What are geohazards?
Geohazards are ground-related features that can threaten public safety or can have a large impact on the costs and programme of building and infrastructure developments.
Some geohazards are naturally occurring, and others man-made.
The commonest include:
- chemical contamination
- loose and compressible soils
- undermining and natural caverns
- landslides
- buried obstructions
- groundwater
- seismicity
In the development of building and infrastructure projects, geohazards discovered at a late stage are a major cause of cost over-runs and programme delays. They have the potential to overwhelm contingency cost allowances and eliminate development profits.
Mitigation of geohazard risks
Possible mitigation measures for geohazards fall into a number of categories:
- Avoid (plan development so that the hazard has no effect)
- Eliminate (remove the hazard completely)
- Accommodate (design so that the effect of the hazard is acceptable)
- Minimise (treat the hazard so that the effect is reduced to an acceptable level).
Management of geohazards
Halcrow’s objective is to ensure that clients’ business decisions are informed by knowledge of the impact of geohazards and the feasibility of mitigation options.
Effective management of geohazards requires an understanding of the available options, and the associated costs and residual risks.
In the planning of infrastructure projects, early identification of geohazards means that future risks can be effectively mitigated, often without additional cost, and is therefore vital to the planning and financing of successful developments.
To achieve this, Halcrow aims to work with clients through the vital early stages of the development planning process, to ensure that potential geohazards are identified and mitigation actions are planned in advance.