Resilience and Vulnerability Analysis for Restoration After Tsunamis and Floods: The Case of Dwellings and Industrial Plants - Post-Tsunami Hazard: Reconstruction and Restoration - page 244

Fig. 16.7 Tsunami path from the epicenter to the shore, inland and run-up (Source: Mebarki et al.
2014 in Springer 2014)

16.2.3.3 Vulnerability Modeling

The structural response of the cylindrical metal tanks to the tsunami hydrodynamic
effect concerns the following phenomena, (Fig. 16.8 ):

- Buoyancy and uplift of the tanks,

- Debris impacts, perforation or collapse of tanks or sections of tank with the ensu-

ing escape of stored products (oil, liquids and gases),

- Excessive bending or shear, as well as sliding and overturning,

- Lateral (circumferential) and longitudinal buckling,

- Rupture of any pipes connected and tank roofs.

Besides the tsunami's height and its velocity, the tank-fullness ratio is also con-
sidered as a random variable. Its distribution depends on conditions of service: fill-
ing or emptying the tanks. A theoretical Gamma distribution is adopted. However,
any experimental feedback could help in defining an adequate distribution for
industrial plant use. These parameters influence tank resistance to external flow
pressure: the weight of the tank and the liquid that compensates for the uplift effect,
the overturning moment, the sliding effect (the friction coefficient is adopted as hav-
ing a constant value all over the contact of the tank with its concrete support on the
ground) as well as circumferential buckling. The numeric values adopted are not
provided in detail in this study as its purpose is to discuss relative influences of each
potential failure of the tanks depending on the tsunami's height and velocity, in the
case of small or large tanks. The failure event, Ef, f , is defined as a combination of
elementary failures:

N N

e e

 

E = E and P = P E

(16.8)

f fi , f fi ,

i = 1 i = 1

Where:E f = failure event of the system; Pf f = failure probability or vulnerability;
E f,i = i- th failure event among the total number N e of failure events: for instance i = 1
for Buoyancy, i = 2 for perforation by debris impacts.