Inclinometer training

GEO-Instruments is installing inclinometers, MPBXs ( Automated borehole extensometers), and UMPs (utility monitoring points) for the LAWA & LAMP Enabling project at LAX in California. The instrumentation is for a microtunnel to be driven under existing structures at Aviation Boulevard. GEO’s full service contract includes drilling, borehole logging, instrumentation supply, installation, commissioning, and training for…

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Monitoring Structures above Tunnel

Baltimore, MD 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.

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Settlement and Tunnelling

Bellevue Tunnel, WA.  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 and LidLink antennas transmitted measurements to a GeoCloud…

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Tunnel Monitoring

Bethesda, MD GEO monitored a WMATA tunnel structure with 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.

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Wireless Logger - in street installation for Piezometer

Bellevue Tunnel Piezometers GEO engineer sets a wireless datalogger to transmit hourly readings of a piezometer. Automation improves safety for technicians and eliminates traffic disruptions. Piezometers were installed along the tunnel alignment collocated with observation wells and inclinometers at 10 locations. All were automated with dataloggers and wireless communications. Readings were displayed on a dedicated…

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GEO monitored a 32-foot deep excavation and a WMATA metro tunnel adjacent to the excavation in Washington DC. The SOE consists of drilled soldier piles braced with whalers and rakers. GEO’s technician can be seen on the wall. Monitoring prisms, a few visible in this photo, are mounted at the top of each pile around…

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South Portal Sound Wall

The East Link extension adds 14 miles and 10 stations to Sound Transit’s light rail system, carrying commuters between Bellevue and Seattle. This is a conceptual drawing of the south portal site, where the light rail enters the Bellevue Downtown Tunnel. This was the actual south portal site, cleared, graded, and ready for excavation. A…

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Rosslyn-station-project

Project Overview Construction of twin residential and commercial towers adjacent to the Rosslyn metro station involved demolition of an entire block of existing buildings, blasting and excavation for deep foundations, and finally the construction of the towers. The station, ventilation shafts at each end of the station, a long escalator, and three high-speed elevators were…

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MTA East Side Access Tunnels

Project Overview New York’s East Side Access project is designed to bring the Long Island Rail Road from Queens to Grand Central Terminal in Manhattan. Because the project involves tunneling under high value real estate, designers specified that the route be closely monitored for possible settlements. Monitoring Challenges The selected locations for monitoring, busy streets…

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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 the tunnel.…

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