PIPE SUBDRAINS - Item No. VIDEO CAMERA INSPECTION Item No. Special Provision No. 405F03 March 2005 OPSS 405, February 1990, Construction Specification for Pipe Subdrains is deleted in its entirety and replaced with the following: 405.01 SCOPE This special provision covers the requirements for the construction of pipe subdrains. 405.02 REFERENCES This special provision refers to the following standards, specifications and publications: Ontario Provincial Standard Specifications, Construction: OPSS 180 OPSS 421 OPSS 501 Management of Surplus Material Pipe Culverts Compacting Ontario Provincial Standard Specifications, Material: OPSS 1004 OPSS 1010 OPSS 1801 OPSS 1840 OPSS 1841 OPSS 1860 Aggregates Miscellaneous Aggregates Base, Subbase, Select Subgrade and Backfill Material Corrugated Steel Pipe Products Non-pressure Polyethylene Plastic Pipe Products Polyvinyl Chloride Pipe (PVC) Products Geotextiles Canadian Standards Association: CSA G164-M1981 Hot Dip Galvanizing of Irregularly Shaped Articles Canadian General Standards Board: CGSB 41-GP-29Ma-1983 Tubing, Plastic, Corrugated, Drainage 405.03 DEFINITIONS Geotextile-knitted sock: Means a textile structure produced by knitting in a continuous tube specifically intended to cover perforated plastic subdrain pipe and corrugated steel pipe. Knitted geotextiles are suitable only for wrapping of perforated plastic subdrain and corrugated steel pipe unless otherwise specified in the Contract. Outlet: means the terminal 2.5 m of the outlet pipe. March 2005 Page 1 of 5 SSP405F03
Subdrain: means a small diameter pipe, perforated or non-perforated, which is placed for the purpose of collecting sub-surface water and conveying it to a proper outlet. Subdrain may be corrugated steel, polyethylene or polyvinyl pipe product. 405.05 MATERIALS 405.05.01 General The subdrain shall be a perforated corrugated steel pipe, perforated polyvinyl chloride pipe or perforated polyethylene pipe. Previously used pipe shall not be used for the proposed subdrain installation. 405.05.02 Corrugated Steel Pipe Products Corrugated steel pipe products shall be according to OPSS 1801. of the corrugated steel pipe with a geotextile knitted sock, by the manufacturer, is not required. 405.05.03 Polyethylene Pipe Products Polyethylene pipe products shall be according to OPSS 1840 and CGSB 41-GP-29M. of the polyethylene pipe with a geotextile knitted sock, by the manufacturer, is not required. 405.05.04 Polyvinyl Chloride Pipe Products Polyvinyl chloride pipe products shall be according to OPSS 1841. of the polyvinyl chloride pipe with a geotextile knitted sock, by the manufacturer, is not required. 405.05.05 Geotextile Geotextiles shall be according to OPSS 1860. 405.05.06 Fittings Fittings shall be suitable for and compatible with the class and type of pipe with which they will be used. Plugs where used shall be polyethylene. Galvanizing of rodent gates shall be according to CSA G164. 405.05.07 Outlets The outlets shall be constructed of non-perforated corrugated steel pipe or double walled polyethylene or polyvinyl chloride pipe having a minimum stiffness of 300 kpa. A material specification from the manufacturer shall be submitted upon request by the Contract Administrator to verify the material supplied meets Contract requirements. March 2005 Page 2 of 5 SSP405F03
405.05.08 Granular Backfill and Bedding Granular material for backfill and bedding shall be according to OPSS 1010. Clear stone shall be according to OPSS 1004. 405.07 CONSTRUCTION 405.07.01 Roadway Installations by Trenching 405.07.01.01 Excavations Trenches shall be excavated to the width, grade and alignment specified in the Contract Documents. The stability of the trench shall be maintained at all times during excavation and backfilling. The excavation shall be inspected with grade checks and certified by the Contractor prior to placement of the pipe bedding. An inspection report shall be submitted to the Contract Administrator upon request. 405.07.01.02 Pipe Bedding Trenches shall be excavated a minimum of 50 mm below the pipe bottom. The additional depth below the bottom of the pipe shall be backfilled with pipe bedding consisting of granular material conforming to the contract requirements. The pipe bedding shall be inspected with grade checks and certified by the Contractor prior to laying the pipe. An inspection report shall be submitted to the Contract Administrator upon request. 405.07.01.03 Unstable Foundations The Contractor shall take the necessary steps to ensure a stable foundation when unstable foundations conditions are encountered. An inspection report to verify the foundations stability shall be submitted to the Contract Administrator upon request. 405.07.02 Laying Pipe 405.07.02.01 General The Contractor shall replace any pipe or geotextile damaged by exposure to sunlight or damaged by any other means. Where a geotextile wrapped trench is required, the geotextile shall be placed prior to placement of the bedding and backfill material. Where granular backfill is specified, the geotextile shall be installed as detailed elsewhere in the Contract Documents with the ends overlapped 300 mm minimum. Pipe installation shall be according to OPSS 421. The pipe shall be placed firmly on the bedding and secured in place to prevent any movement or disturbance during backfilling. Pipe with one side perforation shall be installed with perforations down. Pipe shall not be laid in water or on wet bedding. The pipe shall not be used as a drain for the Contractor s operation. Connections to outlet pipes shall be made with prefabricated 45 elbows or pre-manufactured pipe curves as required. March 2005 Page 3 of 5 SSP405F03
The pipe installation shall be inspected and approved by the Contractor prior to backfilling. An inspection report shall be submitted to the Contract Administrator upon request. 405.07.03 Installation of Subdrain Outlets 405.07.03.01 General Outlets shall be installed at all low lying areas, at the end of subdrain pipes, and at a uniform spacing of 100 m along the length of the subdrain pipe. The ends of all outlets shall be fitted with galvanized rodent gates. Outlets shall be of similar inside diameter as the outlet pipe, yet large enough so the outlet pipe can be inserted into the outlet. Outlets shall extend beyond the front of the ditch or fill slope for a distance of 300 mm. The outlet pipes shall be inserted a minimum distance of 300 mm into the outlet. The joint between the outlet and the outlet pipe shall be wrapped with a 0.5 m width of geotextile. 405.07.03.02 Marking of Outlets The Contractor shall mark each outlet location with 25 x 25 mm square galvanized steel bar, 2.2 m long embedded a minimum of 0.6 m and a maximum of 1.0 m into the ground, adjacent to the outlet clearly visible from the driving portion of the roadway. 405.07.04 Connection to Drainage Structures Subdrain connections to concrete manholes, catch basins and ditch inlets shall be grouted. Subdrain connections to corrugated steel pipe manholes, catchbasins and ditch inlets shall include a 1.0 m corrugated steel pipe section which shall be welded to the corrugated steel pipe manhole, catchbasin or ditch inlet. 405.07.05 Backfilling Backfill for all subdrain and outlet pipes shall consist of 19 mm clear stone or granular material as specified in the Contract Documents. Any earth from cave-ins, and all other unsuitable material shall be removed. Cracked or crushed pipes shall be removed and replaced before any backfilling is commenced. At the termination of a day s work, backfilling shall be complete to the end of the subdrain pipe and outlet pipe. Where 19 mm clear stone is specified, the subdrain trench and the outlet trench shall be wrapped with a nonwoven geotextile as specified in the Contract Document. The Contractor shall ensure that the subdrain pipe and outlet pipe is not damaged or dislodged during the placement and compaction of the backfill. Compaction of backfill material shall be according to OPSS 501. March 2005 Page 4 of 5 SSP405F03
405.07.05.01 Winter Grading of Material All ice and snow shall be removed from all portions of the work area. Frozen materials shall not be incorporated into the work. Material shall not be placed over frozen ground, ice or snow, except, at the Contractor's option, a single lift may be placed over frozen ground in which case final grading and compaction shall be done after the underlying materials have thawed. 405.07.06 Management of Surplus Material Management of all surplus material shall be according to OPSS 180 unless specified elsewhere in the Contract Documents. * Designer fill-in, see Notes to Designer 405.09 MEASUREMENT FOR PAYMENT 405.09.01 Pipe Subdrain Measurement is by Plan Quantity as may be revised by Adjusted Plan Quantity in metres horizontally over the centreline of the pipe between the ends of the pipe subdrain including outlets where applicable or between the upstream end and the centre of the manholes, catchbasin or inlets. ** Designer fill-in, see Notes to Designer 405.10 BASIS OF PAYMENT 405.10.01 Pipe Subdrain Item Payment at the contract price for the above tender item shall be full compensation for all labour, equipment and materials to do the work. Where excavation and backfilling of subdrains overlaps excavation and backfilling required for other work, then payment for overlapping excavation and backfilling will be made in accordance with the specifications for such other work as though no excavation and backfilling were required for pipe subdrains. Where the subdrain is below subgrade, and the subdrain backfill placed below the subgrade is the same material that is used in the roadbed, the granular backfill shall be paid for with the granular item for the roadbed. Where the subdrain granular backfill placed below the subgrade is material other than the one used for the roadbed, payment for the backfill shall be included in the contract price for the pipe subdrain. *** Designer fill-in, see Notes to Designer March 2005 Page 5 of 5 SSP405F03