Time-Dependent Back Analysis of a Multianchored Pile Retaining Wall

A multianchored pile retaining wall was constructed to protect the cut made for the cut and cover section of the twin Trojane Tunnel. Deformation monitoring surveys were conducted and measurements of movements were carried out throughout the construction cycle of the wall and beyond. In order to determine design parameters for the soil strata embedded in a complex geological sequence, the soil-wall interaction was back analyzed using the finite element method. The technical note describes the process of selection of material parameters through careful assessment of the laboratory data and the results of the numerical back analyses. Once selected, the parameters were verified on the other cut and cover sections of the same tunnel and later used in routine design. Generally, a good agreement between predicted and observed behavior was achieved suggesting the adequate determination of the geotechnical model and the soil parameters.