Project Outline The Tehran metro system is a project of immense national
importance which, when completed, is destined to radically transform Tehran's
transportation network. Due to the complex nature of the project, the tunneling
program encompassed a variety of innovative design and construction techniques.
The Tehran metropolitan area has a diverse and challenging geology, including
soft and sandy soils. An important success factor for Tehran metro's tunneling
program was, therefore, that the challenges posed by the geology be identified
up-front on a segment-by-segment basis, and effective solutions be then derived
and implemented to overcome potential difficulties. Specifically, efficient
underground system waterproofing techniques had to be used to provide completely
The Tehran metro's tunnels were executed via open-trench,
Austrian/shotcrete supported and concrete segmental lining methods.
Scope of Work
- Involved: Drilling and contact grouting to strengthen the soil contact with
the tunnel's segmental lining
- Drilling and grouting in order to make an
impermeable curtain to prevent underground water seepage and consolidate
decompressed zones caused by underground excavation.
- Ongoing control of
construction specifications prior to and after grouting operations.
waterproofing tests following investigation drilling and upon completion of each
stage of grouting.