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Monitoring Soil Consolidation

Automated monitoring of soil consolidation collects pore-pressure and settlement readings at regular intervals and automatically posts data, graphs, and reports on a project website. Datasheet

Automated Consolidation Measurements

The AMTS collects settlement plate readings. The Gateway collects piezometer readings. Readings are sent to the GeoCloud server at frequent intervals.

Web Access to Data

The server processes the readings and posts alerts, graphs, and reports on the Geocloud project website. Authorized users have access wherever there is an internet connection.

Advantages of Automation

  • Automation helps control costs and enhance site safety by reducing the need for instrument technicians and survey crews.
  • Automation increases reliability and confidence in the data by obtaining measurements at frequent intervals.
  • Automation presents data graphically on a secure website that is updated continuously.

Piezometers

Piezometers are installed at specified locations and depths within the wick drain grid. When ground conditions permit, the wick-drain rig is used to install the piezometers; otherwise, the piezometers are installed in boreholes. In either case, cable from the piezometer is brought to the surface.

Automation: Pore-pressure readings are automated by connecting a wireless node to the piezometer. Similar to a small data logger, the self-powered node reads the piezometer at regular intervals and transmits the data to an on site wireless internet gateway.

Vibrating Wire Piezometers

Settlement Plates

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. Settlement is traditionally monitored by surveying the top of the riser pipe.

Automation: Prisms are attached to settlement plate risers. An AMTS system measures the elevation of the prisms.

Wireless nodes can also be mounted on the settlement plate riser: a node to monitor a piezometer installed at the same location; or a laser distance meter node to monitor the current fill level.

Settlement plate with four piezometers

Combination installation of settlement plate and four piezometers. A prism and wireless node are at the top of the riser.

Settlement plate with prism

AMTS Monitoring System

The AMTS monitoring system is typically mounted on a gravity-base tower that provides line-of-sight to many settlement plate prisms. The AMTS obtains high precision elevation measurements at regular intervals and transmits them to the internet via a cellular modem.

Wireless Gateway

The wireless gateway forwards readings from wireless nodes to the internet via a cellular connection. It is often co-located with the AMTS.

Both the AMTS and the Gateway can be powered by solar panels.

GeoCloud Server

The GeoCloud server receives measurements sent from the project site. It performs preprocessing operations, such as least-squares adjustments for the AMTS measurements, and then stores the data in a project database.

GeoCloud Website

Each project has a dedicated website and automatically generates graphs, reports, and views such as the contour plot below. Authorized users can access the website with smartphones, tablets, and desktop computers.

AMTS on Gravity Base Tower

GeoCloud Quickview Data Presentation

Trend Plot

This combination plot shows pore-water pressure (top) and settlement. Pore-water pressure increases as the surcharge is placed and then dissipates over time. Settlement follows the decrease in pore-water pressure and then shows a slight rebound when the surcharge is removed.

Consolidation graph - pore pressure and settlement

Contour Plot

This video animates a series of contour plots derived from settlement plate data. Red shows the least settlement, blue shows the most. The surcharge was placed from left to right. The plot also shows data for piezometers, tiltmeters, and vibration monitors.