The Invisible Frontline: Why Geohazards and geo-constraints dictate construction success

In the world of engineering construction, what we don’t see is often more critical than what we do. As we push the boundaries of urban expansion both onshore and offshore and face an increasingly volatile climate in 2026 and beyond, the intersection of geohazards and geo-engineering constraints has become the frontline of resilient design.

Building a skyscraper, offshore wind farm or a high-speed rail link isn't just about structural integrity; it’s a negotiation with the Earth (the ground) itself.

Figure 1: Textbook Slickenside found in Colluvium at a site in northern Türkiye ©Precedentconsultants

Defining the Challenge: Hazards vs. Constraints

While often used interchangeably, the industry has shifted toward a more nuanced distinction. According to the framework established by Dimmock et al. (2023) and recently highlighted by Gareth Wood (2026), we must categorize ground risks into two distinct buckets:

• Geohazards (The Dynamic): These are active geo-events or processes that pose an evolving risk to development. They are unpredictable, time-dependent, and managed through rigorous project risk frameworks (e.g., seismic activity, slope instability, or active seabed mobility).

• Geo-engineering Constraints (The Static): These are existing physical features of the ground that pose a challenge to design. They are addressed through routine, albeit complex, engineering solutions (e.g., high plasticity clays, shallow bedrock, or relict glacial features).

The Human Element: When a Process Becomes a Hazard

Building on this, Lee and Griffiths (2024) remind us that a geological process is just "nature" until it meets human ambition. They outline six critical pillars for identifying a geohazard:

1. The Potential for Harm: A geological condition only becomes a "hazard" when it has the potential to impact human activity.

2. The Interface of Encroachment: A landslide in an uninhabited desert is a process; a landslide near a planned rail corridor is a geohazard.

3. Exposure & Vulnerability: Harm is only realized if assets are exposed. If we don’t account for vulnerability, we aren't managing risk—we’re just waiting for it.

4. The Uncertainty of the Future: Geohazards are sources of future risk where the "what" and "when" remain shrouded in uncertainty.

5. Primary vs. Follow-on Impacts: We must account for the "domino effect"—how a primary event (earthquake) triggers a secondary impact (tsunami) and subsequent follow-on failures.

Examples of Geohazards Vs Geo-engineering

The table below provides some examples of Geo-engineering constraints Vs Geohazards Adapted from (Bellwald et al, 2025).

Examples of Geo-engineering constraints	Examples of geohazards
Weathered and unweathered bedrock	Seismicity (earthquakes) / Liquefaction
Gas hydrates / shallow gas	Volcanics (volcanoes)
Faults and fractures	Slope instabilities (Landslides)
Strength variability of geology	Tsunamis
Boulders	Gravity flow dynamics
Chemical composition (aggressivity)	Frost heave / Thaw settlement

Beyond the "Check-the-Box" Mentality

What is clear is that mitigation cannot be a static exercise performed once during the planning phase. It is a continuous loop of monitoring, advanced modelling, and real-time adaptation based on experience and expertise.

The most successful projects this year won't be the ones that "managed to avoid" the ground's constraints. They will be the ones who integrated those constraints into the design's very DNA.

Our Advice: Challenge the Scope

As engineers and consultants, our value lies in our experience. Don’t just accept a client’s initial scope if it underestimates the subsurface reality. Use your expertise to:

• Identify hidden geohazards and geo-constraints early.

• Advocate for the best / higher-resolution site investigations possible to gain the information needed to de-risk.

• Pivot from "defending against nature" to "designing with nature."

  
  

The ground doesn't care about your project timeline. It only cares about physics. Are you listening to what the site is telling you? Time to set a precedent? Please reach out as we have the key expertise in this field. Visit www.precedentconsultants.com to learn more about our services or to schedule a call to discuss your project needs.

Key references

• Dimmock, P.S., Riera, R., Tam, T.A. and Boylan, N. (2023) ‘Geohazard or Geo-Engineering Constraint?’, pp. 2067–2071. doi: 10.3723/LCMM8896.

• EAGE Technical Community on Wind Energy (2026) Geohazards and Geo-engineering Constraints to Wind Farm Development on Formerly Glaciated Margins. Guest speaker: Gareth Wood (bp). [Webinar] 18 February.

• Lee, E.M., Griffiths, J.S., 2024. What is a geohazard? QJEGH 57, qjegh2024-034. https://doi.org/10.1144/qjegh2024-034