Earthworks and Slope Stability


1-day course

CPD Credit: 7 hours, C1 / C2

Course Aim

This course will address earthworks and slope stability. Earthworks are a significant design and construction requirement for a wide range of engineering projects ranging from site developments for warehouse, pharmaceutical or industrial type units, to windfarms and major road or motorway schemes.

Course Overview

In this course we review the classification and acceptability of a range of engineering fill materials in accordance with the standard earthworks specification published by Transport Infrastructure Ireland (TII), which is widely used for civil projects in Ireland.  Guidelines are given for processing unacceptable materials into acceptable engineering fill. Specific consideration is given to risks related to Made Ground, and to pyrite in unbound granular fill materials.  Methods of ground improvement are presented for construction on Made Ground, and for processing unacceptable cohesive fill into high specification structural fill and capping by lime-cement stabilisation.

The second half of this course deals with slope stability in soil and rock.  The stability of rock slopes is discussed in terms of the different failure mechanisms that are related to the rock mass structure and discontinuity characteristics.  Guidance is given on the different methods of limit equilibrium analyses that are suitable for the assessment of slope stability in soil and highly weathered rock.  The significance of groundwater in relation to slope stability is discussed and illustrated by case studies of large slope failures.  Finally, the course specifically addresses the stability of embankments constructed on soft ground as well as methods for assessing the risk of peat instability for civil projects on upland blanket bogs.


The course is organised into four modules over the course of one day:

  1. Earthworks: Material Classification, Acceptability and Processing of Unacceptable Fill
  2. Earthworks: Made Ground, Pyrite and Ground Improvement
  3. Slope Stability: Soil and Rock Slopes – Methods of Assessment & Impact of Groundwater
  4. Slope Stability: Embankments on Soft Ground and Peat Stability

Learning Outcomes

  • An understanding of the classification of granular and cohesive fill materials in the TII Earthworks Specification.
  • Guidelines for assessing acceptability of cohesive and granular fill materials.
  • A description of methods of processing unacceptable materials into acceptable engineering fill.
  • An understanding of the geotechnical risks related to Made Ground, and to pyrite in unbound granular fill materials.
  • Familiarity with methods of ground improvement for construction on Made Ground and for processing unacceptable cohesive soils into structural fill and capping by lime-cement stabilisation.
  • Guidance on suitable methods of analysis for assessing the stability of slopes in soil and rock.
  • An appreciation of the significance of groundwater and seepage in relation to slope stability.
  • An understanding of specific geotechnical risk related to the stability of embankments on soft ground.
  • Best practice guidelines for the assessment of the stability of peat for civil and earthworks projects on upland blanket bogs.

Who Should Attend?

This course would be suitable for civil and geotechnical engineers, construction site-engineers and technicians working on civil, building and infrastructure projects, as well as engineering geologists and geologists interested in these topics.

Trainer’s Profile

Conor O’Donnell, BA, BAI, MS, FGS, CEng, MIEI, FConsEI, Managing Director of AGL Consulting

Conor O’Donnell is the Managing Director of AGL with 25 years’ experience as a Geotechnical Engineer in Ireland and the United States.  He has a Bachelors Degree in Civil, Structural and Environmental Engineering from Trinity College Dublin, and a Masters Degree in Geotechnical Engineering and Structural Mechanics from Cornell University, Ithaca, New York. 

Prior to 2001, Conor worked for Mueser Rutledge Consulting Engineers, a specialist geotechnical engineering consulting firm in New York City.  At MRCE, Conor specialised in the geotechnical design of foundations, excavation support systems and ground improvement schemes, including deep soil mixing, grouting and ground freezing.  He worked on a number of landmark tunneling and underground mass transit projects, including the NATM tunnel for the MBTA South Boston Transitway under Russia Wharf, and Contract C09A4 of the Boston Central Artery Project, which involved tunnel jacking under the railway lines at the approach to South Station in Boston, Massachusetts.

At AGL Conor has been involved in a number of major civil, infrastructure and commercial building projects across Ireland at planning, detailed design and construction stage with extensive experience of earthworks designs for road schemes.   He was lead geotechnical consultant for the preliminary and detailed ground investigation stages of the N4 Collooney to Castlebaldwin Road Scheme, and he has been the independent Category 3 checker on the earthworks design of over 250 km of motorways across Ireland involving a wide variety of specialised geotechnical constraints ranging from deep soft ground and karstified limestone, to variable glacial till and outwash deposits. He was also the lead geotechnical designer on the Lidl Regional Distribution Centre in Newbridge, Co. Kildare, which involved ground improvement of site-won stratified soft alluvial clay and gravel by mixing, blending and lime-cement stabilisation to form capping and structural fill below the main building and external concrete HGV concrete yards.  


  • Keith Goodwin, Kilsaran: “Very good course.”
  • Maciej Nowak, DBFL: “Very informative, excellent course content and brilliant delivery”
  • “Excellent and passionate presenter. Knows his stuff!”
  • “Excellent course”
  • “It was very informative, and I loved it”
  • “Very good material provided. Excellent guidance.”
  • “Interesting examples and projects work. Good content.”
  • “Conor was very informative and delivered the course material well”
  • “Very well organised and informative”
  • “Great course”
  • “Enjoyable, well-spaced and well conducted.”

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Engineers Ireland supports the Sustainable Development Goals. This event contributes to Engineers Ireland's Sustainability Framework.

Please contact the Team for further information on scheduled course dates and In-Company options. You can reach us by phone: 01 665 1305 or email