Analytical Analyses of a Failure Department Project in Northern Ireland

Abstract

A development of 2 and 3 storey town houses and 4 storey apartment blocks were constructed on a site bordering the River Erne in Enniskillen, Northern Ireland. Within two years of completion, the ground deformations around the buildings constructed on the ‘load transfer platform’ (LTP) were becoming noticeable. Sometime later, the pile caps ‘punched’ into the material above, causing significant deformation. According to detailed investigation and assessment of the cause of failure (Milligan, 2006) [1], the problems were caused by excessive and continuing deformation of the load transfer platform. The analytical analyses have been used to investigate the performance of reinforced piled embankment over very soft soil to understand the reason for failure. Results showed that subsoil could give a major contribution to overall vertical equilibrium, and reinforcement can only give contribution at relatively large settlement. The performance of actual structures has on occasions been problematic when relying on multiple layers of relatively low strength geogrid.