Value engineering and its application in the Tehran-Shomal freeway project

The Tehran-Shomal freeway is a significant road project in the Middle East, connecting Tehran to northern Iran. Spanning 121 kilometers, the project includes four sections, 195 tunnels, and 83 bridges. The unique topography of the Alborz Mountains necessitates various structures. Value Engineering is crucial in minimizing construction time and costs while maintaining quality. This paper focuses on the application of Value Engineering in the Tehran-Shomal freeway project, specifically on the 27-30 east lane variant. Alternative variants were considered to address potential challenges. The Analytical Hierarchy Process was used to compare three alternatives, leading to the replacement of the initial plan with an integrated long tunnel. This offered numerous advantages, including cost and time reduction, improved route geometry, environmental preservation, reduced geotechnical issues, and increased safety. A significant milestone was the successful implementation of the alternative variant, passing under the west lane in specific sections. This required extensive instrumentation, controlled blasting, and a customized support system. This article presents illustrations of the plans and tunnel construction under special circumstances, along with a detailed technical-financial comparison between the integrated long tunnel and the combined option of bridges, tunnels, and false tunnels in variant 27-30.