PERFORMANCE AND LOAD DISTRIBUTION IN LIME-CEMENT STABILIZED SOIL AS SUPPORT FOR DEEP SUPPORTED EXCAVATION IN MARINE CLAY-Paper

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The study investigates how lime-cement-stabilized soil supports sheet pile walls during deep excavation in sensitive Norwegian marine clay. At the Campus Ullevål site in Oslo, researchers monitored a six-meter-deep excavation using inclinometers placed within stabilization panels and in the untreated soil between them. Measurements were compared with two- and three-dimensional PLAXIS models.<br /><br />The excavation used sheet pile walls, deep-mixed lime-cement panels installed perpendicular to the wall, and staged excavation with temporary struts and a concrete slab. Monitoring showed that most movement below the excavation floor occurred while the central area was excavated. The untreated soil between panels generally moved slightly more than the stabilized panels, indicating that the two materials do not interact completely.<br /><br />The 3D model reproduced measured behavior and load distribution relatively well. It showed that earth pressure is transferred from the sheet pile wall to the stiffer lime-cement panels, especially near the top of the panels; load sharing becomes more even with depth. The 2D model, which represents the stabilized ground using averaged properties, overestimated deformation below the excavation floor and underestimated cantilever movement of the wall. Its conservative results were attributed to using design strength and stiffness values lower than those of the installed material.<br /><br />The findings support using 3D analysis to capture load transfer between panels and surrounding soil. Incomplete interaction should be considered where panel spacing is large, although it had little practical effect at this site. Overall, conventional 2D design was conservative for the studied excavation.

Keywords

lime-cement stabilization

sheet pile walls

deep excavation

Norwegian marine clay

PLAXIS modeling

inclinometer monitoring

stabilized soil panels

load transfer

3D numerical analysis

Oslo Campus Ullevål