The construction site of the 33-storey student accommodation building at Miles Street, London was too tight to fit a piling rig, thus the engineering team adopted an alternative piled raft foundation solution for the building's support.
The Urbanest Student Accommodation building is being constructed with a slip formed core, on a small site, with a quite tight construction timeline. The challenges concerning its foundation had to do with the combination of a restricted 1000 m2 triangular site next to a Network Rail viaduct and several existing buildings (meaning sensitive settlement requirements), as well as a deadline to start work, meaning that a pile load test to reduce the design factor of safety was not possible. Without such a test, Balfour Beatty - contractor of the project - could only use piles of 1200mm diameter in order to achieve the loads. However, the necessary piling rig would have been too big for the site.
In cooperation with geotechnical consultant CGL, structural engineer Walsh Associates proposed an innovative piled raft foundation as a solution to the problem. They designed a lean concrete frame to reduce the foundation loads, supporting it with a piled raft, using high and deep level ground support capacities to limit deflections.
What is more, along with the design of a slip formed core for the building, drainage was also placed on top to shorten the required design time, allowing the construction of the foundation before the drainage scheme was fixed, while water attenuation pipes were used instead of the typical attenuation tanks.
The £42m project started in July 2016 and is due to finish at the end of 2017.
Source: The Construction Index
Language: English Registration: Free Pile groups and piled rafts are challenging design problems...
Pile groups and piled rafts are challenging design problems in the sense that they are 3D...
FEM Modelling: Piled Raft Foundation Analysis in 2D and 3D A common use for deep foundation piles...
Foundation is the lowest part of a structure which transfers loads from the superstructure to the...
Modern infrastructural design and architecture are evolving due to rapid improvements in modern tec...
A deep foundation is a type of foundation which is placed at a greater depth below the ground surf...
Even if a foundation structure meets all the strength requirements, it should also satisfy another c...
Shallow foundations, often called footings, are situated beneath the lowest part of the structure...
The iconic 58-storey residential building known as Millennium Tower at the city of San Francisco co...