Collapse settlement of unsaturated soil from effective stress and shear strength interaction of soil

11th International Conference on Geotechnical Engineering in Tropical Regions;1st International Conference on Highway and Transportation Engineering 2019

矿业工程;运输工程

Mohamed Jais, I.B.^1 ; Md Noor, M.J.^1

Geotechnical Forensic Specialised Initiative Group, Faculty of Civil Engineering, Universiti Teknologi MARA, Selangor, Shah Alam, Malaysia^1

关键词: Complex settlement behaviour;    Consolidation settlement;    Dissipation of excess pore water pressure;    Partially saturated soils;    Pressure plate extractor;    Saturated and unsaturated soils;    Soil-water characteristic curve;    Unsaturated shear strength;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/527/1/012020/pdf
DOI  :  10.1088/1757-899X/527/1/012020

来源: IOP

【 摘 要 】

Consolidation settlement is the volume change behaviour due to dissipation of excess pore water pressure in saturated conditions. However, in a partially saturated condition, suction plays an important role in governing settlement behaviour. Besides, it also influences the shear strength of the soil by providing additional cohesion (termed apparent cohesion, cs) due to the existence of suction in the shear strength against suction axis. The shear strength decreases as the soil becomes fully saturated i.e. suction is reduced to zero, thence causes the apparent cohesion reduced to zero. Apparently, the shear strength has strong influence on the volume change behaviour. Therefore, a comprehensive review of the effective stress and shear strength interaction was conducted to verify this. The objective of this research is to verify the effective stress and shear strength interaction for both saturated and unsaturated soil conditions and to evaluate the complex settlement behaviour due to inundation at constant net stress, which has puzzled geotechnical practitioners. These conditions are tested and verified using the double wall triaxial test apparatus to determine the unsaturated shear strength of soil, the pressure plate extractor to produce Soil Water Characteristic Curve (SWCC) and modified large Rowe's cell apparatus to simulate the loading and wetting collapses of partially saturated soils.