In 2016, Burland was elected as a member of the National Academy of Engineering for contributions to geotechnical engineering and the design, construction, and preservation of civil infrastructure and heritage buildings.[2][3]
His MSc work led to the publication in of a landmark[4] technical paper in Géotechnique, co-authored with his supervising professor Jeremiah Jennings.[6][7] Burland's findings showed that the conventional approach of using effective stress to predict soil behaviour required adjustment for partly saturated conditions. The paper challenged the universality of the effective stress principle by demonstrating that its predictive accuracy diminishes under conditions of partial soil saturation, which led to a re-evaluation of some foundational concepts in soil mechanics.[8][9]
Burland returned to England in 1961 and took up a position with Ove Arup & Partners in London, where he provided soil mechanics expertise for the design of what was then London’s tallest building, BP’s Britannic House headquarters in Moorgate.[10]
In 1963, Burland commenced a PhD at the University of Cambridge under the supervision of professor Kenneth H. Roscoe. He published his thesis, Deformation of soft clay, in 1967.[11]
In 1980 he was appointed to the Chair of Soil Mechanics at Imperial College London, where he served for over 20 years and was Head of the Geotechnics Section. His move to Imperial gave him the chance to collaborate with Alec Skempton. Holding Skempton in high regard, Burland paid homage by christening Skempton’s former office with a sign that read “Skem’s Room” after he was given the room on Skempton’s retirement.[13][14] Burland also undertook lectures at several universities and institutions, including his alma mater, Witwatersrand.[4]
The Leaning Tower of Pisa Stabilisation Project, 1990 - 2001
After the collapse of the Civic Tower in Pavia in 1989, which killed four people, the stability of the tower at Pisa was widely questioned. In March 1990, Burland was asked by the Government of Italy to be part of a 14-member committee charged with stabilising the Leaning Tower of Pisa. With direct involvement in the project over 11 years, Burland made significant contributions to the work, which involved an innovative approach to counteract the tower's precarious lean. The project aimed to ensure the long-term stability of the historic structure without compromising its integrity.[31][32][33][34]
Burland and his team faced numerous challenges, including understanding the complex soil mechanics and historical construction techniques of the tower. The tower, resting on weak, highly compressible soils, has increasingly leaned over the centuries, reaching a state of leaning instability which by the late 20th century had threatened to cause a collapse. Burland concluded that any attempt to disturb or strengthen the ground on the south side, such as through underpinning or grouting, would be extremely hazardous due to the tower's precarious condition and the high stress on its masonry, risking collapse.[35]
In line with international conservation standards for valuable historic monuments, any interventions needed to minimally impact its integrity, preserving its history, and craftsmanship, with little to no visible changes. Burland's approach included both temporary and permanent stabilisation measures. Initially, temporary stabilisation was achieved by applying 900 tonnes of lead weights on the north side of the foundations, using a post-tensioned concrete ring. This method, and accurate prediction of tower behaviour using numerical models, was crucial in stabilising the tower while permanent solutions were developed. The permanent solution aimed to reduce the tower's inclination by about 10 per cent, a strategy expected to significantly prolong the tower's lifespan without invasive actions like propping or underpinning.[29]
The soil extraction process used in the Leaning Tower of Pisa project was a pivotal aspect of the stabilisation work. This technique involved the careful removal of soil from beneath the north side of the tower's foundations. This strategic extraction allowed for a controlled and gradual reduction of the tower's lean, reducing stress on the masonry and enhancing the structure's stability. Burland's implementation of this method was crucial in achieving the desired reduction in the tower's inclination without invasive structural interventions.[36]
Underground Car Park at the Houses of Parliament, 1972 - 1974
A proposal to construct an underground car park for Members of Parliament at Westminster had been considered for many years. New Palace Yard was eventually chosen despite the engineering challenges posed by the proximity of significant buildings. The project involved constructing an 18.5-metre-deep underground car park in close proximity to the historic Palace of Westminster, including Westminster Hall, the House of Commons, and the Big Ben Clock Tower.[37]
The design was heavily influenced by geotechnical considerations. Burland personally split and inspected London Clay soil samples from numerous boreholes at the site. London Clay is an ideal medium for deep excavations, as it has good shear strength and low permeability. However, it is susceptible to volumetric changes depending upon its moisture content.[38][39]
Burland's analysis revealed that thin partings of silt and sand within the structure of the London Clay at New Palace Yard were problematic, giving rise to the possibility of flow through the soil. Burland identified that pore water pressures in the clay were in hydrostatic equilibrium with the water table in the overlying gravel, and insisted on special measures to prevent the risk of a catastrophic hydraulic uplift of the excavation base during the construction.[40]
Finite-element analysis was conducted to understand the behaviour of the structure and surrounding ground, using soil parameters derived from full-scale measurements in the London area. Burland and his team supervised a comprehensive monitoring programme, observing the movement of nearby buildings, displacement of retaining walls, base heave, and the verticality of the Big Ben Clock Tower. Significant vertical and horizontal ground movements, extending more than three times the depth of the excavation, were recorded. The predicted and measured movements were compared, and their effects on surrounding buildings were analysed.[37]
A reinforced concretediaphragm wall, strutted by permanent concrete floors, was selected to minimise ground movement. Construction commenced in July 1972 and was completed in September 1974, with the main excavation occurring successfully under Burland's supervision, between April and November 1973.[37]
In addition to university teaching work and research, Burland has made several media appearances to explain soil mechanics to a broad audience.[52][20] He was guest speaker at the 2023 Terzaghi Day, held annually by the American Society of Civil Engineers Geo-Institute on the birthday of Karl von Terzaghi.[53]
^Bilotta, Emilio; Flora, Alessandro; Lirer, Stefania; Viggiani, Carlo; Associazione Geotecnica Italiana; International Society of Soil Mechanics and Geotechnical Engineering, eds. (2013). Geotechnics and heritage. Boca Raton London New York Leiden: CRC Press. ISBN978-1-138-00054-4.
^Burland, J. B.; Standing, J. R.; Jardine, F. M., eds. (2001). Building response to tunnelling - Case studies from construction of the jubilee line extension, London: Volume 1: Projects and methods. London: Thomas Telford. ISBN978-0-7277-3017-6.
^ abJohnston, G.; Burland, J. (2004), "Some Historic Examples of Underexcavation", Advances in geotechnical engineering: The Skempton conference, Conference Proceedings, Thomas Telford Publishing, pp. 1068–1079, doi:10.1680/aigev2.32644.0033 (inactive 1 November 2024), retrieved 16 December 2023{{citation}}: CS1 maint: DOI inactive as of November 2024 (link)
^Burland, J.B.; Jamiolkowski, M.B.; Squeglia, N.; Viggiani, C. (21 August 2020), "The Leaning Tower of Pisa", The Tower of Pisa, First edition. | Boca Raton, FL : CRC Press/Taylor & Francis Group, [2020] | Series: Built heritage and geotechnics, 2640-026X ; 3: CRC Press, pp. 3–5, doi:10.1201/9781003046127-2, retrieved 16 December 2023{{citation}}: CS1 maint: location (link)
^ abcBurland, J.B.; Hancock, R.J.R. (1977). "Underground car park at the House of Commons, London: Geotechnical aspects". The Structural Engineer. 55 (2): 87–100.
^Graham, J.; Tanaka, N.; Crilly, T.; Alfaro, M. (2001). "Modified Cam-Clay modelling of temperature effects in clays". Canadian Geotechnical Journal. 38 (3): 608. doi:10.1139/cgj-38-3-608.