The Shard, London, UK: response of arches to ground movements

The Shard is a 310 m high mixed-use tower, built next to the masonry arches that support London Bridge railway station in central London. Ground movements have occurred because of the demolition of the 26 storey tower that previously occupied the site, the excavation of a three storey basement, and the construction of the new building. These ground movements have led to axial and rotational strains in the masonry arches. Enabling works for the Shard in the vicinity have also caused arch movements. Initial assessments of the effects of movement on the arches, including the likelihood of cracking, were carried out using charts published by Boscardin and Cording. However the arches at London Bridge consistently performed better than predicted. This paper presents the results from the Shard project, and discusses possible reasons for the difference from Boscardin and Cording's findings.