Design construction and performance of an anchored piled wall to stabilise an active landslide

Shortly after a battered excavation had been formed on a sloping site to provide a level platform for a large retail store development, signs of unexpected slope movement were observed. A bored pile wall was proposed as a permanent solution to the stabilisation of the slope. Although a cantilever wall might have an adequate factor of safety, finite difference modelling indicated that the piles would undergo unacceptable lateral deflections. Accordingly the final design incorporated ground anchorages. Monitoring of inclinometers within the slope continued during the construction of the piles and revealed that slight movement was ongoing and did not finally cease until the ground anchorages were installed and fully stressed. The paper demonstrates the advantages of employing modern finite difference techniques in the design and prediction performance of an anchored retaining wall. These techniques lead to improved confidence with respect to the technical and financial decisions to be made regarding the scope and sequence of the various aspects of construction. Peu aprds le formation d’une fouille talutde sur un terrain en pente, dans le but de produire une plate-forme nivelde pour la construction d’un magasin de grande surface, des signes de mouvement imprevu de la pente ont dtd observes. La mise en place d’un mur en pieux fords a dtd proposde à titre de solution permanente pour la stabilisation de la pente. Bien qu’un mur à encorbellement eut dt6 susceptible d’offrir un coefficient de sdcuritd addquat, un moddle selon la methode des diffdrences finies a rdvdld que les pieux seraient soumis à des efforts de flexion latdrale inadmissibles. En consdquence, l’exdcution finale a incorpord des points d’ancrage au sol. La surveillance des inclinomdtres rdpartis au sein de la pente s’est poursuivie pendant la construction des pieux fords; elle a permis de constater qu’un ldger mouvement persistait, lequel n’a finalement disparu qu’aprds l’installation et la mise sous contrainte maximale des ancrages, L’article ddmontre les avantages inhdrents & l’usage de techniques modernes de diffdrences finies pour l’dtude et la prddiction des performances d’un mur de soutdnement ancrd. Ces techniques ont engendrd une confiance accrue quant aux ddcisions techniques et financidres concernant l’importance et l’odre d’exdcution des divers aspects de la construction.