PSI - Issue 44

Alessandro Fulco et al. / Procedia Structural Integrity 44 (2023) 195–202 Alessandro Fulco et al. / Structural Integrity Procedia 00 (2022) 000–000

197

3

The restoration cost of a damage state of the structural elements can be defined thanks to a data-base of costs embedded in the procedure. The costs are differentiated for different types of structural elements: columns, walls, deep beams, low beams (beams with wide section having the depth of the floor). Costs have been stored as a function of the following variable parameters: cross section area, A; story height, H; beam span, L; reinforcement percentage, ρ ; cover thickness, c; floor depth, s. The data-base has been built through simulations of rehabilitation costs performed using Italian standard construction pricelists and, most of all, the pricelists for the reconstruction works after the 2016 Central Italy Earthquake, suitably adjusted taking into account the price increases of the last period. In particular, the costs of the basic structural works as well as those related to the so called ancillary works have been defined for each damage state. The following retrofitting works have been assumed: cracking repair with resin or mortar injections, for state D1 (ST) ; concrete removal, surface cleaning, passivating treatment of reinforcing bars, section re-profiling, for state D2 (ST) ; concrete removal, surface cleaning, replacement and supplementation of bars, continuity holes, restoration with section re-profiling, for state D3 (ST) ; r/c jacketing of the damaged portion, for state D4 (ST) . Their costs have been evaluated as a function of the damage state of the structural element, that is of the extension of the provided works. The data-base of costs allows to get the retrofitting costs of a structural element, C DS,j, for any values of the listed parameters. It has been found that the most significant control parameter is the cross section area of the element. Fig.1a reports the diagrams of retrofitting costs of columns as a function of the damage state for different cross section area. Fig.1b shows the diagrams of the retrofitting costs at the different damage state of columns as a function of the cross section areas, while assuming for the other parameters the default values. Once the retrofitting cost of each structural element has been defined as a function of its damage state and of its geometrical characteristics, the total cost of the structural damage results from the sum of the costs of the total number, n , of elements of the structure

n

1 = = å i

(1)

C

c

DS

, DS i

500 1000 1500 2000 2500 3000 3500 4000 4500

500 1000 1500 2000 2500 3000 3500 4000 4500

D1 D2 D3 D4

A =0,563 m 2

a

b

Retrofitting cost ( € )

Retrofitting cost ( € )

A =0,09 m 2

2 D2

1 D1

3 D3

D

4

0

0,1 0,2 0,3 0,4 0,5 0,6

Damage state

Area (m 2 )

Fig 1 (a) Retrofitting costs of columns as a function of the damage state for different cross section areas; (b) retrofitting costs of columns as a function of the cross section areas for different damage state 4. Damage states and consequences for non structural elements Claddings and partitions are characterized by three damage levels: "light damage" D1 (NS) ; "medium damage" D2 (NS) ; "serious damage" D3 (NS) . The damage states are defined correspondently to the actual damage levels experimentally evidenced in masonry panels, Morandi P. et al. (2018). The presence of fine cracking fixes the state D1 (NS) ; the presence of local wide cracks fixes the state D2 (NS) ; extensive presence of wide cracks with local crashing fixes the state D3 (NS) . Damage of non structural depends on the interstory drift ratio Δ r : the values Δ lim,D1 = 0.003, Δ lim,D2 = 0.010, Δ lim,D3 = 0.025, are the limit values of the interstory drift ratio corresponding to the three damage states D1 (NS) , D2 (NS) , D3 (NS) , respectively. The costs associated with non-structural elements derive by a market analysis and include, for damage states D2 (NS) and D3 (NS) , the cost of ancillary works concerning removal and resetting of fixtures and equipment. In particular the following retrofitting works have been considered: filling, smoothing and painting, for state D1 (NS) ; partial demolition