Jet fans are vital components of tunnel structures as they assure the air quality as well as safety in case of a fire. These are special equipment rotate with high frequency and require a precision in their support systems so that the rotation takes place safely, without a disturbance.
Eurasia tunnel is an underground tunnel that connects the European side of Istanbul to the Asian side, stretching from one continent to the other. The deepest point of the tunnel is 107m from the sea level. The tunnel consists of a 3.4km long TBM portion and total of 2km long NATM sections. The tunnel has two decks, creating three parts inside the tunnel. The upper deck is used by two lanes from Europe to Asia while the lower deck is used by two lanes from Asia to Europe. The lower part of the tunnel is used a a service duct.
The jet fans of the low deck hang from the deck structure, which is simply-supported with 12m span. The jet fans are supported on vibration isolation units for isolating the high-frequency vibrations induced by operating of the fans.
Senso was commissioned to evaluate the existing design, and finally re-design the isolation units to assure that the jet fans function both in the high and low frequencies induced by the vibration of the slender deck. Senso diagnosed the issues, designed new isolators, produced the isolators in collaboration with Arsan, witnessed the replacement, and provided post-replacement vibration proof tests for the customer.