ISSN: 1945-7545
CODEN: GTJODJ
Published Online: 14 December 2007
Page Count: 14

Laboratory Procedure to Obtain Well-Mixed Soil Binder Samples of Medium Stiff to Stiff Expansive Clayey Soil for Deep Soil Mixing Simulation

Bhadriraju, Venkat
Former Graduate Student, Professor, and Doctoral Student, The University of Texas at Arlington,

Puppala, Anand J.
Former Graduate Student, Professor, and Doctoral Student, The University of Texas at Arlington,

Madhyannapu, Raja Sekhar
Former Graduate Student, Professor, and Doctoral Student, The University of Texas at Arlington,

Williammee, Richard
Materials Engineer, Texas Department of Transportation,

(Received 6 December 2006; accepted 1 November 2007)

Abstract

This paper presents a laboratory procedure to prepare well-mixed soil binder samples for simulation of deep soil mixing to stabilize medium stiff to stiff expansive clayey soils. Two natural clays were selected, and stabilized with lime, cement, and combinations of both at various proportions and dosages. Results obtained from tests conducted on identical specimens showed that the current soil-binder mixing and specimen preparation procedures have yielded homogenous and uniform treated clayey specimens. Engineering properties measured on the treated soil specimens were analyzed and ranked to arrive at the optimum binder dosages for field implementation. Concurrent mineralogical studies on selected specimens using X-ray diffraction and scanning electron micrograph studies revealed the presence of pozzalonic compounds and interwoven threads in the treated samples indicative of the mixing and stabilizing phenomenon. The recommended chemical dosages were later implemented in a field deep mixing study to construct two test pads. Several in situ wet grab samples were collected from the treated ground and were subjected to strength and stiffness tests in the laboratory. Comparisons between test results from field cores and laboratory fabricated specimens showed a good match suggesting that the formulated test protocol has provided a reasonable simulation of the DM process.

Keywords:
deep soil mixing, expansive soils, quality control, shrinkage, swell, ground improvement, shear wave velocity, shear modulus

Paper ID: GTJ100936
DOI: 10.1520/GTJ100936
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