Tsunami bore impingement on the rectangular structure of different widths: Analysis of maximum impulsive force

Ocean Engineering, vol. 319, pp. 120191

Abstract

The incoming tsunami surge or bore can induce devastating pressure on the inland structure. Previous studies observed that the structure initially experiences a short-duration impact pressure during the surge or bore tip interaction. On further interaction, the maximum impulsive force occurs, followed by the quasi-static force. Moreover, previous studies noted a reduced maximum impulsive force on narrow-width structures compared to broader structures, although this observation lacked quantification. Thus, the present study experimentally understands and quantifies the impulsive force and overturning moment characteristics during the bore impact, focusing primarily on the effect of structure width perpendicular to the flow direction using seven different structure widths. Results show that the maximum impulsive force occurred at the same time for all the structure widths tested. The pressure distribution over the structure depth is found to be linear at the time of maximum impulsive force and dependent on the bore front Froude number and the structure width. For the smallest structure width tested (which is 20% of the flow channel width), an average reduction in the maximum impulsive force and overturning moment of 55% and 65%, respectively, compared to the vertical wall due to the three-dimensional splashing was observed. The structure width-to-bore depth was found to have a negligible impact on non-dimensionalized impulsive force and overturning moment. Empirical force and overturning moment equations are proposed for structural design within the present experiment constraint.

Authors 4

1. S. Harish corresponding Aachen Institute of Hydraulic Engineering and Water Resources Management

   RWTH Aachen University

   Affiliation as printed

   Institute of Hydraulic Engineering and Water Resources Management, RWTH Aachen University, 52074, Aachen, Germany

2. Holger Schüttrumpf Aachen Institute of Hydraulic Engineering and Water Resources Management

   RWTH Aachen University

   Affiliation as printed

   Institute of Hydraulic Engineering and Water Resources Management, RWTH Aachen University, 52074, Aachen, Germany

3. Venkatachalam Sriram

   Indian Institute of Technology Madras

   Affiliation as printed

   Department of Ocean Engineering, IIT Madras, Chennai, 600036, India

4. Sannasi Annamalaisamy Sannasiraj

   Indian Institute of Technology Madras

   Affiliation as printed

   Department of Ocean Engineering, IIT Madras, Chennai, 600036, India