Netivei Israel, Israel National Roads Company completed the excavation of the Harel Tunnels on Road 1 (Jerusalem-Tel Aviv Highway) beneath the Harel Interchange near Castel and Mevasseret Zion.
The tunnels are part of the project to upgrade Road 1 between Sha'ar Hagai and Jerusalem. The 650 meter long twin tunnels, 15m in diameter, which run beneath the Harel Interchange at Mevasseret Zion have three lanes in each direction and broad shoulders.
The tunnels were excavated at depth of about 40 m underground. They will include emergency passages between tunnels, and advanced fire safety and traffic control measures.
The twin tunnels will replace the old Harel Bridge and form part of the project to upgrade the Jerusalem – Tel Aviv road. The tunnels, once completed, will cut the journey time between Tel Aviv and Jerusalem and reduce gasoline consumption and air pollution.
The vast amount of stone mined from the tunnels has been recycled to fill the Arazim Valley to the east. The entire project will cost NIS 2.5 billion. The overall project also includes cutting out the notoriously dangerous Motza curve beneath Mevasseret Zion and instead building two parallel 800 meter bridges, each with three lanes. These bridges will make the journey to Jerusalem faster and safer.
Excavation works of the first tunnel were completed within only a year and a half, and were executed using the drilling-explosion technique. With this technique, the contractor was able to progress at rate of about 4-6 meters per day, depending on the hardness of the rocks along the path. The tunnel is excavated in a manner where an explosive is inserted into holes that are drilled in the rock.
After controlled explosion, the rocks and the dirt are removed outside in order to allow further progress while adhering to the most stringent work safety rules. Support work and concrete spraying on tunnel walls for preventing collapse are executed concurrently.
Works are executed by Hofrey HaSharon - Elektra. A total of quarter million cubic meters of dirt and rocks will be excavated in both tunnels - a quantity that requires 14,000 trucks to be cleared", added Ofra Rahav, VP of Development and Sustainability in Netivei Israel. "Due to the vast volumes, new Road 1 was designed and is executed according to advanced environmental standards. This way, inter alia, we are working towards balancing excavation and filling materials. The dirt excavated in the tunnels is used for filling Wadi Arza nearby that should be elevated for further pacing of the new road. This eliminates the need in costly and contaminating transportation of thousands of trucks loaded with dirt and rocks."