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Innovative Solution of King Post Walls combined with CSM Panels
Solution Innovante de Parois Berlinoise combinée avec des Panneaux de CSM
Pinto A., Tomásio R., Godinho P.
JetSJ Geotecnia Lda
ABSTRACT: The aim of this paper is to present the main design and execution criteria related with the innovative solution of earth
retaining walls combining the King Post Walls (Berlin) with the CSM (Cutter Soil Mixing) panel’s technology. A case study where
the solution was applied is presented, confirming the solution excellent overall performance.
RÉSUMÉ : Dans cet article sont présentés les critères principaux de conception et d'exécution de la solution innovante qui combine
des parois de soutènement (Berlinoise) avec de panneaux de CSM (Cutter Soil Mixing). Un cas d´étude avec ce type de solution est
présenté, confirmant l’excellente performance globale de la solution.
KEYWORDS: cutter soil mixing, Berlin wall
1 INTRODUCTION
The traditional and widespread King Post Walls (Berlin)
technology has some disadvantages, mainly the excavation
schedule as well as the confinement reduction of the supported
soil during the excavations works, mainly in cohesionless soils
(Figure 1). In order to overcome this disadvantage, the Berlin
solution can be combined with the CSM technology, which acts
as a preliminary treatment of the supported soil.
Figure 1. View of the confinement reduction of the supported soil
during the excavation works using the Berlin Wall technology.
As an example of this combined solution the case of the
enlargement of a railway platform, in order to accommodate the
new infrastructures at the connection between two main railway
lines in Lisbon, Portugal, is presented (Gomes Correia et al.,
2013), following previous works using the CSM technology
(Pinto A. et al., 2011). For this purpose it was necessary to
perform several excavations with 13m of maximum depth. Due
to neighbourhood conditions, three retaining structures (M1, M2
and M3) were built using the combination of Berlin wall with
the CSM technology. In this paper the case of the M3 wall is
presented, with 13m height and about 66m wide (Figure 2).
Figure 2. Wall M3 location.
2 MAIN CONDITIONS
2.1 Geological and geotechnical conditions
The local geological conditions were heterogeneous. The
excavation works intersected, from the surface, heterogeneous
landfills and Miocene medium dense to dense sands and
sandstones. The ground water table was located about 5m above
the final excavation level (Figures 3 and 6).
2.2 Other conditions
The main neighbourhood conditions included the existent
railway lines (under operation and connecting the two
Portuguese main cities), several industrial and sensitive
buildings, located behind the walls, as well as the important
viaduct of the Marechal Gomes da Costa Avenue, over the
railway lines, pointing out the importance to control the walls
deformation during and after the excavation works (Figure 4).
