TURBULENT BORES-INDUCED SCOUR AND PORE PRESSURE VARIATION AROUND A VERTICAL STRUCTURE

Marieh Rajaie,Amir H Azimi,Colin D Rennie,Ioan Nistor

doi:10.9753/icce.v36v.sediment.29

Abstract

Pore pressure and scour formation around coastal structures have been investigated in the past which led to a relationship between the hydrodynamics of tsunami waves and sediment erosion around coastal structures. With the objective of developing a comprehensive model to assess the interaction of hydrodynamic conditions, induced scour, soil pore pressure, and beach slopes, this novel study aims to examine (1) the effect of hydrodynamic forcing factors such as bore depth on scour and pore pressure generation on both horizontal and inclined bed conditions and (2) the effect of bed slope on the scour and pore pressure development and (3) the influence of the soil pore pressure on scour around a square shaped structure.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/dTQ-_GLhtzs

Highlights

Effects of the devastating tsunami events such as the 2004 Indian Ocean Tsunami and the 2011 Tohoku Tsunami demonstrated the importance of studying the hydrodynamics and bed sediment transport during such disasters
It was found that the maximum pore pressure due to the bore front occurred over inclined beds, whereas the maximum scour took place on horizontal beds
The sediment erosion due to the motion of the turbulent bore front reached the equilibrium over a shorter time span on inclined beds compared to that on horizontal beds

Summary

Introduction

Effects of the devastating tsunami events such as the 2004 Indian Ocean Tsunami and the 2011 Tohoku Tsunami demonstrated the importance of studying the hydrodynamics and bed sediment transport during such disasters. Scour of sediment during tsunami events was shown to have a close link with pore pressure and soil liquefaction. Pore pressure and scour formation around coastal structures have been investigated in the past which led to a relationship between the hydrodynamics of tsunami waves and sediment erosion around coastal structures. [Young et al 2008] conducted laboratory experiments to study tsunami induced liquefaction failure on a sand bed with two different slopes: 1/5 and 1/15. The correlation between soil liquefaction and scour showed that as the bed slope increased, the peak pressure increased as well. Despite research studies in this field, further investigations are needed to better understand the combined and synchronous effects of the influential variables

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Conclusion