Advanced machines like this one — which sprays pressured concrete known as shotcrete — played an instrumental role in constructing East Link's Downtown Bellevue tunnel

Advanced machines like this one -- which sprays pressured concrete known as shotcrete -- played an instrumental role in constructing East Link's Downtown Bellevue tunnel

Advanced machines like this one — which sprays pressured concrete known as shotcrete — played an instrumental role in constructing East Link's Downtown Bellevue tunnel