THE PROBLEM
Old, existing river training walls were incapable of supporting a newly proposed access road and footbridge to the new Burnley campus of the University of Central Lancashire.
THE SOLUTION
A Tensartech TW1 system was chosen to create a series of retaining walls to support the access road and to act as an abutment for a new footbridge along the River Calder, along with a series of walls around the entrance to the new university building, where level differences were encountered. As part of Tensar International’s Design and Supply service, detailed calculations were produced along with construction drawings and a fully indemnified design.
PROJECT DESCRIPTION
In 2007 a £70 million new campus for the University of Central Lancashire was given the go ahead in Burnley. The location chosen for the new campus was a Brownfield site in an old industrial part of the town, and it was bordered along the North Eastern edge by the river Calder. The existing river training walls were at the end of their structural life and needed to be replaced for the new development. Several options were explored for the replacement walls and abutment, including reinforced concrete and gabions. The Tensartech TW1 system was chosen by Shepherd Construction, and their Consulting Engineer, White Young Green, as a value engineered alternative that provided a low environmental impact. The required aesthetic finish complemented the surrounding buildings and provided a more sustainable procurement process.
The walls, which were founded on cohesive soils, were constructed using granular fill reinforced with layers of Tensar uniaxial geogrids which were secured to the TW1 block face with full strength polymer key connectors. The system has full British Board of Agrément approval and was designed by Tensar International for a 120 year life. The facing blocks which have an attractive split face finish were manufactured in Yorkstone colour to match the existing local buildings and other Tensartech retaining walls along the River Calder in Burnley. At its maximum the wall is 6.5m high, and the versatility of the Tensartech system allowed it to be easily adapted to the proposed layout. In total around 1,200m² of wall face was constructed.
