Mounting a Tiltmeter to Concrete, Steel and Shotcrete Walls

A tiltmeter is a practical and effective way to monitor wall movement on engineering projects in Western Australia. But whether installed on a retaining wall or tunnel lining, it’s efficacy depends almost entirely on how and where it is mounted.

A poorly installed tilt sensor will introduce noise, drift and incorrect readings. Following best practices for mounting and adjusting your approach to the type of surface in question will reduce irregularities down the line.

This guide outlines best practices for mounting tilt sensors. To discuss wall and tunnel deformation monitoring with a Monitel consultant, click here.

Mounting to Concrete Walls

Concrete is one of the most common surfaces in projects where we would use a tiltmeter. Examples include retaining walls and bridge abutments.

Key Considerations

• Surface Preparation
• Fixing Method
• Alignment
• Environmental Protection

Our consultants will ensure the monitored wall is properly prepared for monitoring, cleaning and adjusting to create a stable contact point. From there, we mount the sensor using anchor bolts or threaded inserts (mechanical options always chosen in longer term programs).

Once mounted, sensors are aligned in accordance with system design. This is usually perpendicular to the wall face or along the axis of expected rotation. We complete the process by accounting for any environmental forces that could damage the sensor and/or its data.

Mounting to Steel Structures

Walls, sheet piles and frames made of steel are common in excavation support systems, which make up a large portion of our tiltmeter monitoring work. These installations typically involve greater vibration and more dynamic loading.

Key Considerations

• Attachment Method
• Cable Management
• Vibration Management
• Thermal Expansion

We account for those complexities from the beginning, selecting a bolted or mounted attachment method to suit the structure. All cabling is managed in a way that limits any noise it could introduce to your readings. If necessary, vibration management measures are installed alongside the sensor.

Steel is, of course, prone to contraction and expansion with temperature changes and our team will provide ongoing data interpretation support to help you account for data differences.

Mounting to Shotcrete Walls

Shotcrete is found in tunnels, shafts and, similar to steel, excavation supports. It’s a varied surface and requires a much more considered approach to ensure the sensor remains stable and accurate during the monitoring period.

Key Considerations

• Surface Irregularity
• Fixings
• Early-Stage Installation
• Ongoing Stability

Sensors can be installed too soon after shotcrete application. Monitel takes care in ensuring the material has sufficiently cured and can provide a stable base. We also choose installation locations to maximise stability and minimise the effect of any cracks or degradations the shotcrete suffers over time.

As mentioned, shotcrete surfaces are often uneven so our consultants may consider using a mounting plate to create a flat point of contact for the sensor. Depending on the strength of the shotcrete layer, we will mount the sensor with either anchors of chemical fixings.

How Monitel Supports Tilt Sensor Installation

Monitel consultants provide end to end support and design of tiltmeter monitoring systems. Our services include:

• Sensor selection and system design
• Site specific installation planning based on wall type and conditions, including mounting hardware where needed
• Installation and alignment
• Integration with new or existing data systems
• Ongoing support with data interpretation, troubleshooting and compliance reporting

We leverage our partnerships with Wisen, Viotel and Osprey Measurements to provide WA operators with market leading instrumentation. Nonetheless, we take great pride in our brand and product agnostic approach and will always choose the technology that serves your needs, not our bottom line.

Get in Touch to Arrange a Consultation

Mounting a tiltmeter correctly is essential in gathering meaningful and valid data. Whether working with concrete, steel or shotcrete, the goal must be the same: create a stable, reliable connection that provides a true reflection of structural movement.

Monitel consultants specialise in creating surface and site specific plans to achieve that goal.

To discuss wall or ground movement monitoring with one of our consultants, click here.