Piezometers along Tunnel Alignment

Piezometers were installed in the roadway above the Bellevue tunnel alignment. The instruments were collocated with observation wells and inclinometers at 10 locations. All were automated with wireless dataloggers that were capable of transmitting data through the inspection plates.

Piezometer readings were transmitted hourly and displayed on a dedicated project website. Groundwater levels did not fluctuate much in the dense till, but some instruments detected draining of perched water by probe drilling ahead of the excavation.

Automation improved safety for the technicians and eliminated the need for traffic control.