Uniformity of lime-cement columns for deep mixing : A field study

• A field study of the mixing process of lime-cement columns for deep mixing has been carried out at a test site in Håby, Sweden. The study aimed to investigate the influence on the stabilisation effect and the coefficient of variation for excavated columns, when a number of factors related to the installation process were varied. The influencing factors investigated were the retrieval rate, number of mixing blades, rotational speed, air pressure in the storage tank, and diameter of the binder outlet hole. A large number of hand-operated penetrometer tests were carried out on the excavated column cross-sections. Statistical multifactor analyses were used to evaluate the influence on the stabilisation effect and the coefficient of variation of the varied factors. The results showed that the retrieval rate and the number of mixing blades were found to have a significant effect. The effect of rotational speed and the diameter of the outlet hole were found to be insignificant. The field study showed that the strength and deformation properties of the soil and the upper pair of mixing blades, with respect to the binder outlet hole, had a major influence on the binder dispersion over the column cross-section. The blade rotation number can be used as an indirect value of the mixing work and can be used as a measure of the mixing tool effectiveness.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Geoteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Geotechnical Engineering (hsv//eng)

Keyword

ANOVA

Deep mixing

Field test

Influencing factors

Lime-cement columns

Mixing process

Publication and Content Type

ref (subject category)

art (subject category)