06 Bijzondere werkzaamheden
 >  Working safely in and near wells or trenches
Discussion > Discuss this with your colleagues!

Discuss the following topics with each other:

  • What are the risks associated with activities in and near wells or trenches? How can you mitigate these risks?
Introduction

Each year there are regular occurrences of incidents with respect to activities in and near wells or trenches. This is why we devote attention to working safely in and near wells or trenches in this toolbox.

Risks > What can happen?

Collapse of sloping banks:

  • Due to slopes that are too steep
  • Due to the presence of too much earth/materials/material immediately adjacent to a well or trench
  • Due to vibration caused by, for example, passing vehicles

Falling into a well or trench.

Driving into a well or trench.

Intoxication/suffocation caused by gases escaping from pipelines/contaminated soil.

bicycle path - driving lane cordoned off
earth stored far enough from trench
trench formwork with two escape routes
Measures > What you must do
  • If the depth of a well or trench is more than 1 m the sides must be sloped or formwork must be used.
  • Make the trench wide enough (Table 2).
  • Keep a strip at least 50 cm wide along the well or trench clear from stored earth and/or materials.
  • Vehicles must stay at a distance of at least 0.5 m from the slope. If the well or trench is deeper than 1 m, then this distance must be at least 1 m.
  • Check the slope or formwork daily. After heavy rainfall, additional inspections must be carried out.
  • Remove the paving around the well or trench an additional 0.5 m.
  • Provide due consideration to groundwater and rainwater. If necessary, drain source.
  • Use guide markers, for example, to cordon off the area to prevent vehicles from driving into the well or trench.
  • Ensure there are at least two escape routes in the well or trench, for example ladders or a staircase dug into the slope.
  • Measure the oxygen/gas concentrations at the bottom of the well or trench.
  • In case of any questions about flora and fauna (animals and nature) contact an ecologist: ecologie@heijmans.nl
  • While excavating wells and trenches, the measures specified in the Safely excavating toolbox must be applied.
Table 1: Soil type, depth and slope
Table 2: Minimum trench width
Tips > For more information

Voor meer informatie raadpleeg: "Werken met stabiele grond” / CROW 335. 

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