000020114 001__ 20114
000020114 005__ 20170118182355.0
000020114 04107 $$aeng
000020114 046__ $$k2017-01-09
000020114 100__ $$aWotherspoon, Liam
000020114 24500 $$aAssessment of the Degree of Soil Stiffening From Stone Column Installation Using Direct Push Crosshole Testing

000020114 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000020114 260__ $$b
000020114 506__ $$arestricted
000020114 520__ $$2eng$$aThis paper outlines the results of a full-scale field testing program designed to assess the degree of soil stiffening resulting from the installation of shallow stone columns. Stone columns with similar area replacement ratios were installed in soils ranging from clean sands to sandy silts at a number of sites in Christchurch, New Zealand for liquefaction mitigation. Direct-push crosshole tests were performed before and after ground improvement using custom-built cone sensors to measure compression wave (V p ) and shear wave velocity (V s ) at 0.2 m depth intervals. Tests were performed across stone column to characterise the composite properties of the soil/column, and in-between stone columns to characterise the properties of the soil within the improved zone. Generally, the stone columns were effective at stiffening clean sand soil profiles, with the effectiveness of the technique shown to reduce in soils with higher fines content. Near the ground surface the stone columns were shown to be less effective at some locations, with the lack of confinement at these shallow depths preventing significant increases in stiffening, as indicated by V s . A significant lowering of V p was also identified at some sites after installation, indicating reductions to the degree of soil saturation. The change in the degree of saturation over time is a topic of interest for future study, as unsaturated soil conditions have the potential to increase liquefaction resistance.

000020114 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000020114 653__ $$aStone columns; ground improvement; direct-push crosshole

000020114 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000020114 720__ $$aWotherspoon, Liam$$iCox, Brady$$iIi, Kenneth Stokoe$$iAshfield, Dan$$iPhillips, Richard
000020114 8560_ $$ffischerc@itam.cas.cz
000020114 8564_ $$s317275$$uhttps://invenio.itam.cas.cz/record/20114/files/593.pdf$$yOriginal version of the author's contribution as presented on USB, paper 593.
000020114 962__ $$r16048
000020114 980__ $$aPAPER