The navigation module automatically keeps track of the TBM’s position in real time with respect to the theoretical axis.
A motorized total station fixed on the tunnel lining determines the coordinates of two prisms on the TBM, using a reference prism whose coordinates are known. The coordinates of these two prisms are then used to calculate the TBM’s position.
A bi-axis inclinometer determines the roll and pitch of the TBM. These data are used to determine the front position of the TBM and to check the accuracy of measurements from the theodolite on the two navigation prisms. The data are transmitted to the system’s computer to display the front and rear position of the machine on a screen in the control cabin.
Navigation system schematic
- Constant control of TBM’s position
- Accuracy and display of axis
- Simple and reliable.
Screen in control cabin
STEERING and PILOTING
Ring sequence pre-calculation software
This software pre-calculates the ring sequences according to the trajectory and generates a daily laying plan with the characteristics of the adopted catching curve, ring positions and associated steering orders for the pilot.
The advantage of this piloting solution is that it enables a new catch-up curve to be regularly recomputed according to the TBM’s position and thus to remain as close as possible to the excavation axis.
The steering principle entails five steps.
Example laying plan
Ring sequence pre-calculation principle
Piloting assistance display
This module lets pilots follow the steering orders from the ring sequence pre-calculation software, which set the change in the horizontal and vertical stroke difference between the thrust cylinders.
The piloting assistance interface constantly indicates on screen to the pilot a point representing the drift between the desired position (target) and the current position of the TBM.
The highly sensitive sensors ensure fine control of piloting and a very regular and precise curve.
Automatic steering option
The automatic steering option enables precise and accurate distribution of thrust in the different groups of cylinders in line with the steering orders.
The monitoring module is a data acquisition system that records all parameters from the sensors on the TBM. It can also acquire parameters from other automation systems, such as a mortar plant, conveyors or a slurry plant.
This tool provides animated synoptics in real time for effective supervision of all tasks during excavation phases, and lets you save and print graphs, generate daily reports, export and record data in Excel format and set alarms with e-mail or text alerts.
All synoptics and reports are accessible on line.
Example synoptics and reports
The database tool collects and stores the information from the data acquisition system in order to be able to, beyond real-time visualization, analyze information afterward.
A specially designed interface enables data to be analyzed over long periods in the form of graphs or synoptic tables.
Parameters can be set for specific tables or graphs, for example to show production parameters, consumables, topographic data, the number of rings built per day or excavation and building time.
- All information about TBM production in one place,
- Quality assurance,
- Real-time and near-real-time analysis,
- Post-operation analysis,
- Facilitated feedback,
- Facilitated project completion reports.
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Additional tools let you exploit all excavation information:
Daily production reports to optimize TBM production and provide feedback for future projects (analysis of TBM boring time and coefficients of use in line with AFTES recommendation).
Example production report and AFTES pie chart
Integration of surface settlement data, displays and an associated analysis tool, allowing you to analyse settlement during passage of the TBM and relay information to production teams so that piloting can be adapted in the event of a problem.
Example of settlement
data during passage of the TBM
and position with respect to axis
Tool for recording manufacturing information about the segments making up the ring (RFID chips, barcodes or QR codes read out using a scanner connected to the database) to keep track of stock available on site, record segment positions in the tunnel and keep a check on the manufacturing process.
Segment serial numbers
Tool for checking and analyzing tunnel cracks using a tablet connected to the database, enabling analysis and reporting of segment anomalies.
Segment crack detection screen
Representation of the layout and position of the TBM in real time on Google Maps to keep track at all times of its exact position relative to surface buildings.