Table of Contents

    Methodology for Pipe Culverts

    1. Scope

    The work shall consist of furnishing and installing the required length, type, and size of reinforced cement concrete pipes at locations shown in the drawings or as directed by the Contract Agreement (CA).

    2. Reference

    • Contract Agreement
    • IRC: SP: 84-2014
    • MoRTH Specifications (5th Revision)
    • Relevant Approved Drawings

    3. Setting Out

    After completion of site clearance, alignment of the culvert shall be surveyed and marked on the ground using lime and string for locating the culvert and associated structures.

    Temporary Bench Marks (TBM) shall be established near the structure location for construction reference. TBM locations shall be selected carefully to avoid disturbance during construction activities and shall remain intact until completion of the work.

    4. Working Drawings

    Working drawings, structural drawings, and relevant details shall be submitted to the AE before commencement of work. After review and approval by the AE, setting out of the structures shall be carried out.

    🚀 QA/QC Toolkit ₹299
    Buy Now

    5. Selection of Materials

    All materials used in pipe culvert construction shall conform to Section 2900 of MoRTH Specifications.

    • RCC pipes shall be inspected and approved by the AE before use.
    • Manufacturing test certificates shall be submitted for approval.
    • PCC, RCC, aggregates, and jointing materials shall conform to approved specifications.

    6. Equipment & Machinery

    • Hydraulic Excavator
    • Hydraulic Crane / Hydra
    • Dumper
    • Plate Compactor
    • Mechanical / Pneumatic Tampers
    • Water Tanker
    • Tractor Trolley

    7. Method of Operation

    1. Foundation bed for pipe culverts shall be excavated true to the lines and grades shown in approved drawings or as directed by the AE.
    2. Pipes shall be laid either in shallow excavation of natural ground or in trenches cut through existing embankment to required levels.
    3. Where trench excavation is required, trench width shall be maintained at a minimum of 150 mm or one-fourth of pipe diameter on either side, whichever is greater, but not exceeding one-third of pipe diameter.
    4. Sides of trenches shall be kept as vertical as possible and pipes shall be laid on PCC bedding.
    5. The bedding surface shall provide a firm and uniform foundation throughout the culvert length at required line, level, and grade.
    6. After completion of bedding, pipes shall be carefully laid to the required line and level without damage and as approved by the AE.
    7. Where multiple pipes are laid, minimum clear spacing between pipes shall be half the pipe diameter or minimum 500 mm.
    8. Pipe laying shall commence from the outlet side (downstream) towards the inlet side (upstream) to ensure smooth invert alignment.
    9. In bell-mouth pipes, the belled end shall face upstream direction.
    10. Pipe joints shall be made as per approved drawings and specifications.
    11. For light hydraulic pressure joints, recesses at pipe ends shall be filled with jute braiding dipped in hot bitumen or approved compound.
    12. Bitumen rings shall be properly compressed by jacking or suitable approved methods to ensure watertight joints.
    13. All joints shall be finished flush with the internal pipe surface and kept damp for at least four days after completion.
    14. Backfilling shall commence only after jointing materials have adequately hardened.
    15. Backfill material shall be clean and free from boulders, roots, organic matter, and oversized lumps.
    16. Backfilling shall be carried out equally on both sides of the pipe to avoid unequal pressure.
    17. Backfill shall be placed in layers not exceeding 150 mm thickness and compacted thoroughly using approved compaction equipment.
    18. Special attention shall be given to compaction around the haunch portion of the pipe.
    19. Head walls, wing walls, aprons, and ancillary works shall be constructed as per approved drawings and relevant MoRTH sections.
    20. RCC works shall conform to Sections 1500, 1700, 2100, 2200, or 2300 as applicable.
    21. Apron and protection works shall conform to Section 2500 of MoRTH Specifications.

    8. Opening to Traffic

    Traffic shall be allowed over the pipe culvert only after providing a minimum earth cushion of 600 mm above the top of the pipe or as specified in approved drawings.

    🚀 QA/QC Toolkit ₹299
    Buy Now

    9. Quality Control

    • Checking of Line, Level & Alignment
    • Inspection of Bedding & PCC
    • Pipe Joint Inspection
    • Compaction Testing of Backfill
    • Material Testing as per MoRTH Specifications
    • Inspection of Headwall & Protection Works

    10. Safety

    1. All machinery and lifting equipment shall be inspected before use.
    2. Barricading and caution boards shall be provided around excavation areas.
    3. Workers shall wear PPE such as helmets, safety shoes, reflective jackets, gloves, and masks.
    4. Proper traffic diversion and warning signs shall be maintained throughout the construction period.
    5. Safe lifting practices shall be followed during pipe handling and placement.