULATIONS A. The Specification Sections "General Conditions of Contract", "Special Conditions" and "Division 01 - General Requirements" form a part of this Section by this reference thereto, and shall have the same force and effect as if printed herewith in full. 1.2 DESCRIPTION OF WORK A. The Contractor shall furnish all labor, equipment and appurtenances and materials necessary for the excavation of trenches; including but not limited to the installation of sewer lines, utility, lines and other appurtenances in accordance with the Contract Specifications and Drawings, PennDOT Specifications, or as directed by the Using Agency's Representative. 1.3 RELATED SECTIONS A. Section Site Cast-in-Place Concrete B. Section Precast Culvert Steam Tunnel C. Section Aggregates for Earthwork D. Section Dewatering E. Section Sheeting, Bracing, and Shoring F. Section Erosion and Sediment Controls 5 G. Section Public Water Utility Distribution Piping H. Section Sanitary Utility Sewerage Piping I. Section Storm Utility Drainage Piping 1.4 REFERENCES A. Pennsylvania Department of Transportation Specifications, Publication 408, latest edition and subsequent supplements and addendums. B. Final Approved Erosion and Sediment Control Plans and Narrative C. ANSLIASTM D Test Methods for Moisture-Densily Relations of Soils and Soil- Agegate Mixtures, Using 5.5 lb. (2.49 kg) Rammer and 12 inch (304.8mm) Drop. D. Geotechnical Exploration Report (as available) 1.5 SUBMITTALS A. The contractor must submit the sources of supply and cut sheets for backfill materials. 1.6 REGULATORY REQUIREMENTS A. In open trenching or boring on State and/or Local highways, the Contractor shall be governed by the conditions, restrictions, and regulations made by the PennDOT and/or the Local Municipality. Any such regulations shall be considered part of these Specifications. DGS Phase 1.1 TRENCHING I

2 . B. The Contractor shall be responsible at all times for carrying out excavation operations in a safe and prudent manner to protect all workmen and the public from unreasonable hazard. The necessary, sheeting and bracing should be determined in accordance with the field conditions encountered. Applicable OS}-IA requirements must be strictly adhered to. 1.7 EXCAVATION A. Excavation shall be unclassified unless otherwise specified. B. In instances when rock excavation is classified, payment shall be as indicated in the Contract and on the construction plans. 1.8 BLASTING - (Not Applicable) A. Blasting is not permitted. 1.9 WORK DURING INCLEMENT WEATHER A. The Using Agency reserves the right to order cessation of work during inclement weather, if, in the opinion of the Using Agency, the safety of the workman is endangered or if the quality of the work may be affected ACCESS AND INSPECTION A. Work in this section is subject to inspection by the Using Agency or its representative and shall have fill access to the project for the same. PART 2 PRODUCTS 2.1 BEDDING AND BACKFILL MATERIALS A. Type I: Coarse Aggregate Material Backfill - PennDOT 2A Stone. B. Type II: Pipe Bedding - Type A Sand. C. Type III: Backfill - Suitable excavated material free of debris, organic material, and rock larger than three (3) inches. D. Type IV: Pipe Bedding - AASHTO No. 57 Stone. B. All backfill material shall be free from cinders, ashes, refuse, vegetable or organic material, boulders, rocks or stones, frozen soil, slag, or other unsuitable material. When the type of backfill material is not indicated on the plans or is not specified, the excavated material may be used, provided that this material consists of loam, clay, sand, gravel, or other suitable materials. 2.2 CONCRETE BACKFILL A. Where applicable as backfill, concrete shall meet the requirements of Section : Cast-in- Place Concrete for PennDOT Class C. Concrete shall be used to backfill trenches for extending the bearing depth of shallow footings. DGS Phase 1.1 TRENCHING

3 PART 3 EXECUTION 3.1 EXAMINATION A. The Contractor's attention is directed to his responsibilities in accordance with Pennsylvania One-Call utility locations. Any underground utility lines, not limited to those shown on the construction drawings, should be located prior to beginning earth disturbance activities on this site. B. Maintain and protect existing utilities to remain that pass through the work area. C. Before starting any earthwork activity under this Section, the Contractor shall insure that all Erosion and Sedimentation Controls are in place. D. Veri' backfill materials to be used are acceptable. E. Veri& that survey benchnarks and intended elevations for Work are as shown on the Drawings. S 3.2 PREPARATION A. Identif' required lines, levels, contours, and datum. B. Protect plant life and other natural features to remain as part of the post-construction site. C. Protect benchmarks, existing structures, fences, sidewalks, paving, and curbs from excavation equipment and vehicular traffic. D. In the event of property damage, inunediately make repairs and replacements as approved by the possessing party and at no additional cost to the Using Agency. B. Pavement and road surfaces shall be removed as part of the trench excavation. The amount removed shall depend on the width of trench required for the installation of the pipe and the dimensions of the area into which pipes, fittings, manholes, or other structures will be installed. The dimensions of pavement removed shall not exceed the dimensions of the opening required for installation of pipe, fittings, manholes, and other structures by more than six inches in any direction, unless otherwise stipulated in the specifications. Saw cutting shall be used to ensure the breakage of pavement along neat straight lines 3.3 EXCAVATION A. Where trenching occurs through bituminous or concrete pavement, the edge(s) shall first be saw-cut throueh full depth to avoid impacting the remaining edge(s) during excavation. The saw-cuts shall be neat and straight. B. Excavate subsoil required for conduits, sewer piping, manholes, inlets, and other appurtenances. Allow for beddinglsupport depth or the minimum depth as specified on the construction details. Use laser or other Professional-approved method to maintain the grade specified. C. Cut trenches sufficiently wide to enable installation of utilities and al]ow inspection. Refer to the Construction Details, D. Excavation shall not interfere with normal forty-five (45) degree bearing splay of foundations. B. Correct unauthorized excavation at no cost to Using Agency. I. Unforeseen conditions encountered, such as sinkholes, shall be stabilized at a negotiated price. DGS Phase 1.1 TRENCHNG 3)2317-3

4 F. Correct areas over-excavated by error by backfihling with satisfactorily compacted Type I material, at no additional expense to the Using Agency. G. The Contractor shall dewater trenches to provide a dry trench bottom, prior to any installations. Trench water shall be discharged by pumps or by other means to natural drainage channels, storm drains, or other points in accordance with the Final Approved Erosion and Sediment Control Plans and Narrative. Where pumping is required, the Contractor shall provide sufficient pump capacity to maintain the trench bottom in a dry condition. H. Remove excess material not being used to an approved on-site waste area or legally dispose of at the Contractor's expense. 3.4 BEDDING A. For waterline, place six (6) inches of Type IV Material (AASHTO#57) for pipe bedding (pipe cushion). Place materials in 4 inch loose lifts with mechanical tamper or 8 inch loose lifts if vibratory compaction is used. Compact each layer to not less than 97% of the dry weight density of the material, as determined in accordance with the Standard Proctor method (ASTM D 698). The bottom shall be smoothed, leveled and compacted. Form acradle in the bedding material by means of a template conforming to the curvature of the outside surface of the bottom of the pipe, or another approved method, to provide uniform contact under and around the pipe. Bell holes shall be provided so thepipe is unifdrmly supported along its length. After The pipe is satisfactorily laid, backfill ihe french with Type IV Material (AASHTO #57) in 4 inch loose lifts to a height of not less than twelve (I 2) ihche aboi'e thepipe top. Hand work material around pipe haunches and pipe to preclude misalignment and grade changes. Thoroughly compact each layer of backfill with mecháhical tarnpers, or by other acceptable methods for the fill trench vidth. Compact to not less than 100% of the dry weight density of the materill, as determined in accordance with the Standard Proct6i théthod (ASTM D 698). Pipe that is damaged or nidved out of alignment shall be replaced abdlor re-aligned by the Contractor at his expense B. Forsanitary sewer pipes, place six (6) inches of Type IV Material (AASHTO 457) for pipe bedding (pipe cushion). Place materials in 4 inch loose lifts with mechanical tamper or 8 inch loose lifts if vibratory compaction is used. Compact each layer to not less than 97% of the dry weight density of the material, as determined in accordance with the Standard Proctor method (ASTM D 698). The bottom shall be smoothed, leveled and compacted. Form a cradle in the bedding material by means of a template conforming to the curvature of the outside surface of the bottoth of the pipe, or another approved method, to provide uniform contact under and arbundthe pipe. Bell holes shall be ptovided sothe pipe is uniformly supported along its length. After the pipe is satisfactorily laid, backfill the trench with Type IV lvlatërial (AASHTO 457) in 4 inch loose lifts to a height of not less than twelve (12) inches above the pipe top. Hand work mitérial around pipe haunches and pipe to preclude misalignment and grade changes. Thoroughly compact each layer of backfill with mechanical tampers, or by other acceptable methods for the full trench width. Compact to not less than 100% of the dry weight density of the material, as determined in accordance with the Standard Proctor method (ASTM D 698). Pipe that is damaged or moved out of alignment shall be replaced andlor re-aligned by the Contractor at his expense..-' DGS Phase 1.1 TRENCHING

5 C. For storm sewer pipes, place six (6) inches of Type IV Material (AASHTO #57) for pipe bedding (pipe cushion). Place materials in 4 inch loose lifts with mechanical tamper or 8 inch loose lifts if vibratory compaction is used. Compact each layer to not less than 97% of the dry weight density of the material, as determined in accordance with the Standard Proctor method (ASTM D 698). Form a cradle in the bedding material by means of a template conforming to the curvature of the outside surface of the bottom of the pipe, or another approved method, to provide uniform contact under and around the pipe. Hand work material around pipe haunches and pipe to preclude misalignment and grade changes. After the pipe is satisfactorily laid, backfill the trench with Type IV Material (AASHTO #57) in 4 inch loose lifts to a height of not less than twelve (12) inches above the pipe top. Hand work material around pipe haunches and pipe to preclude misalignment and grade changes. Thoroughly cofnpact each layer of backfill with mechanical tampers, or by other acceptable methods for the full french width. Compact to not less than 100% of the dry weight density of the material, as determined in accordance with the Standard Proctor method (ASTM D 698). Pipe that is damaged or moved out of alignment shall be replaced and/or re-aligned by the Contractor at his expense. D. For utilities, place pipe bedding in accordance with the individual utility company's specifications or respective contract drawings. The CONTRACTOR shall coordinate with the utility companies as to the applicable installations. 3.5 BACKFILLING A. Backfill trenches to contours and elevations with unfrozen materials of the SPECIFIED type. B. Do not backfill overporous, wet, frozen or spongy subgrade surfaces. C. Employ a placement method that does not disturb or damage pipe in trench. D. Backfill ABOVE twelve (12) inches over Pipe: Place materials in 4 inch loose lifts with mechanical tamper or 8 inch loose lifts if vibratory compaction is used. 1. Backfill trenches as described in the Construction Drawings. a. Under paved areas, backfill shall consist of Type 1 Material (PennDOT 2A). Compact to 100% of the determined dry weight density of the backfill material. b. Under unpaved areas, backfill shall consist of Type III Material (Suitable Material from Excavation). See Section 3.7 for compaction. E. Refer to Sub-Part 2.1 for material specifications. F. Maintain optimum moisture content of backfill materials to attain required compaction density. G. Remove surplus backfill materials from site as directed by the Professional, if applicable. H. For pre-cast concrete steam tunnels, backfill per the recommendations of the manufacturer. If the manufacturer does not speci' recommendations, backfill with suitable Type III material per subparts A through G above. 3.6 TOLERANCES A. Top Surface of Backfilling: For under paved areas, plus or minus one-half (1/2) inch from required elevation for aggregate base. B. Top Surface of General Backfilling: Plus or minus one (1) inch from required elevations. DGS Phase 1.1 TR.ENCHING

6 3.7 FIELD QUALITY CONTROL A. Compaction testing and analysis of fill material will be performed in accordance with ANSIIASTM D-698. I. Compaction Requirements: a. Comkact soil more than one (1) foot above pipe for fill width to at least 95% of the laboratory maximum dry density as determined by the Standard Proctor method (ASTM D 698). b. In-place density Will be determined, according to AASHTO or AASHTO T 310. c. The placement moisture content of all fill should be within plus or minus 2 percentage points of the optimum moisture content as determined by ASTM D 698. B: Visual inspection of non-movement &ider compaction equipn{ent may besed where material is' too coalse for testing. C. If tests indicate Work does not meet specified requirements, remove Work, replace and retest at no cost to the Using Agency. D. Frequency of Tests: Maximum, of Eyeiy eight (8) Inches END OF SECTION DOS Phase 1.1 TRENCHING