4.2.2.

(1) A subsurface investigation, including groundwater conditions, shall be carried out, by or under the direction of a person having knowledge and experience in planning and executing such investigations to a degree appropriate for the building and its use, the ground and the surrounding site conditions.

(1) A field review shall be carried out by the designer or by another suitably qualified person to ascertain that the subsurface conditions are consistent with the design and that construction is carried out in accordance with the design and good engineering practice.

(2) The review required in Sentence (1) shall be carried out,

(a) on a continuous basis,

(i) during the construction of all deep foundation units with all pertinent information recorded for each foundation unit,

(ii) during the installation and removal of retaining structures and related backfilling operations, and

(iii) during the placement of engineered fills that are to be used to support the foundation units, and

(b) as required, unless otherwise directed by the chief building official,

(i) in the construction of all shallow foundation units, and

(ii) in excavating, dewatering and other related works.

(1) If during construction, the soil, rock or groundwater is found not to be of the type or in the condition used in design, and as indicated on the drawings, the design shall be reassessed by the designer.

(2) If during construction, climatic or any other conditions have changed the properties of the soil, rock or groundwater, the design shall be reassessed by the designer.