London’s 150-year-old sewage system was built for a population of less than half of the city’s current 8 million people. As the outgoing waste exceeded capacity, millions of tons of untreated raw sewage flowed into the river each year. The Costain, VINCI Construction Grands Projets and Bachy Soletanche (CVB JV) joint venture is responsible for the design, construction and replacement of the eastern section of the £850 million tunnel, including 10 km of tunnel works located 70m below central London, as well as six well sites.

The project involves 12 design disciplines and numerous companies and supply chain stakeholders, all of whom had to avoid damage and disruption to historic buildings and neighboring neighborhoods under strict schedule constraints. CVB JV needed integrated digital technology to push the boundaries of conventional construction to deliver this super sewer system.

Overcoming Challenges with Construction Modeling

CVB JV established a connected data environment and implemented 4D construction modeling and collaborative planning to overcome project challenges and streamline construction engineering and management. The team built 3D models and linked them to the building program, creating over 30 intelligent 4D models. CVB JV used a common platform for the coordinated and multidisciplinary modeling and storage of all construction information. Bentley’s integrated technology provided a digital solution that established a visual sequence demonstrating the development of construction activities.

Prevent conflicts and manage subcontractors

SYNCHRO 4D facilitated 4D modeling for collaborative planning and digital construction management enabling efficient, safe and sustainable construction works. OpenBuildings Designer interoperability provided the 3D authoring capability to integrate supply chain models in different file formats into coordinated models on the ProjectWise platform. The use of SYNCHRO 4D allowed site crews to easily access, view and interrogate models to analyze and ensure optimal constructability of complex construction works. Bentley’s 4D digital technology solution resolved potential conflicts and effectively managed concurrent jobs among multiple contractors working together on highly congested sites.
“[Bentley’s] technology shortened design time, reduced resource hours, made meetings more productive, and eliminated tedious tasks. The collaborative approach achieved with SYNCHRO 4D was key in involving the client, designers and manufacturers in early decision making,” said Sandra Reis, BIM Manager, CVB JV.

Restoring the water quality of the Thames

Bentley’s solutions enabled the team to come up with a design that mitigates pollution and accounts for anticipated population growth. By using the 4D construction models in weekly collaborative planning meetings, CVB JV facilitated the development and planning of complex construction activities in advance, which saved considerable time on the project. 4D construction models improved site analysis, improved constructability, avoided damage to existing buildings and eliminated rework to save over 90 days in the construction program, equivalent to £300,000 in savings direct and GBP 1 million in indirect savings. Using Bentley’s collaborative digital applications, the project team provided accurate visualization of the construction process, improving both communication and understanding between site workers and stakeholders to streamline work flow processes. work, decision-making and approval. When completed in 2025, water quality in the Thames is expected to return to levels not seen since the construction of the original sewer system.

This article was written by Marion Bouillin, Product Marketing Manager, Construction, Bentley systems.