Unsaturated Soils Mechanics for Engineering Practice (UnsatPractice)
Lead Research Organisation:
Durham University
Department Name: Engineering
Abstract
This partnership programme involves collaboration between Durham University UK and five universities in South Africa (the University of Pretoria, the Central University of Technology, Free State, the University of Kwazulu Natal, the University of Cape Town and Stellenbosch University) on a project entitled "Unsaturated Soils Mechanics for Engineering Practice (UnsatPractice)". The unsaturated characteristics of soils give rise to many geotechnical problems in the UK and in South Africa including collapse of foundations due to inadequate bearing capacity, structural damage due to excessive ground heave, sinkhole formation, slope instability both in terms of natural slopes and man-made embankments, as well as road and railway formation failure. The network comprises 13 academic staff and will train 20 PhD students. The research activities within the network are divided into three strands: laboratory and in-situ testing of unsaturated soils, development of numerical models and applications to engineering problems. The network partners will generate significant follow-on projects by seeking new research funding from national and international research councils and agencies and will establishing formal long-term sandwich PhD programmes before the end the award period.
Planned Impact
Expansive and collapsible soils are particularly sensitive to soil moisture changes. As the water content of an expansive soil increases during the wet season, the soil swells causing surface heave. During the dry season, shrinkage occurs producing settlements. Collapsible soils are characterised by large inter-particle voids, supported either by suctions in the pore-water, by cemented bonds between particles or by clay "bridges" between particles (that are themselves supported by suctions). If the soil is wetted, the suctions reduce and/or the cementing is dissolved or removed and the soil "collapses" causing a sudden reduction in volume resulting in surface settlements. This seasonal shrink/swell cycle can cause significant damage to buildings directly founded on these soils. This seasonal shrink/swell cycle can cause significant damage to buildings directly founded on these soils. The costs of damage due to shrink/swell movements on clay soils have resulted in economic losses estimated at over £1.6 billion in the UK during drought years in the 1990s. Similar figures are evident from France where losses have been as high as £2.7 billion in a single year. In China, losses due to land subsidence in Shanghai are estimated to be about £10 billion over a decade with £0.3 billion a year in losses in three other cities. Of relevance to this proposal is the fact that collapsible soils cover 67% of the total area of South Africa and their presence has an impact on most infrastructure development.
The network will enhance the ability of the partners to respond to the needs of both the domestic and international construction industry to evaluate optimal foundation and pavement designs in unsaturated soils. Therefore, the combined research will reduce potential damage to properties and infrastructures. The network will enhance significantly the mobility and international visibility of each of the partners involved. It will also provide a legacy of well-trained UK and South African experts equipped to solve the engineering challenges of infrastructures in unsaturated soils.
The network will enhance the ability of the partners to respond to the needs of both the domestic and international construction industry to evaluate optimal foundation and pavement designs in unsaturated soils. Therefore, the combined research will reduce potential damage to properties and infrastructures. The network will enhance significantly the mobility and international visibility of each of the partners involved. It will also provide a legacy of well-trained UK and South African experts equipped to solve the engineering challenges of infrastructures in unsaturated soils.
Publications
OSMAN A. S.,
(2019)
Numerical analysis of cavity propagation in deep trapdoor experiments
GASPAR, T.A.V.,
(2019)
Measurement of the soil water retention curve: practical considerations.
Osman A
(2019)
Analysis of maximum arching conditions in active plane-strain trapdoors in sand
in Computers and Geotechnics
Al-Ghosoun A.
(2020)
A hybrid finite volume/finite element method for shallow water waves by static deformation on seabeds
in Engineering Computations
Al-Ghosoun A
(2020)
A hybrid finite volume/finite element method for shallow water waves by static deformation on seabeds
in Engineering Computations
Gaspar T.A.V.
(2022)
Investigating the design of piled foundations for wind turbines in swelling clays.
Gaspar T
(2022)
The mechanical properties of a high plasticity expansive clay
in Engineering Geology
Description | Research carried out during this project leads to a greater understanding of sinkhole collapse in South Africa. It also helps in understanding the performance of unsaturated soils in South Africa. It trained many young researchers on advanced numerical and analytical techniques |
Exploitation Route | This collaboration leads to further funding. The investigators have recieved a £1.27M GCRF/EPSRC grant (EP/P029434/1) to study foundations of wind turbines in African expansive soils. Several recommendations from this project have been adopted by industry. |
Sectors | Construction Education |
Description | The UnsatPractice programme established collaborations between Durham University (UK), a world leader in unsaturated soil mechanics and five universities in South Africa. One of the tangetinal impact of this program is the establishement of research programme in unsaturated soil mechanics at the University of Pretoria and increase the awareness of the practing geotechnical engineers in South Africa on the importance of applying unsaturated soil mechanics concepts. The UnsatPractice programme led to a greater understanding of unsaturated soils and will deliver reliable engineering design tools to satisfy performance criteria of foundations and infrastructure throughout operational lives. The UnsatPractice research aimed to develop a risk mitigation strategy for structures on expansive and collapsible soils. This strategy will have direct impact on the poorest people in the country as it can reduce damage to their properties. For example research on the development of sinkhole collapse in unsaturated soils is a key topic in this network and a key research activity in both Durham University and the South African partners universities. A one-day workshop was held on 8 Dec 2016 in Pretoria, attended by academics from the University of Pretoria, engineers and engineering geologists from industry which included representatives from the Cities of Tshwane and Ekurhuleni and the South African National Department of Public works. The workshop comprised a number of technical presentations featuring recent work about development on sinkhole in which the leak from water services is the triggering mechanisms. A number of deficiencies regarding the enforcement of legislation governing the development and abstraction of water were identified. Some of these are associated with poor performance of regulators. The recommendations were adopted by the Engineering Council of South Africa and the Minister of Public Work was informed of the dangers if the required standards are not enforced. The programme trained 7 PhD students from South Africa and equipped them with necessary skills to train the next generation of engineers in South Africa. All of them has completed successfully their PhD with four of them is now working as academics at South African universities and one of them got a lectureship position at a UK university. This partnership has created an excellent platform for cross-fertilisation and new long term synergies between network partners. One of the clear benefits is to facilitate substantially network-wide collaborations, sharing and allowing access to the research and training facilities as well as research outputs. This partnership has established excellent opportunities for new collaboration between Durham University and partner universities in South Africa in a very short time. This partnership has attracted about £2.4M additional funding from EPSRC through two successful GCRF grant proposals: 1- £1,270,180 from EP/P029434/1: Developing performance-based design for foundation systems of WIND turbines in AFRICA (WindAfrica), 2- £1,108,696 from EP/P029671/1: Sustainability and Resilience of Transportation Infrastructure in African Countries |
Sector | Construction,Education,Transport |
Impact Types | Societal |
Description | Training for researchers and practitioners in South Africa on computational tools in geotechnical engineering |
Geographic Reach | Africa |
Policy Influence Type | Influenced training of practitioners or researchers |
Description | Using unsaturated soil mechanics framework to predict sinkhole collapse |
Geographic Reach | Africa |
Policy Influence Type | Implementation circular/rapid advice/letter to e.g. Ministry of Health |
Impact | A one-day workshop was held on 8 December 2016 in Pretoria, South Africa, attended by academics from the University of Pretoria, engineers and engineering geologists from industry active on development on dolomite land which included representatives from the Cities of Tshwane and Ekurhuleni and the SA National Department of Public works. The workshop comprised a number of technical presentations featuring recent work about development on dolomite land. A number of deficiencies regarding the enforcement of legislation governing development of, and abstraction of water from dolomite land were identified. Some of these are associated with poor performance of regulators. The group drafted a letter to the Minister of Public Work in South Africa to inform of the dangers if the required standards are not enforced. |
Description | Developing a risk mitigation strategy for sinkhole collapse in South Africa |
Amount | £5,000 (GBP) |
Organisation | Durham University |
Department | Durham University ESRC Impact Acceleration Account |
Sector | Academic/University |
Country | United Kingdom |
Start | 08/2016 |
End | 12/2016 |
Description | GCRF |
Amount | £1,270,180 (GBP) |
Funding ID | EP/P029434/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 04/2017 |
End | 05/2020 |
Description | Sustainability and Resilience of Transportation Infrastructure in African Countries |
Amount | £1,108,696 (GBP) |
Funding ID | EP/P029671/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 04/2017 |
End | 10/2020 |
Description | Cultural, Educational and Scientific Collaboration |
Organisation | Central University of Technology, Free State |
Country | South Africa |
Sector | Academic/University |
PI Contribution | We have managed to convenience the senior management in Durham and partner universities to sign a collaboration agreement. |
Collaborator Contribution | This agreement facilitates the future collaboration between partner universities and Durham University. Partners universities have waived bench fees for visiting academic from Durham. They facilitate the managements of the training events delivered by researchers from Durham. |
Impact | This agreement facilitates the exchange of researchers and academic staff in Science faculties in the partners' universities. The bench fees were waived for visiting academics. |
Start Year | 2016 |
Description | Cultural, Educational and Scientific Collaboration |
Organisation | University of Cape Town |
Country | South Africa |
Sector | Academic/University |
PI Contribution | We have managed to convenience the senior management in Durham and partner universities to sign a collaboration agreement. |
Collaborator Contribution | This agreement facilitates the future collaboration between partner universities and Durham University. Partners universities have waived bench fees for visiting academic from Durham. They facilitate the managements of the training events delivered by researchers from Durham. |
Impact | This agreement facilitates the exchange of researchers and academic staff in Science faculties in the partners' universities. The bench fees were waived for visiting academics. |
Start Year | 2016 |
Description | Cultural, Educational and Scientific Collaboration |
Organisation | University of Johannesburg |
Country | South Africa |
Sector | Academic/University |
PI Contribution | We have managed to convenience the senior management in Durham and partner universities to sign a collaboration agreement. |
Collaborator Contribution | This agreement facilitates the future collaboration between partner universities and Durham University. Partners universities have waived bench fees for visiting academic from Durham. They facilitate the managements of the training events delivered by researchers from Durham. |
Impact | This agreement facilitates the exchange of researchers and academic staff in Science faculties in the partners' universities. The bench fees were waived for visiting academics. |
Start Year | 2016 |
Description | Cultural, Educational and Scientific Collaboration |
Organisation | University of Pretoria |
Country | South Africa |
Sector | Academic/University |
PI Contribution | We have managed to convenience the senior management in Durham and partner universities to sign a collaboration agreement. |
Collaborator Contribution | This agreement facilitates the future collaboration between partner universities and Durham University. Partners universities have waived bench fees for visiting academic from Durham. They facilitate the managements of the training events delivered by researchers from Durham. |
Impact | This agreement facilitates the exchange of researchers and academic staff in Science faculties in the partners' universities. The bench fees were waived for visiting academics. |
Start Year | 2016 |
Description | Cultural, Educational and Scientific Collaboration |
Organisation | University of Stellenbosch |
Country | South Africa |
Sector | Academic/University |
PI Contribution | We have managed to convenience the senior management in Durham and partner universities to sign a collaboration agreement. |
Collaborator Contribution | This agreement facilitates the future collaboration between partner universities and Durham University. Partners universities have waived bench fees for visiting academic from Durham. They facilitate the managements of the training events delivered by researchers from Durham. |
Impact | This agreement facilitates the exchange of researchers and academic staff in Science faculties in the partners' universities. The bench fees were waived for visiting academics. |
Start Year | 2016 |
Description | A short course on GIS for flood defenses |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | A two-day short course on GIS for flood defences had been organised on 28-29 Sept 2017 at the University of Pretoria. The course had been delivered by Dr Mohammed Seaid of Durham University. It was attended by 20 students and young engineers. The course delivers training on advanced GIS techniques. Very positive feedback is received. |
Year(s) Of Engagement Activity | 2017 |
Description | A short course on modelling groundwater flows |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | A two-day course on "Modelling groundwater flow" has been organised and delivered by Dr Mohammed Seaid on 26-27 Sept 2017 at the University of Pretoria. 20 postgraduate students and engineering graduates had attended the course. The course had introduced up-to-date research in the field. It raised the profile of the PhD exchange program and had received free good feedback from the attendees. |
Year(s) Of Engagement Activity | 2017 |
Description | A training course on "Modelling heat flow in complex geometries " |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | This course is delivered by Dr Mohammed Seaid of Durham University at the University of Pretoria. It was attended by 15 young researchers. The course sparked discussion and questions afterwards. The course draw interest in the subject as several audiences has contacted the speaker asking for more guidance and materials |
Year(s) Of Engagement Activity | 2020 |
Description | Discussion Forum: Thinking about hazards: a cross-disciplinary discussion |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Postgraduate students |
Results and Impact | A discussion forum on "Thinking about Hazards" held in Durham on 10 March 2016. This forum is organised in liaison with the Durham Universiy Institute of Hazard, Risk and Resilience. PhD students from Durham presented their work on unsaturated soil mechanics. PhD students and researchers in South African partners universities have also participated in the forum via WebEx (video conference system).This forum offered excellent opportunities for knowledge transfer and engagement across the network as they were reflected in the thorough discussion followed the presentations. |
Year(s) Of Engagement Activity | 2016 |
URL | https://www.dur.ac.uk/ihrr/news/pastevents/?eventno=29369 |
Description | Mitigation strategy against sinkhole collapse risks |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | A one-day workshop was held on 8 Dec 2016, attended by academics from the University of Pretoria, engineers and engineering geologists from industry active on development on dolomite land which included representatives from the Cities of Tshwane and Ekurhuleni and the SA National Department of Public works. The workshop comprised a number of technical presentations featuring recent work about development on dolomite land. A number of deficiencies regarding the enforcement of legislation governing the development and abstraction of water from dolomite land were identified. Some of these are associated with poor performance of regulators. It was a decision that the group will draft a letter to the Engineering Council of South Africa to a request to inform the Minister of Public Work of the dangers if the required standards are not enforced. |
Year(s) Of Engagement Activity | 2016 |
URL | https://www.dur.ac.uk/esrciaa/gcrf/sinkhole/ |
Description | PhD conference |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | We have organised a PhD session for the exchange students in this project in conjunction with the 17 African conference on Soil Mechanics and Geotechnical Engineering in Cape Town in October 2019 in order to maximise the impact. This conference is well attended by researchers and practitioners from different African countries. The work resulted from this grant is presented to the audience of about 200 delegates. It sparks debates and interaction from the audience. |
Year(s) Of Engagement Activity | 2019 |
URL | https://www.issmge.org/events/17th-arcsmge-conference |
Description | Short course on numerical analysis of unsaturated soil |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | A three-day course on GIS and coupled hydro-mechanical methods were delivered by Dr Mohammed Seaid at the University of Pretoria. The course was attended by 26 persons which included graduates students and staff from the University of Pretoria and a number of engineers from industry. |
Year(s) Of Engagement Activity | 2016 |
Description | Training course on "Numerical analysis in geotechnical engineering" |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | This course is delivered by Professor Charles Augarde of Durham University at the University of Pretoria. In this course, latest developments numerical methods have been presented. 35 young researchers and practising engineers have attended the workshop. The course sparked discussion and questions afterwards. The course draw interest in the subject as several audiences has contacted the speaker asking for more guidance and materials |
Year(s) Of Engagement Activity | 2019 |
Description | Training course on ground improvement delivered by Dr Paul Hughes |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | In this course, the latest techniques in ground improvement have been presented. 40 young researchers and practising engineers have attended the workshop. The course sparked discussion and questions afterwards. The course draw interest in the subject as several audiences has contacted the speaker asking for more guidance and materials |
Year(s) Of Engagement Activity | 2019 |
Description | Workshop on unsaturated soil mechanics research in South Africa |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Postgraduate students |
Results and Impact | A Videoconference via WebEx where 7 South African researchers presented their work on unsaturated soils to Durham researchers. It was organised on 23 June. The workshop sparks questions on the engineering practice in South Africa |
Year(s) Of Engagement Activity | 2016 |