Binks Institute for Sustainability: Development of a rapid characterisation method for the engineering response of trees for hazard assessment and use in nature-based solutions

Climate Change is resulting in increasingly extreme weather events which can have significant impacts on transport infrastructure:

Heavy rainfall in upland areas can generate destructive debris flows (rapid movements of fluidised soil) cutting off critical transport corridors, with the most well-known example in Scotland being the A83 Rest and Be Thankful. Tree planting has been proposed as a nature-based solution that can reduce triggering of flows (through root stabilisation of soil) and reduce the impact of flows (acting as natural/bioengineered baffles).  

Extreme winds can result in windthrow of trees adjacent to overhead lines of rail infrastructure, causing loss of service and potentially fires; overhead lines will become significantly more prevalent as rail continues to electrify (Net-zero).  

Both these examples require the quantification of the push-over resistance of trees for engineering design/hazard assessment. This is difficult to do due to the natural variability of biological systems and the difficulty of conducting destructive tests on live trees.  

 The supervisory team have recently supervised an SRPe-funded UoD PhD project (student: Andrea Marsiglia) which has conducted preliminary tests of a low-cost dynamic monitoring system which can be used to record the response of trees under ambient wind vibrations to characterise the tree response implicitly including the biological variability. During this project, some initial field testing was conducted at the UoD Botanic Gardens. There remain a number of challenges before the method can be widely applied in practice, chiefly relating to the models for converting the low magnitude dynamic vibration response to the expected large displacement rapid monotonic response expected when subject to debris flows or extreme wind gusts (design case), and a need for further validation beyond the initial pilot scale of work to date.  

This project will utilise a new efficient modelling approach developed in a recent UoD PhD project for modelling slow tree-pulling tests (thesis of Dr Xingyu Zhang) and adapt this for dynamic and fast monotonic loading by incorporating velocity dependent elements to capture rate effects. The new model will be validated through physical model tests conducted on the UoD centrifuge facility, simulating dynamic vibrational and rapid monotonic loading using the centrifuge’s ground motion simulator in conjunction with an award-winning procedure developed by the principal supervisor. Once validated, the model will be used to generate a suitably large statistical dataset to fully explore and understand the mapping between ambient measurements and design conditions.  

Once validated, the method will then be applied to the field dataset collected in the recent work at UoD Botanic Gardens. This dataset will be significantly extended through further dynamic measurements at the Botanic Gardens (proposed project collaborator Kevin Frediani), using expertise from the James Hutton in field instrumentation and plant science (proposed collaborator Dr David Boldrin).  

For informal enquiries about the project, contact Professor Jonathan Knappett, School of Science and Engineering, j.a.knappett@dundee.ac.uk

For general enquiries about the University of Dundee, contact doctoralacademy@dundee.ac.uk

Our research community thrives on the diversity of students and staff which helps to make the University of Dundee a UK university of choice for postgraduate research. We welcome applications from all talented individuals and are committed to widening access to those who have the ability and potential to benefit from higher education.

QUALIFICATIONS

Applicants must have obtained, or expect to obtain, a UK honours degree at 2.1 or above (or equivalent for non-UK qualifications), and/or a Masters degree in a relevant discipline. For international qualifications, please see equivalent entry requirements here: www.dundee.ac.uk/study/international/country/.

English language requirement: IELTS (Academic) overall score must be at least 6.5 (with not less than 5.5 in reading, listening, speaking and 6.0 in writing). The University of Dundee accepts a variety of equivalent qualifications and alternative ways to demonstrate language proficiency; please see full details of the University’s English language requirements here: www.dundee.ac.uk/guides/english-language-requirements.

 

APPLICATION PROCESS

Step 1: Email Professor Jonathan Knappett, School of Science and Engineering, j.a.knappett@dundee.ac.ukto (1) send a copy of your CV and (2) discuss your potential application and any practicalities (e.g. suitable start date).

Step 2: After discussion with Professor Knappett, formal applications can be made via our direct application system. When applying, please follow the instructions below:

Candidates must apply for the Civil engineering research degrees University of Dundee, UK using our direct application system:

Please select the study mode (full-time/part-time) and start date agreed with the lead supervisor.

In the Research Proposal section, please:

–         Enter the lead supervisor’s name in the ‘proposed supervisor’ box

–         Enter the project title listed at the top of this page in the ‘proposed project title’ box

In the ‘personal statement’ section, please outline your suitability for the project selected.