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Investigation of the Site

Designers Knowledge Base

Includes surveys of structures, materials, building services, topography and ground movement. Also includes trial pits, rock coring, ground and soil sampling and in-situ field testing.


In investigating the site the designer should be aware of, and assess the risks from, the following principal hazards.

Some principal hazards and risks

  • hazards to health caused by noxious or toxic fumes and hazardous materials and substances
  • confined spaces in structures, service ducts, sewers and manholes
  • collapse of structures and excavations
  • falling from height from structures, into voids and from edges
  • hazards from existing services such as electric cables both below ground and above ground level
  • hazards caused by slope instability, underground voids or the inability to support loads or weights


Consideration should be given to the age and condition of any buildings or structures. Routes and safe access to investigation zones. Consider the treatment of any contamination and the stability of the site or working platform. Where have existing services been located, disconnected or exposed and is it necessary to use any heavy equipment?

Possible design options

  • consider whether existing available information about the site is accurate and adequate. Will it be necessary to have an independent survey or investigation?
  • review the necessity of a pre-investigation survey or cleansing operation to protect the investigation team or provide more information
  • ensure any risks from electricity are highlighted
  • distribute boreholes with respect to accessibility and buried obstructions
  • where necessary ensure investigation team is competent and protected