Determination of design parameters for solidification-stabilization soil improvement in retaining structures-Article

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The paper examines the use of solidification-stabilization (S-S) treatment to reuse polluted, soft seabed sediments as backfill behind quay retaining walls. Treating sediments with cement, lime, or other binders can reduce pollutant leaching while avoiding the high costs and environmental impacts of transport and landfill disposal.<br /><br />The authors review established design principles for stabilized soils and discuss laboratory data from port-development projects. Stabilization changes soil behavior by increasing its yield stress and shear strength; strength depends on the binder, curing time, surcharge during curing, and loading mode. Compression and extension can produce different failure strengths, so retaining-wall design should reflect the actual stress conditions rather than apply a single strength value. Undrained strength can be assessed with unconfined compression tests or estimated using relationships based on oedometer and triaxial testing.<br /><br />The data show substantial variation in strength between sites and binder mixes. Strength generally continues to increase for at least a year, and applying surcharge during curing can reduce water content and markedly improve strength. Accordingly, the authors recommend site-specific testing to establish the relationship between binder content, curing time, and strength, as well as quality control during treatment to adjust binder dosage to sediment conditions. Where practical, surcharge should also be applied in the field after placement.<br /><br />The paper concludes that S-S soil can be a beneficial backfill material, but its distinct curing behavior and load-dependent strength must be incorporated into rigorous retaining-wall design.

Keywords

solidification-stabilization

seabed sediments

quay retaining walls

soil stabilization

binder dosage

unconfined compression

curing time

shear strength

pollutant leaching

backfill material