Report on the International Geosynthetics Society UK Chapter student papers evening, held at Nottingham Trent University on 8 May 2002 .By Joanne Norris, research associate, Nottingham Trent University.
This student papers evening was a chance for young geotechnical engineers on PhD or MSc courses to compete for the International Geosynthetic Society prize of an all-expenses-paid trip to the 7th International Conference on Geosynthetics in Nice, France, 22-27 September 2002.
As in previous years, students who had prepared high quality assignments for the geosynthetics module of the MSc course in geotechnical engineering design and management at Nottingham Trent University were invited to present their topic to a joint meeting of the IGS and East Midlands Geotechnical Group. The applicant who delivered the best presentation would be invited to prepare a paper for the Nice conference.
IGS UK Chairman John Greenwood chaired the meeting and introduced three excellent presentations by Brian Nottage of Peter Brett Associates, Catriona Miller of NTU/Scott Wilson and David Reynolds of Keller Ground Engineering.
Nottage presented a case study on the use of geogrid to prevent sudden collapse of unstable ground caused by large voids.
A large subsurface void had appeared next to a primary school building in Northampton (Figure 1). Ground investigation revealed that the void was connected to a linear fissure feature which extended beneath the school.
After a comparison of remediation techniques, geogrid was chosen as the best as it could be installed in a relatively short time-scale.
Figure 2 shows placement of the geogrid.
Miller presented a case study of the use of geotextiles in a coastal protection scheme at East Weymss, Scotland (Figure 3) (Ground Engineering Oct 2001). The North Sea was eroding vast amounts of beach material at East Weymss, leaving the village vulnerable to flooding and storm events.
The coastal protection scheme used Geofabrics MP2000 geotextile incorporated with a rock armour revetment (Figure 4). The geotextile provided a free draining system between the revetment and the beach material and held the fine beach material in place under the rock revetment, preventing further erosion. The works cost £4.5M.
Reynolds presented a detailed cost comparison of using geosynthetics versus more traditional methods for remediation of cuttings and embankments on a hypothetical railway site in Oxfordshire.
His comparisons showed that if geosynthetics were used, costs would be reduced significantly.
Traditional drainage cost £60,000 Geosynthetics £25,000 Sheet pile wall cost £26,500 Geosynthetics £9,000 Gabion wall cost £320,000 Geosynthetics £83,200
The judges, Neil Dixon, Russell Jones and Ian Fraser of the International Geosynthetic Society committee and Ian Jefferson from the East Midlands Geotechnical Group, found it very difficult to decide between the three candidates.
The audience tried to assist with their votes but these were evenly spread among the candidates.
After careful deliberation, the judges announced that Catriona Miller would be invited to prepare her presentation as a paper, and, if found acceptable by the committee, she should attend the Nice conference.