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General Civil Engineering

Designers Knowledge Base

Including small works.


When designing general civil engineering works the designer should be aware of the following principal hazards which could be encountered.

Possible principal hazards and risks

  • health hazards caused by contaminated ground, manual handling, gases, water borne diseases and contamination and the possibility of exposure to asbestos
  • falls caused by unsafe access or egress and unsafe working platforms
  • hazards of contact with overhead and buried services such as electricity, fuel and gas pipelines, sewers or high pressure mains water
  • hazards associated with vehicles and plant on the site
  • hazards associated with the collapse of excavations caused by inadequate support or the collapse of falsework/formwork
  • the hazards posed by incidents such as landslip, flooding or subsidence


The designer should obtain a full history of the site which may indicate previous contamination. A ground survey should indicate any foundation problems. Is there any likelihood of flooding, where are the services and should they be diverted or protected, will there be enough working room for the items of plant to be used?

Possible design options to avoid hazards

  • design to consider the effect on the local environment of egress and access to the site and noise, vibration, lighting etc
  • avoid disturbance of existing services
  • consider a massing arrangement of structures which will allow excavations with wide batter
  • consider alternative layouts or routes which may be less hazardous
  • attempt to improve the stability of excavations by designing drainage measures
  • consider working space available when considering construction methods
  • minimise excavation depths
  • protect or divert existing services by the use of an enabling works contract
  • design systems for future safe maintenance, cleaning and eventual demolition