Underground Pipelines Module #8 Prepared by Dr. Randy R. Rapp July 2005
Feb 24, 2016
Underground PipelinesModule #8
Prepared by
Dr. Randy R. RappJuly 2005
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Installation Methods
• Trenching and backfilling (cut and cover)– Traditional– Bedding can be critical
• Pipe jacking• Horizontal directional drilling• Slip lining• Pipe bursting
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Horizontal Directional Drill
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HDD Reception Pit
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Plastic Pipe
• PVC, PE, HDPE• Protect joints
– Solvents, thermal (PE, HDPE), or threads– Snaking– Bedding and backfilling– Flotation– No blocking– Expansion loops or joints– Supports
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Vitreous Clay Pipe (VCP)
• National Clay Pipe Institute standards, p. 183; Table 8-2
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Concrete Pipe
• Unreinforced• RCP, Reinforced Concrete Pipe
– Reinforcement patterns– Inspection and preparation– Laying and jointing– Bedding and backfill
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RCCP (Reinforced Concrete Cylinder Pipe) and ML&C (Mortar-Lined and
Coated Steel Pipe)
• Delivery, storage and handling• Excavation and bedding• Lifting and positioning• Jointing• Backfilling and compaction
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Trenches
• Sheeting• Subsidence• Specifications• Backfilling
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Payment
• Station lengths, if specified• Otherwise, slope length
– Length placed before cutting, rounded up to nearest 2-ft increment
– If centerline is skewed, use longer side– Include any “formed out” distance