6 000 m2 base slabs raised
Settlement to base slabs at a rail depot in Farnham, near London, threatened to disrupt rail operations in south-east England. The 60-year-old slabs had been gradually settling for many years due to compaction of fill material, drainage & washout problems, and the increased weight of modern rolling stock. The problem had reached a point where a crucial, 6,000 sq metre maintenance shed, vital to timetable operations, was at risk of closure due to unsafe ground. URETEK were contracted to solve the problem without disruption to timetables.
To stabilise base slabs over 6000 sq metres and raise the rails to level. Settlement of the slabs had led to speed restrictions for the locomotives, and fears of derailment. Adding ballast would have only been a temporary solution, and was unable to be completed quickly enough. Piling was ruled out due to cost. Breaking out and replacing the slabs was rejected due to the large area to be treated.
URETEK's Geopolymer Injection processes were applied to the 6,000 square metres of slabs.
Within a 5 week period, 6000 square metres of slabs were stabilised and lifted to tolerances of +/- 10mm over 10 sq metres, with no disruption to the operations of the shed.