A new approach to transformation of micro analysis into macro analysis of forces to study the dynamic behaviour of riverbank morphology

Abstract

ABSTRACT Due to complex nature of the riverbank erosion and owing to action of wide variety of forces on the particles, it is an uphill task for the researchers to find a general approach to riverbank failure mechanism. Here, a planar failure-block of right-angled trapezoidal shape spanning to the tension crack has been considered. Transformation of inter-particle microscopic forces into macroscopic forces has been made to analyse the stability of the block. Stability of the failure block is a function of the bank erosion rate in terms of the escape velocity. Moreover, varying free surface water level has been investigated to study the dynamic behaviour of the bank. With the increasing number of base particles in the tension crack from 10 to 100, escape velocity increases by 8.47% as the water level rises and 10.74% as it falls. Similarly, the increase in escape velocity with free surface water level height from 0 to full height of the tension crack is 39.4% as the water level rises and is 48.4% as water level falls. Rising water level increases hydrostatic confining pressure force, which is a resistive force. This increases the escape velocity continuously leading to greater stability of the mass.