Traditional monitoring involves instrument technicians and survey crews walking the site. Each crew reports separately, so measurements must be consolidated. Site visits are expensive so measurement frequency is typically reduced to control costs.
- Automation eliminates or reduces the need for site visits by technicians and survey crews. This reduces costs and enhances site safety.
- Measurements are collected automatically and reported graphically on a secure website that is updated continuously 24/7.
- Automation obtains measurements at frequent intervals, increasing both reliability and confidence in the data.
GEO-Instruments automated consolidation monitoring system consists of piezometers, settlement plates, laser extensometers, AMTS system, GeoCloud gateway, and a QuickView website.
Piezometers are installed at specified locations and depths within the wick drain grid, typically by the same rig installing the wick drains. Piezometers can also be installed in pre-drilled boreholes.
In either case, cable from the piezometer is brought to the surface and connected to a Geocloud piezometer node. The self-powered node obtains pore-pressure readings at regular intervals and transmits them wirelessly to a GeoCloud gateway.
The piezometer in the photo will be enveloped in wick-drain material and then installed by the wick-drain rig.
Settlement plates are installed at specified locations within the wick drain grid. A basic settlement plate consists of a plate and a riser pipe that can be extended upwards as fill is placed.
Elevation measurements: The riser is topped with an L-Bar Mini Prism. An AMTS system tracks the elevation of the prism to provide settlement data.
Surcharge height: A wireless GeoCloud laser distance meter can be installed at the top of the riser to measure the distance to the current level of the fill. Measurements are transmitted to the GeoCloud gateway. Offsets are adjusted when riser is extended.
Piezometer measurements: When a piezometer is installed, a wireless piezometer node is also be installed on the riser pipe.
AMTS System & GeoCloud Gateway
The AMTS (automated motorized total station) is a high precision optical monitoring system that records the elevation of the settlement plate prisms. One AMTS system can track many prisms.
The AMTS is mounted on a gravity-base tower placed with line-of-sight to the settlement plate prisms. It obtains measurements at regular intervals.
The GeoCloud cellular gateway is typically placed in the same location. It receives readings from the GeoCloud nodes.
AMTS system and the GeoCloud gateway use cellular connections to transmit measurements to the QuickView website. Both can be powered by solar panels.
Measurements transmitted from the site reach the GeoCloud server that runs the QuickView website. The server performs preprocessing operations, such as least-squares adjustments for the AMTS measurements, and then forwards the data to the QuickView website.
Each site has its own QuickView website. Users see preconfigured plan views, plots, and reports that are generated on demand, always using the most recent data. This ensures consistent calculations and scales. QuickView also supports adhoc graphs and tabular data for downloading to excel or modelling tools.
QuickView plot shows a spike in pore-water pressure as surcharge material is placed.
Quickview plot shows settlement resulting from decrease in pore-water.
Quickview used data from settlement plates, shown as yellow diamonds, to generate a settlement contour plot for this site. Red shows the least settlement, blue shows the most. The plot also shows data for piezometers, tiltmeters, and vibration monitors.