Stability Analysis of a Riverbank for Different Microstructural Arrangements of the Particles

Abstract

River morphology is a subject of great interest to the researchers for long due to its dominant influence on lifestyle, economy and agriculture. It is closely related to the stability of the bank surface. The dynamic nature of the riverbank is linked to the continual variation of water level through the river. In the present study, two different microstructures for the particle arrangement have been analysed to study the stability of the dynamic river system. The microstructures under consideration are based on “Truncated Pyramid Model (TPM)” and “Simple Cubic Model (SCM)”. A comparison has been made between these two models. In this case, inter-granular cohesive force, hydrostatic force, weight of the particle and pore-pressure force play the major roles. The conservation of angular momentum principle has been applied to arrive at the escape velocity of the particle, which is the key parameter for stability analysis. A higher escape velocity indicates that a particle is more stable at the micro level. For different microstructural arrangements of particles, both the situations of falling and rising water level have been considered in the present analysis for three different particle sizes (300, 400 and 500 μm of radii) in fully submerged conditions. Also, variation of the escape velocity with the inter-granular distance has been studied in a quantitative manner. It has been found that TPM is more stable than SCM in a dynamic flow situation.