Technology is transforming the management and rehabilitation of Italian tunnels, increasing their safety and lifespan.
By Paul Colbert
Improving the health of Italy’s vast tunnel network is an important but time-consuming job which is vital to ensuring the safety and sustainability of these critical infrastructure assets.
More than 2500km of tunnels criss-cross Italy, enabling a practical pathway for transport links to negotiate the country’s rugged, mountainous terrain.
But tunnels built during the 1960s and 1970s needed assessment and rehabilitation work to ensure they continued to comply with the relevant Italian guidelines.
Tecne Systra-SWS Advanced Tunnelling is a leader in the field of tunnel design and it bears the responsibility of carrying out the required assessment and rehabilitation work.
The company was committed to finding a digital solution for assessing and designing structural renewal and reinforcement and turned to Seequent and Bentley’s connected suite of products to help.
Italy is home to more than 2500km of tunnels, many of which were need of assessment and maintenance work. Techne-Systra adopted a digital approach for this large and complex piece of work to ensure a sustainable future for the infrastructure.
BIM Manager, Ana Emiliano dos Reis said the company had increasingly realised the importance of taking a digital route to analysis and intervention. A project team determined that it was possible to transition to 3D modelling and digital delivery to meet all project requirements with help from Bentley and Seequent products.
They chose Bentley’s Open Tunnel Designer (OTD) not just for its ability to create detailed 3D tunnel models, but also because of its seamless integration with Seequent’s geological modelling tool Leapfrog Works and geotechnical analysis tool PLAXIS, enabling an all-in-one connected workflow for modelling, design and analysis.
“Going digital in the design phase allowed us to increase the capability of integration and valuation for a better survey data interpretation to support design decisions,” Emiliano dos Reis said.
The design and construction information model became the basis on which it was then possible to implement a digital twin asset information model for facility management in a way to extend asset lifespan, reduce lifecycle costs, and minimise the risks associated with asset failure, she said.
This video highlights how Tecne Systra, a leader in motorway infrastructure design in Italy, is leveraging OpenTunnel Designer for 3D modeling and digital delivery. Discover how their innovative workflows integrate geological, geotechnical, and structural models to enhance the safety, compliance, and longevity of Italy’s existing motorway tunnel
An all-encompassing workflow
Emiliano dos Reis said using the connected Bentley and Seequent suite allowed the team to create a workflow which delivered a 3D OTD tunnel model capable of connecting to other models such as Leapfrog (geological), PLAXIS (geotechnical) and ProStructures (steel structure). This interoperability between Seequent and Bentley’s tools was a key component of their path wish list.
In their workflow, survey data such as that from borehole tv cameras, is first imported into Leapfrog to create a surface model that simulates the voids in the back of the crown, as well as the sub-thicknesses of the existing lining. The survey data from the flat jacks and core drillings is also imported to render numerical models with specific ranges for the compression stress values. Leapfrog is also called into play to create the soil models. All these different models are exported into OTD so all inspection and investigation data can be evaluated quickly and easily, to support faster decision making.
“By using 3D geological models for the borehole tv camera, flat jacks, and core drilling compression test, we were able to integrate and evaluate the survey data into a central model produced with OTD,” Emiliano dos Reis said. “This improves and reduces time on the interpretation of the existing state of the tunnel by 30% in comparison with traditional methods.”
OpenTunnel Designer reduced modeling time by 25% and project delivery time by 21.5%.
Interoperability expressed in real world savings and cost reduction
This streamlined workflow also enables teams to consider more options for potential solutions and interventions, which has reduced tender costs and improved design efficiencies by 20%.
“For example, the interoperability between Leapfrog, OTD and PLAXIS allows us to export geometric tunnel information and respective material and soil reinforcement into PLAXIS to simulate as-built excavation phases, proposed demolitions, and the rebuild of the lining,” Emiliano dos Reis said.
The combination of Bentley and Seequent applications had resulted in a 21% reduction in model time, saving €26,533 in resource hours costs.
Some models have also been employed for construction assistance, providing site coordinates for precast segment installation. And the use of a common data environment has granted team members swift access to all the project data and information in one centralised system, improving coordination, collaboration and teamwork, Emiliano dos Reis said.
Working in an integrated digital platform reduced time for clash avoidance between structural and waterproofing and drainage collection systems by 30%.
Future-proofing Italy’s underground highways
The tunnel lining interventions enabled by Seequent and Bentley will help extend the lifecycle of many existing tunnels on Italy’s road network, Emiliano dos Reis said.
Meanwhile the digitisation of survey data has created a model which can be updated in the cloud and used for a variety of scenarios in the future, including asset management, inspections, IoT monitoring and stakeholder engagement.
Stakeholders will be able to verify the performance and health of every tunnel through real time data collection, so reducing hazards, improving safety, extending tunnel lifespan and ultimately keeping Italy’s traffic flowing smoothly.
Tecne Systra-SWS Advanced Tunnelling’s tunnel reinforcement designs for Italy’s Autostrade.
Fast Metrics:
- Modelling and design time reduced by 25%
- Time to project deliverables improved by better than 20%
- Verification and interpretation of survey data accelerated by 30%
- Time taken to identify clash detection cut by 30%