Ground investigation in Co. Monaghan

We recently commissioned a ground investigation in Co. Monaghan to support the design of a sports field. There is a deep cut into a slope at one end of the sports field, and using information from the recently-updated Geological Survey of Ireland (GSI) Quaternary Data Viewer we could begin to develop an understanding of the likely geology at desk study stage and make an informed prediction that overburden would extend to a significant depth.  The prediction was correct in this case and drilling encountered overburden of glacial till to the planned investigation depth.

Monaghan ground investigation

The latest GSI Quaternary mapping suggests the site is a drumlinised ribbed moraine. Current knowledge suggests that, in the region of interest, the transition from ribbed moraine (yellow areas in the image below) to drumlin bedform (magenta lines) may be related to ice movement increasing in velocity at this location during deposition. A lot of what we can say about the glacial landscape left behind in warmer places is informed by observations of current glacier movements in colder places, and the paper by Johnson et al. on observations of an active drumlin field in Iceland is a fascinating read on the topic. As with any project which involves an element of ground risk, an understanding of both the geological background of the site and the geotechnical properties of the materials there today is essential to achieving a reliable design.

Screenshot of GSI data plotted in QGIS

Soil nailed slope at Monktown, Co. Cork

It’s always great to see one of our designs put into practice. The photos in this post show a slope rehabilitation project recently completed using soil nail reinforcement techniques in Monkstown, Co. Cork. The slope was designed in accordance with BS 8006-2:2011 (Code of practice for strengthened/reinforced soils. Part 2: Soil nail design) and was constructed using Ischebeck Titan hollow bars and PVC-coated hexagonal steel wire mesh. Sacrificial and production soil nail testing was carried out to confirm the design assumptions made. A particular challenge for the contractor was the management of traffic on the busy single carriageway road at the toe of the slope. Zero tail swing plant were employed to great effect and the practicality of the project would have been very different without the utilisation of modern zero tail swing excavators and MEWPs. The slope is slowly beginning to green up and will blend into the landscape in due course.

32nd meeting of CEN TC250/SC7 in Oslo

We were delighted to attend the 32nd meeting of CEN TC250/SC7 (the committee responsible for Eurocode 7)  in Oslo on 22nd and 23rd May to discuss the direction of development of the 2nd generation of Eurocode 7, the harmonised standard for geotechnical design throughout Europe and further afield.

The aims of development are the simplification of the basis of geotechnical design, the reduction in Nationally Determined Parameters (NDPs) and the improvement of the accessibility and ease of use of the document. Significant changes are likely coming in the revised standard due after 2020, including replacement of the current Design Approaches with a simpler scheme, broadening the range of designs covered in detail to include reinforced soil and soil nailing, and changes in layout to make the new standard easier to navigate.

 

Ciaran Reilly & Associates helps #maplesotho

We were delighted to assist the students from Portmarnock Community School and Action Ireland Trust with validation during a hectic and fun 24 hour mapathon that took place on 5th and 6th May. The mapathon was part of the school’s ongoing commitment to improving civic life in the mountain kingdom of Lesotho. While the school, with Fingal County Council’s technical assistance, has been working since 2014 to create an open, free basemap of the Kingdom, the aim this time was to improve the tagging of buildings and farm land to assist in spatial planning. The Humanitarian Openstreetmap Team tasking manager recorded that over 300,000 edits had been made by Portmarnock CS mappers in the 24 hours, which was certainly a significant achievement!

MapLesotho Mapathon May 2017

More information, and information on getting involved, is available from the #MapLesotho projectAction Ireland Trust, and the award-winning Global Citizens Mapping the Future initiative within Portmarnock CS.