Following the 1998–2000 rehabilitation works designed by Prof. M. P. Petrangeli (Structural Consultant) and coordinated by Dr. Eng. E. Codacci-Pisanelli, LGEngineering Ltd conducted an independent post-rehabilitation verification assessment of the Wadi Kuf Bridge. The rehabilitation addressed critical issues including creep-induced prestress losses, limited torsional stiffness of the deck, damaged central span bearings, and deteriorated stay cable concrete protection. Our assessment comprised a comprehensive structural evaluation of the entire bridge, with particular emphasis on verifying the performance of the newly installed elements:

14 Macallay bars (26.5mm diameter) – integrative prestressing along top slab

20 strand tendons (4 × 0.6" HDPE-coated strands) – integrative prestressing along bottom slabAnti-torsion rings – transverse stiffening within the box girder

New seismic-resistant bearings – replacement of damaged central span supports

Assessment Methodology

All testing was conducted using non-destructive techniques, including:

Vibrating wire strain gauges for bar and tendon stress monitoring

Electronic total stations and inclinometers for torsional deflection measurement

Radar interferometric deformation measurement (IBIS-S) for cable force verification

Dynamic testing for natural frequency extraction

Independent Finite Element Modeling (MIDAS/Civil) for baseline validation

Key Findings

1. Integrative Prestressing (Macallay Bars & Strand Tendons)

Element Design Stress Measured Stress Deviation Status Status

Macallay Bars (14 units) 1,050 MPa 1,033 – 1,061 MPa -1.6% to +1.0% ✅ PASS

Strand Tendons (20 units) 850 kN 842.5 – 857.8 kN -0.9% to +0.9% ✅ PASS

Conclusion: All prestressing elements are performing within design specifications, confirming successful recovery of creep-related losses.

2. Anti-Torsion Rings (Torsional Stiffness)

Parameter Pre-Rehab Post-Rehab (Theoretical) Measured Improvement

Torsional Deflection (Eccentric Load) 8.2 mm 7.0 mm 6.8 – 6.9 mm ~16.5%

Conclusion: The anti-torsion rings have achieved a 16.5% improvement in deck torsional stiffness, exceeding the design target of 10-15%.

3. New Seismic-Resistant Bearings

Parameter Theoretical Measured Deviation Status

Vertical Compression 1.2 mm 1.1 – 1.3 mm ±0.1 mm ✅ PASS

Longitudinal Displacement 3.8 mm3.6 – 3.9 mm ±0.2 mm ✅ PASS

Conclusion: The new bearings are correctly installed and fully operational, confirming successful lifting and repositioning of the central span (maximum lift: 12mm).

4. Structural Performance (Whole Bridge)

Parameter FE Prediction Field Measurement Correlation

1st Vertical Natural Frequency 0.314 Hz 0.318 Hz 98.7%

Midspan Deflection (Symmetric Load) 112.0 mm 108.5 mm 96.9% Maximum Strain (Bottom Slab ) 85.6 µε 82.3 µε 96.1% Cable Force Increment Varies by cable Within ±10% of predicted ✅ PASS

Elastic Rebound ≥ 90% 94.2% ✅ PASS

Conclusion: The bridge as a whole exhibits excellent structural behavior, with all measured responses within the theoretically predicted ranges. The calibration coefficients for displacement and strain are consistently less than 1.0, indicating that the structure possesses adequate stiffness and strength.

5. Stay Cable Concrete Repairs

Visual inspection confirmed:

Demolished and reconstructed concrete surfaces are sound

Anti-oxidation reinforcement protection is intact

No cracking, spalling, or premature deterioration observed

Overall Conclusion

The Wadi Kuf Bridge is structurally sound and performing in full compliance with the rehabilitation design specifications.

The assessment confirmed:

Adequate stiffness and strength (calibration coefficients < 1.0)

Improved torsional resistance (16.5% enhancement)

Operational seismic-resistant bearings

✅ Excellent elastic recovery (94.2%)

✅ Properly protected and durable stay cable concrete systems

✅ All newly installed elements functioning as designed

Recommendations

Implement a periodic Structural Health Monitoring program for the prestressing systems

Conduct visual inspections of bearings and anti-torsion rings at 5-year intervals

Maintain the cable concrete protection system through regular painting cycles

Assessment Team: LGEngineering Ltd – Structural Assessment Division
Date: October 2009

Libya Projects — The Vision, The Challenge, The Legacy

This was more than an engineering project — it was a defining chapter in my professional life. The Al Bayda Development represented the convergence of visionary ambition, high-level diplomacy, and world-class engineering on a scale rarely seen in modern infrastructure. The journey began in Italy, where a Libyan delegation led by Muammar Gaddafi himself visited the Rieti area. During that meeting, we had the extraordinary opportunity to present our design concepts directly to him and his staff. What started as a diplomatic exchange evolved into a deeper engagement as Gaddafi shared his vision for a new Libya — a nation that would project power, prestige, and modernity through iconic architecture. He wanted buildings that would be remembered for centuries, structures that would define the skyline and the identity of his country. His philosophy was clear: Libya needed symbols of strength and unity. He did not want conventional architecture; he wanted monumental, ambitious, and unmistakably Libyan landmarks. This vision resonated deeply with our team, and we began developing concepts that would capture this spirit — culminating in the design of a 450m rotating skyscraper, a new university, and a parliament complex. The designs were bold, innovative, and structurally ambitious, incorporating advanced engineering solutions including seismic isolation, steel-composite systems, and distinctive geometries. The turning point came when Gaddafi and his delegation reviewed the designs. He was captivated by the vision. The combination of iconic form, structural innovation, and the sheer scale of the development aligned perfectly with his aspirations for Libya. This was the moment the project moved from concept to reality, and we were entrusted with delivering his vision. The partnership that followed was unique and complex. The project brought together the Berlusconi family — with their deep political and business connections — and LGEngineering Ltd, alongside a network of international contractors and subcontractors. The Berlusconi family played a pivotal role in facilitating the high-level political and financial frameworks necessary to advance the project, while LGEngineering led the technical delivery. What followed was one of the most challenging and rewarding experiences of my career. Managing a project of this magnitude involved coordinating multidisciplinary teams across structural engineering, architectural design, MEP systems, and construction logistics. We had to navigate the complexities of working within Libya's political and regulatory environment while maintaining international design standards and quality assurance protocols. The contract documents, subcontractor agreements, and procurement strategies had to be meticulously structured to manage risk and ensure delivery across a portfolio exceeding €4.5 billion. This required extensive coordination with Libyan government ministries, embassy officials, and international partners, alongside the direct engagement with Gaddafi and his inner circle. The Al Bayda Development was intended to establish a new administrative and political capital for Libya — a symbol of national unity, progress, and modernization. The project encompassed high-rise residential towers, institutional buildings, educational facilities, and comprehensive master infrastructure, all designed to create a self-sustaining urban center capable of housing government functions and a growing population. Working alongside the Berlusconi family, international contractors, and the Libyan government, I led a team of engineers, architects, and project managers through every phase — from conceptual design to detailed engineering, procurement, and construction coordination. This experience taught me the true meaning of leadership, resilience, and the power of engineering to shape nations.