Tetra Tech was contracted by Maccaferri Construction Limited to undertake the design work for the load transfer platforms and reinforced soil walls for the new, elevated railway at Reading Station on behalf of Balfour Beatty Civil Engineering for Network Rail. This elevated railway aims to relieve congestion by separating the existing main lines from the freight lines at the Westbury Line Junction and the Reading West Chord Junctions to create a grade-separated junction. 

Tetra Tech was selected to design an efficient system that was capable of absorbing the high accidental loading case caused by derailing trains. This type of reinforced soil retaining wall to carry railway loadings in the United Kingdom is unusual. Horizontal loads, high vertical strip loads towards the front of the wall, and limited surcharge over the top reinforcing straps created a complex design problem for the team.

Our team addressed the problems by creating a unique piece of design software to tackle the specific project difficulties. The software was designed to analyze both loads and resulting reinforcement requirements, using the Maccaferri-manufactured MacRes reinforced soil system. The software, which is based in Microsoft Excel, is scalable and has been adapted to use in other projects.   

Tetra Tech provided a design that was constructed solely of Maccaferri products. The elevated railway was constructed on reinforced soil retaining walls that tie into new viaducts over the freight lines. Ground improvement, in the form of vibro-concrete columns (VCC), was required and coupled with a load transfer platform to support the new embankments. 

Throughout the project, our team ensured that all members of the design team were coordinating on all aspects of the project. Tetra Tech offered extensive advice to the other consultants responsible for design of the VCC, external stability of the wall, and robust kerb detailing at the top of the wall. This close coordination ensured that the structure as a whole was satisfactory.

One of our client’s major risks was if the design program ran behind schedule, resulting in the facing panels not being able to be manufactured in time. We worked closely with Maccaferri throughout the design process to ensure strict timelines were met. 

The design of both the load transfer platform and reinforced soil retaining walls was completed to a high standard, and Tetra Tech had an active role in ensuring effective design coordination amongst the design team. The resulting design was both easy to construct and efficient, making the best use of the Maccaferri systems.