Bearing capacity improvement of square footing by micropiles.

Micropiles are have been effectively used in many ground improvement applications to increase the bearing capacity and reduce settlement, particularly in strengthening existing foundations. This paper presents the results of laboratory model tests on the behavior of a square footing supported on micropiles. The parameters varied in the study include micropile diameter, length, spacing between the micropiles and distance of micropile from the edge of the footing. Bearing capacity of unreinforced and reinforced footings is determined and bearing capacity improvement factor and settlement reduction factors are evaluated. The results are then analyzed to study the effect of each parameter. The improvement of bearing capacity is noticed when the diameter and length of micropile increases and spacing between the micropiles and distance of micropile from edge of footing decreases. [ABSTRACT FROM AUTHOR]