Resilience and Vulnerability Analysis for Restoration After Tsunamis and Floods: The Case of Dwellings and Industrial Plants - Post-Tsunami Hazard: Reconstruction and Restoration - page 236

Hazard Modeling

Hydraulic river discharge is modeled by an extreme distribution whose parameters
have been identified on the basis of available historic records. Monte Carlo simula-
tions are made in order to derive the probabilistic distribution of the hydraulic
charge at each location in the floodplain (Valencia 2006 ; Mebarki et al. 2012 ).
Although scouring, erosion, and the presence of debris and mud may have an influ-
ence, the simplified hydraulic model does not take their effect into account. However,
this theoretical model provides acceptable results (flow height) when compared to
the stream height observed in the village during the 1995 historic flooding. Gumbel
distribution is well adapted for flow pressure, (Valencia 2006 ; Mebarki et al. 2012 ):

2

V

p = r . H +

w

(16.3)

w w w

2 . g

Where:p w [ Pa ] = Hydraulic pressure generated by flows on the masonry walls;
H w [ m ] = Height of the flow; V w [ m/s ] = Velocity of the flow; g [ m/s 2 ] = universal
gravity acceleration; ˁ w [ N/m 3 ] = specific weight of water.

Vulnerability Modeling

Accurate assessment of the vulnerability of constructions requires sophisticated
methods. However, a quick visual inspection by qualified and trained engineers can
also provide a good estimated approach to vulnerability. Available evaluation forms
are developed and calibrated for this purpose. Methodology is summarized as fol-
lows for the present study (Mebarki et al. 2008 , 2012 ):

- A set of structural parameters is selected for governing the vulnerability of

masonry dwellings under hydro-dynamic pressure: the number of stories, the
quality of materials; wall geometry, wall thickness, the state of conservation, the
slope of the terrain and foundations, columns and beams, openings (doors and
windows), horizontal and vertical regularity, wall orientation, the type of floor
slab, location, environment, debris, and the existence of basements. Their influ-
ence is such that, depending on their values, the construction will be graded as
being “A- Very safe”, or “B- Safe”, or “C- Dangerous”, or “D- Very dangerous”,
(Fig. 16.3 ), (Mebarki et al. 2008 , 2012 ). By means of inspection, the construc-
tion “vulnerability identity matrix” is identified as:

…
… () …
…

I = I ij , (16.4)

v v