Determining Bishop's parameter χ based on pore size distribution

Extension of the effective stress concept to unsaturated soils has been a major concern for decades. Recent studies significantly contributed understanding fundamentals behind Bishop's parameter χ, which is generally used define soils. An examination recently proposed methods showed that contribution suction was often overestimated, especially in high range. In this study, considering soil pores with different sizes contribute differently overall hydro-mechanical behaviour, new method determine χ proposed. The key variable ratio change water volume macropore void due loading at constant suction. Shear strength data weakly expansive clay were validation. A good agreement obtained between prediction and measurement, indicating validity method.