Milan Metro – Line 4

Milan, Italy – Metropolitan Transportation Infrastructure

TECON has been engaged by Metro Blu scrl, working for Metropolitana Milanese, to provide comprehensive detailed engineering design services for Milan’s ambitious Metro Line 4 project. This critical infrastructure development represents one of the most significant urban transportation expansions in Milan’s recent history, connecting Linate Airport directly to the city center while extending metro coverage to previously underserved areas of the city.

In the last decade, the city of Milan has undertaken an ambitious expansion of its metro network, building new lines to meet the growing transportation demands of its metropolitan area. Following the successful completion of Line 5, the construction of Line 4 commenced as a vital connection linking Linate Airport to the city center and extending metro coverage to the peripheral areas of Milan that were previously not served by the underground network. This project represents a significant engineering challenge, requiring careful integration with Milan’s dense urban fabric and historic architecture.

Project Scope

TECON has developed detailed engineering designs for approximately ten metro stations covering the western section and city center of Line 4. Each station design has been executed with meticulous attention to the surrounding built environment, whether integrating with contemporary developments or respecting the historical character of ancient structures. The engineering work encompasses all aspects of underground station construction, from initial excavation support through final structural completion.

Earth Retention and Foundation Systems

• Comprehensive detailed design of earth retaining structures utilizing anchored slurry wall technology for deep excavation support
• Micropile foundation systems engineered to provide additional structural support in challenging soil conditions
• Ground anchoring systems designed to resist lateral earth pressures during construction phases
• Temporary strut systems providing internal bracing for excavation stability

Permanent Station Structures

• Complete reinforced concrete structural design for all station boxes, platforms, and passenger circulation areas
• Ventilation shaft structures and emergency access wells designed to meet stringent safety requirements
• Integration of architectural finishes and MEP systems within structural framework
• Waterproofing and drainage systems to ensure long-term durability below the water table

Temporary Works and Construction Support

• Engineering design of temporary steel bridges maintaining surface traffic during underground construction
• Protective decking systems allowing urban activities to continue above active excavation sites
• Construction sequencing strategies minimizing disruption to Milan’s busy urban environment
• Detailed bar bending schedules and reinforcement shop drawings for efficient on-site construction

Engineering Approach

The TECON engineering team has adopted a comprehensive approach that extends beyond traditional design deliverables. Throughout the construction phase, our engineers provide continuous technical assistance to contractors, ensuring that complex design details are properly executed in the field. This collaborative approach includes regular site visits, technical clarifications, and problem-solving support during excavation and structural construction activities.

During the commissioning phase, TECON continues its involvement by providing specialized assistance to both contractors and the owner, Metropolitana Milanese. This ensures smooth handover of the completed facilities and addresses any technical issues that arise during final testing and system integration. Our commitment to project success extends through the entire lifecycle, from initial concept through operational readiness.