Design and performance of a compacted clay barrier through a landfill

This paper presents the construction and performance details of a compacted London Clay barrier that was designed to prevent any leachate or methane p enetrating a stretch of the cut and cover box section tunnel of the London Heathrow Express Rail Link. The barrier was constructed with London Clay th at was spoil from concurrent bored tunnelling operations on adjacent sites. Laboratory investigations carried out on the compacted London Clay are pre sented in the paper. These indicated that it was possible to design the cla y surround to function as a barrier protecting the structure from the ingre ss of the leachate. Field monitoring using magnetic extensometer gauge meas urements indicate that the consequent ground movements are lower than that predicted by the laboratory tests. (C) 2001 Elsevier Science B.V. All right s reserved.