BEARING CAPACITY OF SHALLOW FOUNDATION ON COLLAPSIBLE KHONKAEN LOESS

Abstract

This research studied the bearing capacity of an isolated shallow foundation on wet and dry
Khon Kaen loess. The bearing capacity was field-tested by a static load test at various depths for dry and wet
conditions. The foundation size of 1.0x1.0 m was placed at a depth of 0.5, 1.0, and 1.5 m. Moreover, the
foundation sizes of 1.2x1.2 m and 1.5x1.5 m were placed at only a depth of 1.0 m. Four LVDTs were installed
at the four corners of the foundation to measure the settlement due to the loading. The load of 25 mm settlement
was observed and defined as a failure in this study. The triaxial test under unconsolidated undrained was
investigated as the shear strength parameters of this study. Moreover, the soil structures and soil composition
minerals were determined by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy
(EDX), respectively. The estimation of the bearing capacity of dry Khon Kaen loess from Terzaghi's theory
was closer to the field test than Meyerhof's theory. However, the estimation of the bearing capacity of wet
Khon Kaen loess from Terzaghi's theory and Meyerhof's theory was much higher than the bearing capacity in
the field. The field test showed that the bearing capacity of Khon Kaen loess was not dependent on the
foundation size and depth. Nevertheless, this study found that Khon Kaen loess's bearing capacity was affected
by its degree of saturation.