All subsoils have different abilities in remaining stable during
excavation works. Most will assume a natural angle of repose or
rest unless given temporary support. The presence of ground
water apart from creating difficult working conditions can have an
adverse effect on the subsoil's natural angle of repose.
Time factors such as period during which excavation will remain
open and the time of year when work is carried out.
The need for an assessment of risk with regard to the support of
excavations and protection of people within, is contained in the
Construction (Health, Safety and Welfare) Regulations 1996.
Excavations up to 2.5 m deep---Temporary Support