4.14 km-long, 8 sq m horseshoe section advanced from both ends at 122 m/month/face beneath Ante Lebanon mountains from Aen Zarka to Al Balaa by contractors Banske Stavby of Prievidza, Slovakia and Takla-Weavers of Guernsey, UK. Holed 16th November, 1998. Generally in competent limestone of 9 – 62 Mpa using resin encapsulated rockbolts, steel arches, mesh and lagging. Some dry karst caverns encountered. Maximum overburden 200 m. One 10 m section was supported by micropiles and compensation grouted. Final lining of 20-30 cm-thick monolithic concrete under installation using 10 m telescopic slip formwork. Two vent shafts of 800 mm diameter by 58 m-deep and 108 m-deep installed for emergency escape. December 1999.
