An objective framework for determination of the air-entry value from the soil–water characteristic curve

• Published in: Results in engineering 2021-12, Vol.12, p.100298, Article 100298
• Main Authors: Soltani, Amin, Azimi, Mahdieh, Boroomandnia, Arezoo, O'Kelly, Brendan C.
• Format: Article
• Language: English
• Subjects: Air-entry value; Mathematical translation; Soil–water characteristic curve; Unsaturated soil
• ISSN: 2590-1230; 2590-1230
• DOI: 10.1016/j.rineng.2021.100298

The air-entry value (AEV) suction, marking the transition between saturated and unsaturated soil mechanics, is arguably the most important parameter interpreted from the soil–water characteristic curve (SWCC); its accurate determination being essential for the prediction of unsaturated soil properties. The AEV is commonly obtained by a subjective and time-consuming graphical construction. This micro-article proposes an objective framework, developed based on a practical mathematical translation technique, for the AEV determination. Explicit equations for the AEV are derived based on eleven well-established SWCC fitting functions, covering a wide range of functional complexities. In addition to its objective nature (providing unique interpretations of the AEV), the proposed framework complements numerical implementations of unsaturated soil constitutive models. •Key mathematical attributes for eleven well-established soil–water characteristic curve fitting functions are presented.•An objective framework is developed based on mathematical translation for the determination of the air-entry value.•The framework complements computational analyses and numerical implementations of unsaturated soil constitutive models.