Determination of the hydraulic conductivity function of grey Vertosol with soil column test

Abstract

Expansive soils exhibit swell-shrink behaviour in wet-dry periods resulting in distresses on light-weight structures founded on/in them. Therefore, it is essential to investigate the climate-ground interaction when designing structures on expansive soils. Laboratory-based models are preferred to investigate the climatic-ground interaction of expansive soils due to the uncontrollability of the boundary conditions and expenses associated with field monitoring. More flexibility in analysing the climatic-induced hydraulic responses in expansive soils can be achieved by finite element modelling of data from physical model tests. However, these laboratory-based models regularly encounter the effects of boundary flaw, preferential flow paths and entrapped air that needs to be accounted for when numerically simulated. In this study, the authors aim to numerically model the hydraulic responses in an instrumented Vertosol soil column (ISC) under controlled laboratory conditions. The effects of the preferential flow paths and boundary flaws were incorporated into a modified hydraulic conductivity as a practical approach to model the hydraulic responses in ISC. Influence of the entrapped air was rectified by a suitable correction factor. These findings present a practical method for geotechnical practitioners to accurately estimate the suction and volumetric water content profiles in laboratory-based expansive soil model tests.

Factors Controlling Rainfall-Induced Slope Instability of Natural Slopes in North Maleny, Queensland

“…Their results [5] confirmed that the slopes with an inclination less than 32 0 are theoretically stable even at extreme rainfall conditions. Further, it proved that a slope with a lesser saturated coefficient of permeability (i.e., less than 10 -6 m/s) and steeper slope inclinations up to 63 0 would not fail under shortterm extremely high rainfall intensities [16,17].…”

A Practical Approach to Determine the Temperature Correction for Ec-5 Moisture Sensors Embedded in Vertosol

“…Unsaturated soil behaviour and the soil properties are significantly dependent on the soil moisture conditions [1][2][3][4][5]. Therefore, it is imperative to identify accurate methods and instrument to investigate the moisture variations in soil profiles [1][2][3][4][5][6][7][8]. These investigations include laboratory-based element tests, model tests and field-based investigations.…”

“…These investigations include laboratory-based element tests, model tests and field-based investigations. The moisture sensitivity of expansive clays are considerably greater compared to non-reactive soils and hence, much attention has been given to these soils lately [3][4][5][6][7][8][9][10][11][12].…”

Shear Strength of Unsaturated Expansive Soils From Queensland Natural Slopes

“…Geotechnical site investigation is of prime importance in ensuring the safety of civil engineering structures related to embankments, pavements and landfills [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Therefore the understanding of the soil interface shear strength is vital in designing and analysing the stability of geotechnical structures [15][16][17][18][19][20].…”