Operations on earthwork shall be suspended at any time when satisfactory results cannot be obtained because of rain, or other unsatisfactory field conditions. The Contractor shall drag, blade, or slope the embankment to provide proper surface drainage. 

The material in the layers shall be of the proper moisture content before compaction. Wetting or dry- ing of the material and manipulation when necessary to secure uniform moisture content throughout the layer may be required. 

The Contractor shall take all necessary precautions to protect exposed faces against deterioration. 

The Contractor shall compact the fill using approved compacting methods and equipment. Backfilling shall not impose uneven or excessive load on a structure. 

All material used for filling shall be deposited and compacted as soon as practicable after excavation in layers of thickness appropriate to the compaction plant used. Filling of areas and embankments shall be built up evenly over the full width and shall be maintained at all times with a sufficient camber and a surface sufficiently even to enable surface water to drain readily from them. 

## 5.2.9.3 Trial Area of Filling 

Where required by the Engineer and before commencing filling, the Contractor shall at his own ex- pense compact a trial area of filling of the type proposed using the equipment proposed for the works in accordance with specified standards of compaction. The area shall be of a size and depth to the ap- proval of the Engineer sufficient for the trial to adequately represent the work involved in the general filling operations. 

Variations of method or equipment will only be permitted when the Contractor demonstrates by field trials that the compaction obtained by the alternative method achieves compaction equivalent to that obtained by the approved method. 

During the progress of the works the Contractor shall inform the Engineer of any factors outside his control which may adversely affect the compaction achieve so that the Engineer can give considera- tion to a variation of the equipment or method. 

## 5.2.9.4 Filling Adjacent to Structures 

Filling against the perimeter of structures shall not be carried out until the Engineer agrees that the construction is sufficiently advanced implying no risk of interferences or damage from either the com- paction equipment or the backfilling material. 

Filling material for excavations and for making up levels within the perimeter of structures shall be suitable material and shall contain no particular size in excess of 50 mm. The compaction of fill mate- rial within the perimeter of structures shall be carried out with equipment suited to the area being compacted. 

## 5.2.9.5 Tolerances for Filling 

The fill shall be placed and compacted to a tolerance of –10 mm/+ 15 mm for a final surface. Where further works will be carried out above the fill the tolerance shall be –25 mm/+0 mm. 

Within the above tolerances the surface shall have a smooth regular face all to the approval of the En- gineer. 

## 5.2.9.6 Control and Testing of the Fill 

Control testing shall be carried out by members of the Contractor's staff competent to perform the re- quired tests. Additional testing may be carried out at the discretion of the Engineer. 

Soil compaction tests shall be carried out according to the relevant standards. 

