📋 Case Study

Urban Tunnel Construction Vibration & Settlement Risk Model

Ground vibration threatening 19th-century masonry structures within 12m of tunnel alignment

🏗️ Project Overview

Metro extension beneath historic district, Lisbon

🎯 Challenge

Ground vibration threatening 19th-century masonry structures within 12m of tunnel alignment

🔧 Design Approach

Coupled FEM modeling (MIDAS GTS NX) + empirical vibration prediction (Dowding) + real-time piezometer network

📐 Design Diagram

AI-generated project design illustration

📐 Key Calculations

Peak Particle Velocity (PPV)

PPV = K × (D/R)^n

Result: 4.2 mm/s

Below UNESCO limit of 5 mm/s for historic masonry

Settlement Prediction Confidence Interval

σ = ±1.96 × SE

Result: ±1.8 mm

Within allowable 5 mm tolerance per EN 1997-1

📊 Results

Zero structural damage to heritage buildings; 100% compliance with municipal vibration ordinances; project completed 3 weeks ahead of schedule

💡 Lessons Learned

• •Empirical models require site-specific calibration before use
• •Real-time feedback loops enable predictive mitigation adjustments

✅ Key Takeaways

• 1Empirical models require site-specific calibration before use
• 2Real-time feedback loops enable predictive mitigation adjustments