SHEAR STRENGTH OF CLAY REINFORCED WITH SQUARE AND TRIANGULAR ARRANGEMENT OF GROUP ENCAPSULATED BOTTOM ASH COLUMNS

Abstract

Soft clay is known to be a problematic soil that consists of low shear strength, low permeability
and high compressibility where the existing soil on the given site is low with load bearing capacity, and by that
ground improvement is required. Granular column methods are being used extensively as ground improvement
technique for supporting a wide variety of structures and infrastructures. In practice, the bearing capacity on soft
clay increased by a layer of compacted sand or gravel. Bottom ash as by product of coal burning that has similar
properties to granular material can be applied as one of the stabilizing method to the existing soil. Hence, by
using bottom ash as substitute, the cost of construction can be reduced and make great progress of a growing
awareness of the sustainable engineering. This research discusses the results of the improvement in the shear
strength of soft clay after being reinforced with a group of square and triangular encapsulated bottom ash
columns. The physical and mechanical properties of the materials used such as kaolin and bottom ash were
determined. The results show that kaolin can be classified ad clayey soil and bottom ash has similarities of
characteristic with granular material. A total of 52 unconfined compression tests had been conducted on kaolin
specimens to determine the shear strength. The diameter for specimen is 50 mm and 100 mm in height. The
diameter of bottom ash columns are 10 mm and 16 mm respectively and the height of the column are 60 mm, 80
mm and 100 mm. The group columns have been arranged in square and triangular pattern. It can be concluded
that the shear strength parameters were improved based on the different diameter and the height of the column.