Behavior of anchored walls in soils overlying rock in Stockholm

Abstract

The deformations of retained soil and retaining walls are of importance for the design of a deep excavation in soft soils. The beneficial influence of bedrock underlying the soils on the behavior of the retaining wall needs proper evaluation. This contribution shows a case study on deep excavation in soft soils overlying bedrock at the South Link tunnel project in Stockholm. The behaviors of sheet pile walls and retained soils at the South Link show that both lateral displacement and settlement are larger than the magnitude from similar case histories. Exemplified by a test section, the features of lateral displacement are analyzed with monitoring and PLAXIS simulating results. The analysis results indicate that the displacement mainly takes place during the upper excavations in a section and the beneficial influence of bedrock may be overshadowed by the low strength of soils, where depth of the excavation bottom to bedrock is larger than the excavation depth.