At 84 storeys, with a 15m deep basement, the Shard at London Bridge Station is the tallest building in Europe to date. It is constructed within one metre of the historic brick vaults that support the station and within eight metres of live rail lines. On behalf of Network Rail, our engineers have been assessing the reaction of existing structures to the building’s construction and advising on necessary measures to protect its assets during the construction period.
London Bridge is the fifth busiest station in Europe, and one of the oldest, with construction primarily taking place in the 1830s and 40s. Its tracks and concourse are supported on a range of brick arches and an elegant train shed roof spans the platforms. We assessed the likely ground movements resulting from deep excavations immediately adjacent to station structures and the permanent way. As construction progresses, we are also carrying out essential monitoring of ongoing movement.
The combined effect of the movements is being assessed over time and analysed in conjunction with the built form of the station in order to predict likely damage to the structures and interference with the rail lines. Appropriate monitoring, base condition surveys and emergency procedure plans were agreed to confirm the initial positions and then to track the changes as work proceeds. Assessment results are discussed with the Shard's design team so that necessary mitigation measures can be undertaken.
We developed a 3D computer model of the massive masonry structure in order to predict and assess the influence of ground movement. Creating it involved 3D laser scanning, surface modeling, solid modeling and the assembly of a massive finite element model. This cutting-edge process resulted in a structural model that, at 13,500,000 degrees of freedom, is probably the largest numerical model so far produced in the UK construction sector.