projects
I-5 Undercrossing
I-5 Undercrossing for Sound Transit This wide-angle photo shows excavation of one of the four pits (left), a scan station (middle), and one of the 400-foot long retaining walls (background). Project Overview Sound Transit’s U-Link project extends the regional light-rail system from downtown Seattle to the University District, via a 3.5 mile tunnel. The most…
Read MoreOil Storage Tanks
Recommissed Oil Storage Tanks Project Before an an oil storage facility could recommission some retired tanks, plant engineers engineers had to address concerns about the pile foundations of these tanks. Specifically, they needed early warning of settlements or differential movement of the tank foundation as the tanks were filled. GEO-Instruments provided a real-time monitoring system…
Read MoreOld South Church
Old South Church Project Overview Old South Church is a national historic landmark in Boston. It was built in 1873 on a wooden pile foundation. In 2008, high pressure grouting operations on a nearby subway station caused some of the piles to shift and opened a 70-foot long vertical crack in the east wall of…
Read MorePier Stability
Pier Stability Project Overview Nearby dredging operations posed a potential risk to this pier at a container ship facility. To monitor the pier, GEO-Instruments provided weldments for the underwater load cells and a wireless, battery-powered logging system for data collection. The logging system was installed flush with the pavement of the pier to avoid obstructing…
Read MoreHines Bridge
Hines Bridge Overview In November 2008, a heavily loaded barge battling strong currents collided with a bridge pier. The collision damaged the pier and caused misalignment of the swing span, which would no longer close properly. Safety concerns forced the Massachusetts Highway Engineers to close the bridge to traffic. The engineers then designed a series…
Read MoreLincoln Tunnel
Lincoln Tunnel Project Overview The Ferry Terminal at Pier 79 on Manhattan’s west side was constructed just 60 feet above the three tubes of the Lincoln tunnel. The project involved driving of pipe & sheet piles for the new ferry terminal and docking facilities. Some of the pipe piles were driven within 15 feet of…
Read MoreDulles Airport
Dulles Airport Work 2003 The Automated People Mover project at Dulles International airport involved nearly two miles of tunneling. Large excavations were required for stations at the main terminal and the three mid-field terminals. The station at the main terminal involved a 50-foot cut and extensive underpinning of the terminal. Monitoring Requirements Monitor support of…
Read MoreRetaining Wall Failure
Castle Village Wall Failure 2005 When the Castle Village retaining wall failed, 41,000 cubic yards of rock, soil and trees slumped onto a major urban highway. The failure closed the highway and endangered nearby apartment buildings. The photo above shows the scale of the failure, some months later. The highway has been reopened, debris cleared,…
Read MoreLA Outfall Sewer
LA Outfall Sewer Project Overview The Lower North Outfall Sewer served as one of Los Angeles’ primary wastewater tunnels for more than 70 years, but inspections revealed that the nine-mile long tunnel was at the point of failure at several locations. Corrosion had reduced the original 14-inch thick lining to just a few inches, and…
Read MoreBear Mountain Bridge
Bear Mountain Bridge Project Overview Bridge engineers added “helper” strands on this 1924 suspension bridge to counter load shedding by the main suspension cables. GEO-Instruments installed special strain gauges on the helper strands and anchors. These would be used to monitor the performance of the helper strands and to detect any further load shedding of…
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