Extraco has established one central PMV workshop located in the Al–Shahaniyah Area The following describes the proper work procedure that would be carried out during the excavation stage, as per the required specification and contract drawings.

Work Procedure
  • 01.

    Site Preparation

    • Existing Services – The EXTRACO team would conduct an investigation and acquire information about the site services which might have been placed/embedded below the ground. Services, wherever found, shall be rerouted and protected to avoid any disturbance to site activities.
    • Setting out – An EXTRACO surveyor would conduct the site survey to mark/stake-out the lines and levels of the objective excavation for foundations, as indicated in the approved drawings.
  • 02.


    • The area allocated for excavation shall be properly marked and cleared before starting the works.
    • The depth of the excavation shall be periodically checked by a surveyor to avoid over excavation. The bank of the excavated area is sloped at 30 degrees and maintained to avoid a collapse of the bank into the excavated area.
    • All excavated material shall be kept at a minimum of 1.0 meter from the edge of the excavation site or stockpiled in an area designated by the Engineer.
    • Adequate safety barriers, sign boards and advance warning signs are used for all excavation activities.
    • For the foundation, as soon as the excavation reaches the required depth/elevation the surface shall be levelled and compacted to 95 % of the maximum dry density or MDD.
    • Before the compaction starts, the excavated level shall be inspected to insure that it is free from standing water or excessive moisture content.
    • An inspection would be conducted during compaction with the results provided for the review and approval of the Engineer.
    • The compaction test report shall then be submitted to the Engineer for approval prior to proceeding with any subsequent work.
    • Anti-termite treatment would be conducted prior to the start of the blinding works with the anti-termite material inspected/approved by the Engineer.
  • 03.

    Backfilling work

    • After the completion of the compaction under blinding, tie beams and the ground slab, the backfilling shall commence using similar excavated material with care taken to remove any and all boulders, vegetation and other deleterious materials.
    • Prior to backfilling, the compacted surface shall be approved by the Engineer before further work can commence.
    • The thickness of the backfill shall not exceed 300mm.
    • The approved sub-grade, excavated materials, or any other material source approved by the Engineer, shall be placed in layers a maximum of 300 mm thick with a compaction test conducted once the surface level is ready.
    • An in-situ dry density test (compaction test) shall be performed at the rate indicated in the specification.
    • Backfilling, followed by compaction, will continue until the final level is achieved.

Safety Procedures

  • All of our work complies with the safety procedures / instructions set out in the project Safety Plan as well as the Municipality Rules and Regulations
  • Basic Personal Protective Equipment (PPE) is worn by all our staff and labourers
  • A trained operator or banks man is always engaged to control or operate heavy equipment machines

Quality Control

To insure the quality and safety of the work conducted, the following procedures are strictly carried out and monitored throughout our work sites:

  • Directing Cone Penetration Testing (CPT) operation and interpreting results
  • Directing Standard Penetration Test (SPT) operation, classifying soils and interpreting results
  • Soil compaction testing
    • Testing of Backfill for Trenches and Retaining Walls
    • Stabilized base and subbase materials inspection
    • Slurry Wall Construction Oversight and Testing
    • Rigid and flexible pavement construction testing
    • Soil, Rock, and Aggregate Sampling
    • Permeability Testing
    • Concrete Slump Tests and Air Entrainment Determination
    • Rockbolt, Tieback, and Soil Nail Testing
    • Deep and shallow foundation excavation inspection
    • Pile driving inspection, deep soil densification inspection

Our Methodology

  • All personnel entering the site shall have received a site safety induction and have attended a job toolbox talk
  • Before any excavations shall commence, a permit to excavate shall be issued by the site engineer and all persons involved in the task shall be fully briefed
  • All setting out works required, including level profiles and batter rails, shall be set out by the site engineer prior to the commencement of any work
    • Excavation shall be carried out in accordance to the lines and levels shown on the Design Drawings. Excavation shall be carried out by an excavator with material hauled to a fill area by dump trucks
    • When the formation is reached the Contractor shall inform the EXTRACO Site Representative (ESR) accordingly and the area shall be jointly inspected by a Contractor and the ESR Once the area has been deemed acceptable a sign off sheet shall be completed
    • Should any soft spots be encountered below formation level, the area shall be excavated, recorded jointly by the Contractor and the ESR and replaced with acceptable fill material
    • All fill material (including capping) being used in permanent works shall be classified in accordance with the NRA Specification for Road works
    • All formation levels shall be recorded by a site engineer
    • All works will be executed within the permanent fencing boundary
    • Material testing to demonstrate compliance with NRA Specification for roadwork’s and specific contract requirements shall be undertaken