1 GENERAL

A site investigation is one form or another is always requried for any engineering or bulding structure. The investigation may range in scope from a simple examination of the surface soils with or without a few shallo trial pits, to a detailed study of the soil and ground water conditions to a considerable depth below the sirface by means of boreholes and in-situ and laboratory tests on the materials encountered.

The extent of the work depends o the importance and foundation arrangement of the structure, the complexity of the soil conditions, and the information which may be available on the behaviour of existing foundations on similar soils. Thus it is not the normal practice to sink boreholes and carry out soil tests for single or two storey dwelling houses or similar structures since there is isually adeuqate knowledge of the required foundation depths and bearing pressures in any particular locality. Sufficient information to check the presumed soil conditions can usually be obtained by examining open sewer trenches or shallow excavations for roadworks, or from a few shallow trial pits or hand auger borings.

A detailed site investigation involving deep boreholes and laboratory testing of soils is always a necessity for heavy structures such as bridges, multi-storey buildings or industrial plants.

2 INFORMATION REQUIRED FROM A SITE INVESTIGATION

Assuming a fairly detailed study is required,the following information should be obtained in the course of a site investigation for foundation engineering purposes :

(a) The general topography of the site as it affects foundation design and construction, e.g. surface configuration, adjacent property, the presence of watercourses, ponds, hedges, trees, rock outcrops, etc., and the available access for construction vehecles and plants.

(b) The location of buried services such as electric power and telephone cables, water mains and sewers.

(c) The general geology of the area with particular reference to the main geological formations underlying the site and the possibility of subsidence from mineral extraction or other causes.

(d) The previous history and use of the site including information on any defects or failures of existing or former buildings attributable to foundation conditions.

(e) Any special features such as the possibility of flooding, seasoning swelling and shrinkage, soil erosion etc.

(f) A detailed record of the soil and rock strata and ground conditions within the zones affected by foundation bearing pressures and construction operations.

(g) Results of laboratory tests on soil and rock samples appropriate to the particualr foundation design or constructional problems.

3 SITE WORKS AND SETTING OUT

After a site is handed over, the task of preparing for and setting out of the building can commence. These operation can be grouped under three headings:

(1) Clearing of Site

(2) Setting out the Building

(3) Establishing a Datum Level

Accomodation

- first aid

- washing facilities

- meal room

- sanitary facilities

Storage

- cover / no cover

- durability

- security

Fencing

- security

Hoarding

- safety

Movement

Electricity Supply

- portable self-powered generator

- metered supply from local authority

Water Supply