The Montana Public Works Standard Specifications are modified as follows:

Transcription

1 The Montana Public Works Standard Specifications are modified as follows: 1. SECTION TRENCH EXCAVATION AND BACKFILL FOR PIPELINES AND APPURTENANT STRUCTURES 02. STANDARD DRAWINGS Standard Drawing No Typical Utility Trench Detail - Delete type 1 pipe bedding and insert pipe bedding material as specified. Standard Drawing No Pipe Bedding Alternate, delete Pipe Bedding shall be a minimum 12 inches above the pipe. 05. B. TRENCH BACKFILL PIPE BEDDING MATERIAL (1) Type 1 Pipe Bedding "PIPE EMBEDMENT. Unless otherwise shown on the drawings, pipe bedding material shall be placed in a thickness equal to ~ x pipe O.D. below the pipe (4 inches minimum) to 6 inches above the pipe. Bedding material shall be clean, non-cohesive, natural, unwashed gravel, sand or crushed hard stone graded as follows: Sieve Size Percent Passing 1" #4 # Less than 10 Except where groundwater is encountered at the trench bottom, in which case embedment material shall be washed, crushed rock passing a I-inch screen. Native trench material shall not be used for pipe bedding material without approval from the City Engineer. In rock areas, the minimum bedding below the pipe shall be 6". Bedding material shall be compacted to 90% of theoretical maxiltium proctor density as determined by AASHTO T -99. Special pipe embedment Inay be required when shown on the drawings. Placement and Compaction. All granular fill material beneath the pipe shall be spread and compacted to provide a uniform and continuous support beneath the pipe at all points between bell holes or pipe joints. It will be permissible to slightly disturb the finished subgrade surface by the withdrawal of pipe slings or other lifting tackle. No part of any bell or coupling shall be in contact with the trench bottom, trench walls, or granular fill when the pipe is jointed. 1

2 After each pipe has been graded, aligned and placed in final position on the bedding materials, and shoved home, sufficient pipe embedment material shall be deposited and compacted under and around each side of the pipe and back of the bell or end thereof to hold the pipe in proper position and alignment during subsequent pipe jointing, embedment and backfilling operations. Embedment material shall be deposited and compacted uniformly and simultaneously on each side of the pipe to prevent lateral displacement of the pipe." C. TRENCH BACKFILL Type A trench backfill will be required in all areas. 2. SECTION 02250, WATERING 03. USE OF CITY WATER: "The Contractor shall be responsible for providing the water required for executing their work." 3. SECTION 02610B, SANITARY SEWER MAIN MATERIALS 03. POL YVINYL CHLORIDE (PVC) PIPE E. Fittings Delete "Wye or" and add the following: "Sewer service connections shall be made by installing either standard tee fittings or tapping saddles. Tapping saddles shall be Predco Fast-Fit sewer saddle with epoxy kit and tapping donut, or equal." 4. SECTION 02722, SANITARY SEWER MAINS STANDARD DRAWINGS "Standard Drawing No Sanitary Sewer and Storm Drain Manhole" - Change channel depth to 0.80 dia. of pipe vice Yz dia. Slope shelf at 1/4" per foot. Delete the following: "Standard Drawing No Standard Cast Iron Cover. "Standard Drawing No Standard 24" Cast Iron Ring No " Manhole Frame "Dept. of Engineering, Missoula, MT - Dwg. STD # 190" PIPE INSTALLATION: E. TOLERANCES "Variance from established line and grade shall not be 2

3 greater than ~ inch, provided that such variation does not result in a level or reverse sloping invert." c.) ) MANHOLES A. GENERAL a. Delete Standard Drawing # and add the following: "Dept. of Engineering, Missoula, MT, STD Dwg. No. 190." b. "Manhole shall have eccentric cones only" 2.) D. RINGS AND COVERS "Dept. of Engineering, Missoula, MT, std. dwg. #190" 3.) F. CONSTRUCTION Paragraph 2, Delete, "The established high groundwater level is as shown on the plans or noted in the Special Provisions." d.) 06. TESTS: 1.) D. T.V. INSPECTION The Engineer shall be required to use a television camera for all sewer inspections before final acceptance. The television inspection shall be done after the seven day deflection test, under the direction of the Engineer and not the Contractor. All lines inspected shall be cleaned with a commercial hydraulic sewer cleaner and televised within one hour of cleaning. An approved measuring device shall also be attached to the camera for verification of ponding. A sewer line is deficient and unacceptable if: (1) The alignment is outside the specified limits, (2) Water ponds in any section equal to or greater than two (2) times the grade tolerance specified under Section , and as modified below, (3) The pipe has visible defects such as open joints, pinched gaskets, cracked barrels or bell, or similar defects. All costs incurred for the television inspection performed shall be the Contractor's responsibility. All television inspections shall be DVD format. Pull the camera through the sewer at thirty (30') feet per minute (9 n1eters per minute maximum). If the camera is pulled by attaching to the hose of a hydraulic sewer cleaner, assure the hose is not active during the pulling process. The Engineer and the City Engineer shall confer and decide as to the remediation if necessary. 3

4 2.) E. DEFLECTION TEST "The 7 day deflection test is required on all City of Missoula sanitary sewer mains." 5. SECTION 2724, SANITARY SEWER AND STORM DRAIN SERVICES 02. STANDARD DRAWINGS: Delete and refer to plans. 03. MATERIALS: "Sewer service connections as shown on the drawings will be marked for location in the field by the Engineer, and shall be made using either standard tee fittings or by installing tapping saddles. Tapping saddles shall be Predco Fast-Fit sewer saddle with epoxy kit and tapping donut, or equal. Flexible couplings shall be flexible elastomeric PVC couplings with stainless steel bands. Flexible couplings shall be designed for connecting gravity sewer pipe and shall be No Series as manufactured by Femco, or an approved equal." c.) 04. INSTALLATION A. GENERAL Delete "standard drawings and " and add the following:... with "Detail on the Plans." E. LAYING PIPE Second paragraph, first and second sentence, delete "wye or" and after "tee fittings... " insert "or tappng saddles." d.) 06. END PIPE MARKER: Change "2" x 2" " to "2" x 4" "and add steel fence post taped to 2 x 4 as shown on plans. 6. ADD SECTION 02725, INSULATION 01. GENERAL This section covers the furnishing and installation of insulation as shown on the drawings and specified. 02. MATERIALS 4

5 Materials shall be as specified herein. Insulation material shall be extruded polystyrene insulation board, in conformance with AASHTO designation M Insulation material shall be designed specifically for inground installation. Installation material shall be square edge and shall have the following properties: A. Compressive Strength: 35 psi minimum at 5 percent deformation of yield, as determined by ASTM D B. Water Absorption (Percent by Volume): 0.25 percent maximum as determined by ASTM C272. C. Thermal Resistance (R) Value: 5.0 ft hr. FIBTU at 75 degrees F, mean temperature in a 1 inch thickness as determined by ASTM C INSTALLATION 7. SECTION 3310, STRUCTURAL CONCRETE Thickness and overall dimensions of insulation material shall be as shown on the drawings. Minimum length of insulation material boards shall be 8 feet. Insulation material shall be installed in the locations shown on the drawings. Each thickness shall be obtained by the use of at least two layers of insulation material boards with staggered joints to prevent heat loss. All joints shall be tightly butted. All field cutting of insulation material board shall be done with a straight edge to a neat line. Insulation shall be covered with 6 inches minimum of pipe bedding material prior to backfilling, except in location of shallow bury (8 inches or less) where the insulation is backfilled with topsoil. 03. COMPOSITION OF CONCRETE C. PROPORTIONING - Table 1 Add to M3000 "Minimum cement content is 5 12 sacks per cubic yard." Add to M4000 "!v:iinimum cement content is 6 Yz sacks per cubic yard." 5