The following checklist should be used as a guide for better quality control over earth excavation.
(1) Prior to the start of excavation operations, take photographs of the construction area, make sure that sufficient cross—sections are taken, and continue to take progress photographs during construction.
(2) Review the log of borings to ascertain the elevation of the water table and to determine if unsuitable soils are likely to be encountered. Dewatering equipment may be necessary, and disposal for unsuitable material must be provided.
(3) Check Post utility maps prior to the start of excavation to ascertain existing lines not shown on contract drawings.
(4) Evaluate materials being excavated against logs of borings. If differences are noted, consult your supervisor for determination of action to be taken.
(5) Check that approved disposal areas and haul roads are used.
(6) Check for location of required protection to sanitary and storm drains, electrical cables, communications cables and gas lines subject to damage by heavy earth-moving equipment.
(7) Insure the utilization of satisfactory materials from excavations.
(8) Determine moisture condition of suitable excavated materials in advance of needs.
(9) Insist that excavation is performed in specified sequence.
(10) Assure that drainage is provided continually as excavation progresses.
(a) Do not permit ponded water in any construction area.
(b) Be sure that drainage ditches are maintained free flowing.
(11) Insure that required tests for soil bearing characteristics are made upon completion of excavation.
(12) Coordinate planning of borrow excavation to insure that the right materials will be available as needed for embankment construction, and that borrow will not be unnecessarily used when excavated material is available.
(13) Inspect borrow pits for:
Orderly removal of materials.
(14) After total material removal, check borrow pit areas for conformance with final shaping and drainage requirements.
(15) Determine average volume hauled for each type of hauling equipment. Record daily load count for various classifications of excavation when required for partial payments.
(16) Take final cross-sections.
(17) Provide that quantity surveys are made for payment purposes.
(18) Examine all excavating equipment for compliance with General Safety Requirements.
In case of building works following checks should be made during excavation process
(1) Check for contractor’s location, identification and necessary protection for site utilities before operations begin.
(2) Excavated material intended for use as fill must be free of limbs, stumps, roots, brush, vegetation and debris from building foundations, pavements, utilities, etc.
(3) See that the foundation bearing materials agree with the borings.
(4) Check for the proper fill of all depressed areas or holes. (Fill is not permitted beneath footing to correct over excavation.)
(5) Inspect sides of excavations for safe slope (angle of repose) or if sides are made vertical, check adequacy of required bracing to safely retain the sides.
(6) Define provisions made for preventing damage to adjoining property.
(7) Observe method of dewatering excavations and water disposal.
(8) Insure that footing beds in dewatered areas are not disturbed or softened.
(9) See that proper sequence of excavation is carried out for components of the building at different elevations.
(10) Inspect footing and foundation excavations for clearances sufficient to permit erection of forms, installation of services and inspection.
(11) Identify corrective methods used in cases of over excavation.
Do not modify or change established elevations without written approval of the Contracting Officer.
Correct over-excavation by placing approved, compacted backfill or concrete fill, depending on location.
Keep a detailed record of any such corrective work.
(12) Check provisions for preventing surface drainage into the excavated area.
(13) See that footing drains are installed where required.
(14) Determine special instructions and/or requirements when excavations require use of caissons and cofferdams.
(15) Check safety requirements for heavy equipment operating close to deep excavations.