On solid ground? Predicting high-speed railway track settlement using geophysical analysis.

Project Highlights:

  • Application of cutting-edge research at a new engineering test-facility
  • Use of state-of-the-art geophysical and geotechnical analysis systems
  • Development of a research programme with immediate engineering and economic implications for next-generation transport solutions.

Summary

High-speed trains induce a small level of permanent settlement within their supporting railway track and ground during passage (Yu, 2019). The settlement grows over time, but the degree of settlement varies along the track depending upon geographical changes in ground conditions. The variation in settlement along the track is the most important factor in determining the strategy for maintenance; when settlement limits are exceeded, the track must be closed to rail traffic and expensive reconstruction work must be undertaken.

The ability to predict differential settlement levels would be a major advantage for optimising the future planning of rail maintenance schedules. This would require relationships to be derived between settlement behaviour under a fast-moving cyclic load, and local soil properties – the latter of which can be obtained through geophysical testing. Solving this challenge would represent a major prize for the rail industry, yet it has received almost zero attention due to the complex and multidisciplinary nature of the problem. During this project, you will explore and develop geophysical approaches using novel seismic sensors (e.g. fibre optic data, wireless stations) that can provide both non-invasive and cost-effective pseudo-geotechnical survey data.

Aims and objectives

During this project, you will develop a geophysical testing methodology that can be used to predict future high speed railway track settlement levels. In doing so, you will target the following objectives:

  1. Derivation of correlations between geophysical test results and settlement behaviour.
  2. Optimisation of geophysical testing procedures for fast deployment in railway settings.
  3. Investigation of remedial measures to minimise the rate of track settlement.

Training

The student will work principally under the supervision of Dr Sjoerd de Ridder (School of Earth and Environment), an expert in seismic imaging and inversion. Co-supervisors include Dr David Connolly (Leeds School of Civil Engineering), an expert in railway infrastructure engineering and leader of civils/track research at the Institute for High Speed Rail and System Integration. Additional supervisors include Dr Adam Booth and Dr Phil Livermore, who are experts in near-field geophysical testing methods and geophysical inversion. The student will benefit from access, and the relevant training, to Leeds sector-leading supply of seismic survey equipment across SEE and iHSRSI.

The project provides specific training in:

  1. Using state-of-the-art seismic equipment for seismic imaging and inversion methods.
  2. Developing theory suitable to process and interpret new types of geophysical datasets.
  3. Integration of learning from synthetic and real-data observations to determine the reliability of engineering-relevant parameters.
  4. The use of cutting-edge laboratory test apparatus to simulate an engineering track settlement.

Research at Leeds

The PhD student will work with experts in this field of research and will be part of the Applied Geophysics research group of the Institute of Applied Geosciences (School of Earth and Environment) of the University of Leeds: The UK’s largest industry facing geoscience institute with application and impact towards energy, environmental, industrial and infrastructural problems. We have a diverse research base, strong international profile and are highly multi-disciplinary, with access to a recent (2019) state of the art high performance computing facility at Leeds. The PhD student will benefit from working within a supportive research group as well as from training at the university. The PhD student will be able to attend national and international conferences and workshops.

Applicant Profile

You will have a strong numeric background (e.g. geophysics, physics, computer sciences, engineering). You should have a passion for new geophysical theory and methods to push the boundaries of subsurface investigation to benefit the engineering sector and its environmental/economic implications. You will be expected to perform both physical laboratory testing and numerical simulation during the project. A competence with programming languages (e.g., Matlab, Python, etc) is also desirable. Finally, with the global reach of this research, you will be encouraged to present at international conferences.

References & Further Reading

BBC News (2019), Leeds & West Yorkshire, Leeds high speed rail research hub backed by government, https://www.bbc.co.uk/news/uk-england-leeds-48938252/, published 10 July 2019, (last accessed 1 November 2019).

Chang, J.P., S.A.L. de Ridder, B.L. Biondi (2016). High-frequency Rayleigh-wave tomography using traffic noise from Long Beach, CA., Geophysics, Vol. 81(2), pp. 1-11.

Connolly, D.P., G. Kouroussis, P.K. Woodward, P. Alves Costa, O. Verlinden, M.C. Forde (2014). Field testing and analysis of high speed rail vibrations, Soil Dynamics and Earthquake Engineering, Vol. 67, pp. 102-118.

Costa, P.A., P. Soares, A. Colaço, D. Connolly (submitted). Railway critical speed assessment: proposal of an-experimental-analytical approach; The in-situ experimental assessment of railway critical speed, to Soil Dynamics & Earthquake Engineering.

Gunn, D.A., J.E. Chambers, B.E. Dashwood, A. Lacinska, T. Dijkstra, S. Uhlemann, R. Swift, M. Kirkham, A. Milodowski, J. Wragg, S. Donohue (2018). Deterioration model and condition monitoring of aged railway embankment using non-invasive geophysics, Construction and Building Materials, Vol. 170, 2018, pp. 668-678.

Killingbeck, S. F., Livermore, P. W., Booth, A. D., & West, L. J. (2018). Multimodal layered transdimensional inversion of seismic dispersion curves with depth constraints. Geochemistry, Geophysics, Geosystems, 19(12), 4957-4971.

de Ridder, S.A.L., B.L. Biondi (2015). Near-Surface Scholte-Wave Velocities at Ekofisk from ShortNoise Recordings by Seismic Noise Gradiometry, Geophysical Research Letters, Vol. 42(17), pp. 7031-7038.

Ronda, A.J. (2016) Railway Formation Condition Assessment Using Seismic Surface Waves. MSc Thesis, University of Pretoria, South-Africa, p. 120.

Yu, Z., D.P. Connolly, P.K. Woodward, O. Laghrouche (2019). Settlement behaviour of hybrid asphalt-ballast railway tracks, Construction and Building Materials, Vol. 208, pp. 808-817.