Alert of the Month

Incident Details

Heavy precipitation and snowmelt on an old, unmaintained logging road 600 metres above the work zone initiated a landslide. The landslide swept down the mountainside through an active cutblock, carrying a loaded logging truck and its driver downslope approximately 300 metres, burying the truck in debris.

Learnings & Suggestions

• Logging plans for a cutblock should include an assessment of potential upslope hazards, such as abandoned or non-deactivated roads, and how they might impact slope stability during prolonged rain or snowfall.
• If upslope roads are not deactivated or maintained and are creating a landslide risk, contact relevant authorities to develop a mitigation plan.
• Be certain that all workers, supervisors and managers understand the implications of the increased risk of landslide caused by the amount of soil saturation from not just rainfall, but also melting snow. Snowmelt should be considered as additional precipitation, beyond any precipitation already measured.
• Make sure field staff are trained in rainfall monitoring/shutdown procedures which include collecting rain and snow accumulation data, interpretation of the data and making informed decisions to shut down or keep working.
• New road construction operations on moderate to steep slopes can also create a risk of causing landslides. Site indicators to be aware of include wet organic soils particularly when over smooth bedrock and pistol butt or jack-strawed trees.

Jack-strawed trees

Resources

1. WorkSafeBC’s Incident Investigation Report Summary for this incident
   http://www.worksafebc.com/en/resources/health-safety/incident-investigation-report-summaries/logging-truck-swept-off-road-by-landslide?lang=en
2. Road Construction Initiated Slides Awareness Videos and Training
   http://www.bcforestsafe.org/CISWG

Example of landslide caused during road construction.