The BGA's fourth annual conference will take place on 7 June at the Institution of Civil Engineers in London.
Its primary aims are to showcase some of the best and most interesting practice in UK and international geotechnical engineering and research and to inform members of developments in professional affairs, but most of all to give the UK geotechnical fraternity an opportunity to share views and experiences.
One of the highlights of the day will be the award of a prize to the winning individual or team for a settlement prediction competition (details below).
Entrants must be BGA members - to join, visit the BGA website: www. britishgeotech. org
BGA members are also invited to prepare A1 posters on current or recent engineering or research projects that will be on display throughout the day. There will be a fee for posters from commercial organisations.
Poster space is limited, so interested members should notify the BGA via email (below).
The conference is free but delegates should register in advance. A more detailed schedule for the day, together with a registration form and dinner booking form will be circulated with the May edition of Ground Engineering. Contact Janice Leung, tel: 020 7665 2233; email: bga@ice. org. uk
Prediction competition BGA members are asked to predict settlement for an embankment constructed on soft ground as described below.
For a recent road scheme in the UK, a 9m high embankment was constructed on soft ground.
The embankment led up to a grade separated junction (Figure 1). Monitoring was undertaken during the earthworks to compare predicted and actual settlements and porewater pressures to manage the earthworks process.
Ground conditions were:
2m thickness of peat, over
3m of soft alluvial clay and silt, over
1m of alluvial sand, underlain by
The peat was excavated and replaced with a granular starter layer with a basal geotextile reinforcement layer.
The contractor placed ll on the starter layer to a level of 1.5m above original ground level (OGL) as the first fill lift to bed in the starter layer and monitoring system.
Fill was placed from 1.5m up to a height of 4.2m above OGL as the second lift. The construction period for the placing of the rst and second lift was 77 days. The hold period duration after the second lift was 37 days, after which the settlement had more or less levelled out. The lling to nal road level (9m above OGL) was completed in a further two lifts.
Based on the CPT data in Figure 2, estimate the total settlement that occurred when the embankment was raised from 1.5m high to 9m high.
Estimate the settlement that occurred when the embankment was raised from 1.5m above OGL to 4.2m above OGL.
Please note the Figure 2 reproduced here is indicative - the data le can be found at www. britishgeotech. org. uk.
Send your answers to Janice Leung at the ICE, by email (janice.leung@ice. org. uk) or by post to One Great George Street, Westminster, London SW1P 3AA. All entries must arrive by Monday 24 May, 2006.