Popis: |
In June 1981, a 10M high embankment constructed for the northern sector of the M25 orbital motorway failed shortly after completion of the bulk earthworks. The factor of safety calculated by conventional slip circle analysis in terms of total stress was in excess of 2 at the time of failure. This paper describes the events leading up to the failure, and the failure itself. The scope of the site investigations is set out, together with details of the analyses carried out; these lead to various conclusions concerning the reasons for failure. To minimize disruption to the contract, remedial works had to be specified at various points in time. All of these aspects are examined in the context of the present state of technical knowledge, in order to derive lessons to be learnt fron the incident. (Author/TRRL) |