Finite element analysis of mixed-in-place (MIP) columns supporting excavations in slopes considering tension-softening

Abstract

The use of mixed-in-place (MIP) columns can be considered as an attractive alternative to sheet pile, diaphragm or bored pile walls for supporting deep excavations, even in difficult ground conditions. In this paper, results from a numerical study based on a case history are presented, where MIP columns are used to support an excavation in a slope. The special feature of this project is that tied-back anchors were not feasible as an additional support measure because structural elements were not allowed to be installed within the neighbouring ground. Thus, the MIP columns were placed in such a way that they formed an arch, including buttresses capable of transferring the load acting on the backside of the wall into the ground. In this study, an advanced constitutive model for the MIP columns is applied to capture the development of possible cracking. Variations in geometry have been performed to investigate the potential for optimization. Finally, some analyses have been conducted to show that a design of such structures compatible with Eurocode 7 requirements is perfectly feasible by means of the finite element method.

Numerische Studien zur Sicherung von Baugruben und Geländesprüngen mit Stützscheiben

“…In und wurde eine eingehende Untersuchung der äußeren Standsicherheit und der inneren Tragfähigkeit der Stützscheiben präsentiert und diskutiert. Die Studien wurden mit den geometrischen Abmessungen der Stützscheibe im Einbindebereich begonnen, die sich in etwa als Bemessungsergebnis nach der Palisadentheorie mittels analytischem Ansatz ergibt (vgl.…”