Method Statement For Backfilling Behind Abutment & Around Structures.

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This Method Statement provides detail of procedure adopted for the construction of backfilling behind structures and abutment.

  • Scope

This work will consist of backfilling behind abutment of bridges and around structures like foundations, underpass, box culvert and other similar structures in accordance with the requirements of these specifications (MoRT&H clause no. 305.4.4) and lines & dimensions shown in the drawing or as indicated by the Engineer.

  • Material

Approved material will be used as a backfill material from approved sources. Fill material shall be free from logs, stumps, roots, rubbish or any other ingredients likely to deteriorate or affect the structure.

  • Responsibility

Section In charge will be responsible for quality control of the section for the backfilling work. He will liaise with Concessionaire Engineer In Charge. Further he will be assisted by field Engineers, Surveyors, Supervisors and lab technicians.

  • Equipment

The following construction machineries will be deployed for backfilling work.

Dumper / trucks


Small Vibratory Roller

Water tanker

Plate Compactor

  • Procedure
    • Backfilling around structures

Backfilling will be done with approved material after concrete or masonry is fully set and carried out in such a way as not to cause undue thrust on any part of the structure. All spaces between foundation, masonry or concrete and sites of excavation will be backfilled. Fill material will be spread in layers manually or by grader in layers of uniform thickness not exceeding 250mm compacted thickness over the entire width of the structure. Each layer of approved materials will be thoroughly compacted after necessary watering by means of small vibratory rollers/plate compactor or thoroughly rammed in small areas where mechanical means cannot be deployed. Successive layers will not be placed until the layers under construction have been thoroughly compacted to the specified requirement of table 300-2, i: e; 95% and 97% of MDD at OMC for embankment and sub grade respectively.

  • Backfilling Behind abutment and Wing wall

Filling behind abutments and wing walls for all structures without weep-hole, will be done with approved filling material. The fill material will be deposited in loose thickness and compacted after necessary watering up to a thickness of 250mm, until the required compaction of 95% & 97% of MDD at OMC achieved, for embankment & sub grade respectively. Filling will be carried out in equal layers on each side of the structures to avoid displacement and unequal pressure.

Where provision of any filter media is specified behind abutment (where weep-hole exists), filter media as designed will be laid and compacted after necessary watering up to a compacted thickness of 250mm until 95% & 97% of MDD at OMC achieved, for embankment & sub grade respectively. The material used for filter media will conform to the requirement for filter medium spelt out in clause 2504.2 / 309.3.2.

If impracticable to use conventional rollers, the compaction will be carried out by mechanical means like small vibratory roller/plate compactor. Care will be taken to see that, the compaction Equipment does not hit or come too close to any structural member, so as to cause any damage to them or excessive pressure against the structure.

  • Quality Control and Testing

Quality control tests shall be done as per Sl. no. 1 of Quality Control Tests and Acceptance Criteria

  • Safety & Environment

While working Safety & Environment Procedure shall be followed as per approved EHS Manual.


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