PROJECT SNAPSHOT

• Location: Europe (confidential project).
• Soil conditions: layered soils (sand, silt, cohesive layers).
• Pile type: bored piles.
• Pile depth: ~15–24 m.
• Role: Independent expert analysis and validation.

THE PROBLEM

Pile capacity was estimated using PressureMeter Testing (PMT) in complex layered soils. However, key uncertainties remained:

• actual shaft resistance mobilization,
• reliability of deformation parameters,
• real load–settlement behavior.

→ Design values required verification under real loading conditions.

OUR APPROACH

We performed a combined analysis using:

• Dynamic Load Testing (DLT) → real pile response,
• PressureMeter Testing (PMT) → soil parameters for design.

→ Advanced signal matching was used to interpret DLT results and derive realistic static behavior.

KEY RESULT

DLT confirmed higher pile capacity compared to PMT-based design values.

• Higher mobilized shaft resistance observed.
• Improved load–settlement performance confirmed.
• PMT-based design proved conservative in layered soils.
• DLT indicated up to 20–30% higher capacity compared to PMT-based design values.

→ DLT showed consistently higher pile capacity compared to PMT-based design values.

ENGINEERING INSIGHT

• DLT reflects actual pile–soil interaction.
• PMT provides reliable but design-oriented estimates.
• Differences result from soil layering effects and limitations of analytical models.

→ Both methods are complementary — not contradictory.

Comparison of mobilized (DLT) and design (PMT) pile capacities for tested piles.
DLT results consistently exceed PMT-based design values, indicating conservative analytical estimates.

BUSINESS IMPACT

• Reduced uncertainty in foundation design.
• Increased reliability of pile capacity assessment.
• Identification of conservative design assumptions.

→ Supports cost optimization and risk-informed decision-making.

CONCLUSION

The combined DLT + PMT approach provides:

• validated pile performance,
• improved confidence in design,
• a more reliable foundation solution.

Cosic M., Susic N.: Comparative Analysis of Bearing Capacity of Piles Tested by Dynamic Load Test (DLT) and Pressuremeter Test (PMT), 5^th symposium of the Macedonian Association for Geotechnics, Ohrid, Macedonia, 2022, pp. 344-354.