Backfilling :
1. Suitable fill materials shall mean materials excavated from the site, or imported from outside that are in conformance with the specifications and are approved by the Principal for their intended use. Suitable fill materials shall be free from refuse, large stones or rocks, or other material which might prevent proper compaction or cause the compacted fill or embankment to perform inadequately, or to have insufficient stability or bearing capacity for the superimposed loads to which it is likely to be subjected. The criteria for the various types of suitable fill materials are provided in the following sections.
2. Soil and rock classification shall be carried out in accordance with BS 1377, ASTM D 2487, ASTM D 2488 or other standard approved by the Principal.
3. Sampling and testing of material at source shall not preclude future rejection if it is subsequently determined to lack uniformity or it fails to conform to specified requirements, or otherwise judged unsuitable by the Geotechnical Engineer or the Principal.
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