Modelling wetting collapse behaviour in unsaturated granite residual soil

• Published in: Unsaturated Soils: Research and Applications - Proceedings of the 6th International Conference on Unsaturated Soils, UNSAT 2014
• Main Author: Md.Noor M.J.; Mohamed Jais I.B.
• Format: Conference paper
• Language: English
• Published: Taylor and Francis - Balkema 2014
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901619561&partnerID=40&md5=86ce4426121710ea5daf11d57a4489ba

Wetting collapse is referred to settlement due to the rise of groundwater table. The complexity of this behaviour has never been explained in existing soil models since its mechanics is not compliance with the effective stress concept. This is settlement under effective stress decrease whereas the net stress is maintain constant. During inundation, the reduction of suction causes the reduction in the shear strength which is the settlement resisting factor. Even though the driving factor which is the net stress is constant the settlement is still triggered since the resisting factor is reduced. The overall concept is named as effective stress and shear strength interaction. The Curved Surface Envelope Soil Shear Strength Model (CSESSSM) will be used to characterize shear strength against net stress and shear strength against suction. The Rotational Multiple Yield Surface Framework (RMYSF) established from the model is used to demonstrate the occurrence of wetting collapse when suction is loss under the same net stress which cause the mobilized shear strength envelope to rotate towards the failure envelope. Modeling wetting collapse in modified Rowe's cell was conducted to demonstrate the settlement in one-dimensional compression due to inundation wetting in partially saturated granite residual soil and will be explained in detail in this paper. © 2014 Taylor & Francis Group, London.