Inclinometers

Applications

Applications for vertical inclinometers include:

• Monitoring slopes and landslides to detect zones of movement and establish whether movement is constant, accelerating, or responding to remedial measures.
• Monitoring diaphragm walls and sheet piles to check that deflections are within design limits, that struts and anchors are performing as expected, and that adjacent buildings are not affected by ground movements.
• Monitoring dams, dam abutments, and upstream slopes for movement during and after impoundment.
• Monitoring the effects of tunneling operations to ensure that adjacent structures are not damaged by ground movements.

Applications for horizontal inclinometers include:

• Providing settlement profiles of embankments, foundations, and other structures.
• Monitoring deformation of the concrete face of a dam.

Portable Inclinometer Systems

Inclinometer Casing

Inclinometer casing is permanently installed in a borehole that passes through suspected zones of movement. Inclinometer casing can also be embedded in fill, buried in a trench, cast into concrete, or attached to a structure. Important features of casing include the diameter of the casing, the coupling mechanism, groove dimensions and straightness, and the strength of the casing.

Portable Traversing Probe

The traversing inclinometer probe is the standard device for surveying the casing. It is economical, since it can be carried from site to site. The traversing probe obtains a complete profile because it is drawn from the bottom to the top of the casing. The first survey establishes the initial profile of the casing. Subsequent surveys reveal changes in the profile of the casing if movement has occurred.

Portable Readout

A portable readout is used to record the surveys obtained with the portable probe. Advance readouts store readings in solid-state memory, eliminating pencil, paper, and transcription errors, and transfer the data to a computer for processing.

Graphing Software

Inclinometers generate more data than do other types of sensors. A single survey may generate several hundred data points. Over time, tens of thousands of data points are manipulated, reduced, graphed, and archived. Slope Indicator's DigiPro software for Windows is designed to speed this process. You can download a trial version of the program.

In-Place Inclinometer Systems

Inclinometer Casing

Inclinometer casing is also required for in-place inclinometer systems.

Fixed In-Place Sensors

In-place inclinometer sensors are placed at specific depths to span a zone of suspected movement. They are left in-place (unlike the traversing probe) and usually monitored continuously to ensure safety. The costs for an in-place system are greater because the sensors are dedicated to a particular installation.

Data Loggers

A data logger is used with in-place sensors. It monitors continuously and can trigger an alarm when it detects a change or rate of change that exceeds a preset value. Slope Indicator typically supplies Campbell Scientific data loggers.

Automated Processing

In-place inclinometer systems connected to data loggers generate even more data, and often the data must be processed and distributed as soon as it becomes available. Slope Indicator's Argus web-based monitoring performs this task, automatically processing the readings, checking for alarms, and generating graphs and reports.

Spiral Checking

Spiral Sensor

A spiral sensor provides readings that can be used to correct inclinometer data obtained from spiraled casing. Spiral surveys are recommended when the installation is very deep, when inclinometer readings indicate movement in unlikely directions, or when difficulties were experienced during installation.