Mohd Jamaludin Md Noor

Volume Change Behaviour of Clay by Incorporating Shear Strength: A Review

Soft clay settlement is well known as a major problem in the civil engineering structures such as highways, buildings and bridges. The problem arises due to the current settlement analysis which is derived from the effective stress concept. It considers the volume change increase with the increase in the effective stress, whereas the settlement problem is not always happened in this fashion. In fact, the inundation problem that causes the sudden settlement during the effective stress decrease really put a tremendous blow to this concept. It is proved that the empirical effective stress concept that is widely used by the engineer is not the appropriate analysis. In fact, this is one of the main factors that cause many settlement problems. The objective of this paper is to review several settlement models available in the literature and to distinguish the applicability of the model to predict soil settlement. It also reviewed the volume change behaviour by incorporating shear strength concept that is more appropriate to predict the settlement. Hopefully, this paper will help the new researcher to uncover the unique behaviour of clay settlement and at the same time will reduce the settlement problem cases.

Prediction of soil stress-strain response incorporates mobilised shear strength envelope of granitic residual soil

The concept of effective stress has been the principal concept in characterizing soil volume change behavior in soil mechanics, the settlement models developed using this concept have been empirical in nature. However, there remain certain unexplained soil volume change behaviors that cannot be explained using the effective stress concept, one such behaviour is the inundation settlement. Studies have begun to indicate the inevitable role of shear strength as a critical element to be incorporated in models to unravel the unexplained soil behaviours. One soil volume change model that applies the concept of effective stress and the shear strength interaction is the Rotational Multiple Yield Surface Framework (RMYSF) model. This model has been developed from the soil-strain behavior under anisotropic stress condition. Hence, the RMYSF actually measure the soil actual elasto-plastic response to stress rather than assuming it to be fully elastic or plastic as normally perceived by the industry. The frameworks m...

The Shear Strength Characteristics of Kota Samarahan Sedimentary Soil

The current approaches and practices for determination of shear strength of soil that widely used in Malaysia is Mohr–Coulomb failure envelope theory. This theory states that the failure envelope is linear to the effective stress on the shear strength versus effective stress graph. The problem with this current approach when the linear envelope is produced and the shear strength at low stresses was extrapolated by the higher level of stresses. By applying the nonlinear method with a slight curve envelope when approaching the origin of the graph seems to show that the nonlinear failure envelope takes into consideration the value of shear strength at a very low level of stresses.

Prediction of Stress–Strain Response for Malaysian Granitic Residual Soil (Grade VI) in a Range of Effective Stresses, According to Rotational Multiple Yield Surface Framework

The conventional soils volume change models which are based on the effective stress concept are not accurate to model true volume change behavior of unsaturated soil solely. It seems that the effect of shear strength in interaction of effective stress is essential to be incorporated in these frameworks. Rotational multiple yield surface framework (RMYSF), which introduced by Md.Noor and Anderson (16th South East Asian Geotechnical Conference Kuala Lumpur, 2007) [21] is developed based on the concept. In this paper, the framework has been examined for Malaysian granitic residual soil grade VI. With the aim of this process, the stress–strain curves were predicted using the framework. Beside that, the stress–strain curves have been obtained from consolidated drained triaxial tests under various effective stresses and then the results were compared with the predicted ones. The result shows a good agreement between the laboratory stress–strain curves and predicted ones from the framework.

Laboratory Test Methods for Shear Strength Behavior of Unsaturated Soils Under Suction Control, Using Triaxial Apparatus

The shear strength of an unsaturated soil is controlled by two variables; net stress and suction. The conventional triaxial machine which is used for obtaining the shear strength of saturated soils cannot be used for unsaturated soil conditions due to weakness in suction control during the consolidation and shearing stages. In the view of this, the standard triaxial apparatus needs to modify and develop for unsaturated conditions. The main aim of this paper is devoted to give a description of current methods and techniques using triaxial apparatus for obtaining data to interpret the accurate shear strength behavior of unsaturated soils. In additional some of the key aspects related to air diffusion and volume change measurement are highlighted.