Bearing capacity of foundation on soil reinforced by deep mixing columns

ABSTRACT

An analytical calculation of the bearing capacity of soft soil reinforced by the deep mixing method is presented. A comparison between this result and the homogenization method using the mechanism of Prandtl is also discussed. Comparison between the results shows that the direct calculation with the kinematic approach by a rigid mechanism leads to an upper bound of the bearing capacity factor BCF larger, but very slightly, than that obtained from the approach of homogenization considering the Prandtl mechanism. The method of homogenization allows estimating the influence of the reinforcement width beyond foundation while the direct method cannot provide this estimation. It was concluded that the upper bound increases rapidly for a width ratio (width of reinforcement to width of foundation) l ≤ 1 (l is the ratio between the total width of the reinforcement and the width of the foundation), against this, the increase becomes less significant for 1 ≤ l ≤ 2, a little less steep for 2 ≤ l ≤ 3. Then, it becomes stable when l ≥ 3 which shows that ground next to the foundation is the most concerned in increasing the bearing capacity. Comparison with the homogenization method showed that the upper limit increases proportionally with the substitution factor η.

KEYWORDS:

• Bearing capacity
• column
• soft soil
• deep mixing
• homogenisation

Disclosure statement

No potential conflict of interest was reported by the author(s).