Jun 30, 2022
While advances in digital technology have allowed greater access to data, the components of a successful monitoring project have ultimately not changed.
Instrumentation and the analysis of the data collected provide a reliable method to verify assumptions made early in the design process, to establish a quantifiable, measurable, and reportable method of oversight throughout all phases of an engineering project—whether during the design phase or during operation. Risk can be assessed and mitigated at all stages, as new information is gleaned throughout the course of a project.
But not all instruments are implemented all at once, and instrumentation and software functions will change to suit the needs of the various stakeholders of the project, as the project itself evolves.
It is therefore of vital importance to maximize efficiency, to pare down bulk data and provide only the information needed at any given time.
Mindset
Monitoring is the collection of geotechnical key parameters like pore pressure, displacements, and earth pressures in order to answer specific questions that are related to the site investigation—the stability, the short-term and long-term performance, the construction process and the effects on adjacent structures. Every instrument needs to have a purpose.
Toolset
As you know, the range of monitoring instruments and techniques, either in-ground, on-ground or above-ground have multiplied over the recent years. In-Place inclinometers and ShapeArrays have now mostly replaced manual inclinometer surveys. Settlement profiles can be monitored using horizontal ShapeArrays. Fibre optic can be used for distributed sensing of strain, temperature, and vibration. Geodetic instruments such as robotic total stations and global navigation satellite systems (GNSS) are very common. Ground-based Radars, UAV Lidars and UAV photogrammetry are gaining adoption. Satellite InSAR is an established remote sensing method as well.
There are many tools in the toolbox. Not every monitoring project can afford all of them. To prioritize which one to use, ask the question: what do I want to monitor?
Evolution
Not everything will be implemented immediately at the beginning of the project. Instruments will be deployed during the site investigation, construction, and operation stages of the project. For example, during construction, some instruments will be installed in the foundation of the future water dam or tailings dam or in the ground behind a future retaining wall or on buildings along the path of a future tunnel. Dataloggers will already be installed at this stage as several projects require establishing a baseline a few weeks or months prior to the start of construction.
Then as the project evolves, additional instruments and data loggers will be installed and the data visualization software will be implemented, and the visualization dashboard screens will be configured and improved to suit the needs of the various project stakeholders.
Collaboration
Many groups—owners, designers, contractors, manufacturers, and integrators—are all equally important in the collaborative process to ensure a successful geotechnical monitoring program.
The owner must recognize in advance the benefits, including the savings, that result from a properly designed and implemented geotechnical monitoring program. The owner must mandate the designer to plan and specify a suitable program that provides those benefits.
The contractor recognizes the importance of the performance monitoring program and how it will not only be useful for the owner, but also for themselves as a tool for risk management and cost control. The contractor must also facilitate the implementation of the monitoring program and collaborate with the designer and the integrator so that the program will be implemented in the most efficient way with minimum disturbances to the construction process.
The manufacturers’ role is to collaborate with all stakeholders and to make an effort of understanding the objectives of the monitoring program to assist in selecting the most suitable type of instruments, data loggers and data management and visualization software. The manufacturer should also always be in listening mode to take every opportunity to improve their instruments and make them even more robust and easy to install and troubleshoot.
Finally, the integrator has a very important role in installing and maintaining the geotechnical and geodetic instruments, dataloggers, connectivity and remote sensing and integrating them into the data management and visualization software. The integrator is in constant contact with the contractor, the designer and the owner who are the final users of the data.
Ultimately, the four keys of smart geotechnical work in tandem to mitigate as much risk as possible to result in more successful projects that run on schedule and on budget.
This blog is a part of a series that recaps the topics explored in Digital Evolution of Geotechnical Monitoring presented by Terra Insights. Watch the webinar on-demand to learn how advances in monitoring technology have had wide-ranging impacts, from the design of instrumentation sensor components to wireless data acquisition and connectivity to space-based satellite imagery.