First update on Upper Orwell Crossings ground investigation works published


Suffolk County Council has published the first update on the Upper Orwell Crossings ground investigations on Tuesday 13 February 2018.

A progress report (PDF, 16KB) details the works undertaken by Fugro Geoservices Ltd, who will be spending around three months investigating the geology. These investigations help finalise the design of the three bridges.

Tests onshore have taken place in a number of locations along the River Orwell and have confirmed the area has significant depths of underlying chalk, some of which is softer than expected. This information is valuable to know at this stage in the design process as it will affect the type and depth of foundations for the bridge and approach embankments.

Offshore investigations have also been taking place too. Once the two jack-up barges were adapted for the project work, the vessels were floated into position along the eastern bank of the port area where boreholes were drilled to 80 metres below ground level for testing and analysis on the marine ground conditions.

Following this, the barges were moved to borehole locations on the western bank for further testing, from here they have been moving east across the river stopping at numerous locations. At the moment the barges are located adjacent to the navigation channel, where another series of complex testing is scheduled to take place.

Looking ahead, offshore work is to begin along the New Cut next week. Land-based works will continue, with some works on the highway planned for March 12. These works will take four days and will take place outside of morning and evening rush hours to reduce disruption.

Jack-up barges testing the marine ground conditionsAerial footage of the jack-up barges testing the marine ground conditions.

Ground investigation works on riverThe ground investigation works began on 15 January and could take up to three months to complete.

Building materials in storageThese investigations will help finalise the design of the three bridges.