The WSP team is very proud to be part of the complex journey to rebuild the terminal, and is responsible for many different aspects of the project. We look forward to the outcome, where modern planning will allow public transport, pedestrians and cyclists to have more space and enjoy much-improved facilities.

At the beginning of 2019, we entered an intensive phase of the project, as the two-year task of blasting space for the new terminal in the rock underneath the Katarina Mountain began. Blasting in close proximity to a dense urban area requires highly sophisticated expertise in rock mechanics and structures; the experience and ability of our wider team has allowed us to take this on for our client, the City of Stockholm.

Slussen is a meeting point where underground, buses, commuter trains, boats, bikes, cars and pedestrians come together in a confined area. It is also a water gate connecting Lake Malar with the Baltic Sea. After 75 years of operation, Slussen has reached the end of its serviceable life and will be demolished and rebuilt from scratch. It will be converted into one of Stockholm's most attractive venues, with new squares, docks and the area's first park. Public transport will be allocated more space, as will pedestrians and cyclists, while surface car traffic will be reduced and adjusted to accommodate modern traffic planning requirements.

The new bus terminal is located in a rock cavern. The preliminary design was executed by WSP, based on the architectural design of Foster + Partners. Once completed, it will provide a secure and modern hub for commuters from the Eastern part of Stockholm. The bus terminal is being developed to seamlessly integrate with commuter train and underground services, allowing for smooth and comfortable interchanges between buses, trains and underground, without leaving the station.

This project presents a lot of challenges, including logistics in connection with construction work in the area, an extremely short time frame for design and construction, the complexity of the work, very high traffic volume, evacuation safety, consensus surrounding the location of the terminal, traffic safety inside the terminal, limited space for construction in order to maintain full traffic capacity, project planning with consultants and contractors in various areas, while also coordinating efforts with a separate client team and communicating with the public and local resident groups.

Massive amounts of rock will be excavated using blasting in this heavily urbanized area. This requires an extensive control program for measuring and controlling blast induced vibrations. The caverns are located in close proximity to existing underground structures such as a metro station, two parking garages and a public bomb shelter. This requires unconventional technical rock engineering solutions and advanced structural engineering. An access point will be created to the Metro station while the train traffic remains active at all times.

The terminal is also close to an existing rock slope, with many old houses being right outside of the zone affected by the blasting. These houses are marked as culturally valued objects that need to be preserved. For the rock excavation works, there will be many simultaneous ongoing tunnel faces, creating a logistically complex mass-haul/construction situation.

Another challenge is the massive amount of MEP needed in the terminal to handle crucial safety and comfort demands. The terminal is being used by buses fueled with natural gas, which creates huge demands for effective ventilation and gas detection systems, as well as creating a need for both the rock and structural elements to withstand extreme fire and explosion loads should an accident occur.

The detailed scope of WSP services includes permanent way, rock mechanics, structural engineering, road design, geotechnics, land development, surveying, cable ducting, light design, plumbing, geohydrology, risk analysis, telecommunications, project management, production planning, fire and safety, and water and sewerage.

Sub-consultants are being used for ventilation and architecture.

Using 3D BIM design models to reduce risk profile

WSP has mobilized an experienced multi-disciplinary team of engineers, architects, town, traffic and construction planners, cost managers and environmentalists, who have established a clear strategy that aims to reduce the risk profile to the scheme, while providing development and clarity to the delivery program.

Additionally, WSP’s extensive experience with BIM plays a crucial role in the project, where the detailed design is delivered almost completely in the form of BIM models. For example, there are no measured drawings, with 3D models being used instead, directly to the total stations. Reinforcement is delivered only as 3D models, and the workers use tablets to place the reinforcement.

The tender design phase is complete, and work on the detailed design began in late 2017, with two smaller parts already under construction. Construction of the terminal itself started in December 2018.

Our team is delivering the following services:

• Permanent Way
• Rock Mechanics
• Structural Engineering
• Road Design, Geotechnics
• Land Development
• Surveying
• Cable Ducting
• Light Design
• Plumbing
• Geohydrology
• Risk Analysis
• Telecommunications
• Project Management
• Production Planning
• Fire and Safety
• Water and Sewerage