The Relationship between Soil Suction and the Maximum Unsaturated Undrained Shear Strengths of Compacted Khon Kaen Soil

Abstract

The objective of this study was to evaluate the maximum unsaturated undrianed shear strengths of compacted Khon Kaen soil, which were determined from UU triaxial tests. The samples were compacted at 85% of maximum dry density by standard method. The samples were not measured soil suction during the test, but rather estimated soil suction from the soil water characteristic curve (SWCC) based on the volumetric water content of the sample during the test. The drying SWCC for the compacted Khon Kaen loess was determined from three methods, which were a hanging column method, a pressure plate method and an isopiestic humidity method. The maximum unsaturated undrained shear strength of compacted Khon Kaen loess was investigated in the Transition Zone. The relationship between soil suction and the unsaturated undrained shear strength of compacted Khon Kaen soil was a good related in the form of exponent of the value of R² = 0.98.