infrastructure
Prado Dam Basin
Prodo Dam Basin Project The USACE enlarging the flood control basin and building a dike to enhance flood risk management at Prado Dam. The basin is designed to accomodate a 200-year event. Monitoring Requirement Engineers needed to monitor settlement, total pressure, and pore-water pressures. Implementation GEO installed a wireless, solar-powered logger, three settlement cells, an…
Read MoreCaltrain Tracks
Caltrain Tracks GEO’s AMTS is monitoring Caltrain track during adjacent construction. The dots of light are prisms installed on the track. Rail clip prisms are installed in pairs at 15-foot intervals along the track. This photo shows only the inside prisms. Pairs of road prisms at the road crossing. Monitoring prism pairs provides measurements of…
Read MoreTerminal Expansion
Denver Airport Expansion Project Denver International Airport added 39 gates to the existing terminals, increasing capacity by 30%. Monitoring Requirement Existing structures were monitored for movement as excavation and construction takes place. GEO was contracted to monitor four structural columns on Terminal C, which was undergoing a 16-gate expansion. Implementation GEO-Instruments installed two L-bar prisms, one…
Read MoreSlope Monitoring
Slope Monitoring at Snoqualmie Pass Project Rockslides and snow avalanches at Snoqualmie pass have caused frequent closures of I-90, so State and Federal agencies embarked on an avalanche bypass project. Monitoring Requirements WSDOT needed instrumentation for steep slopes directly above a work area. GEO installed 22 instrumented rock dowels. An AMTS system was also installed.…
Read MoreAqueduct Retrofit
Aqueduct Retrofit The ProjectThe Mokelumne Aqueduct, some 87 miles long, consists of three large-diameter pipes,constructed in 1929, 1949, and 1963. The aqueduct carries water from the Sierra Nevada foothills to the East Bay Area, providing nearly 80% of the area’s water supply. The RequirementThe aqueduct underwent a seismic retrofit of support bents, expansion joints, and…
Read MoreLight Rail & Utilities
Light Rail & Utilities Project GEO monitored Sound Transit assets and an SPU water line during ground improvement work on an adjacent property. Instrumentation Instrumentation included automated vibration monitors for the water line and an AMTS system to monitor the Sound Transit assets.
Read MoreTunnels & Structures
Tunnel Construction & Surface Points GEO monitored an existing train tunnel as work proceeded on a new sewer tunnel. The AMTS in the photo was monitoring surface points, while another AMTS was monitoring within the tunnel. Other instrumentation included shape arrays, piezometers, extensometers, and automated vibration monitors.
Read MoreTunnelling & Settlement
Tunneling & Settlement Monitoring The Bellevue tunnel was aligned with a major thoroughfare. To monitor possible settlements, GEO-Instruments installed borehole extensometers above the tunnel centerline and arrays of road prisms across the road. Photo shows installation of a road prism. Borehole extensometers were terminated flush with the surface using a LidLink antenna. Measurements were transmitted…
Read MoreMetro Tunnel
DC Metro Tunnel GEO’s deployed an automated monitoring system in a WMATA tunnel. The system included strain gages, convergence gauges, tiltmeters, vibration monitors, and AMTS. The AMTS and prisms are clearly visible in the photo on the right. Also visible is one of the eight vibration monitors and wall-mounted geophones.
Read MoreTunnel & Piezometers
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.…
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