PSI - Issue 62

Mariano Angelo Zanini et al. / Procedia Structural Integrity 62 (2024) 815–823 Zanini / Structural Integrity Procedia 00 (2019) 000 – 000

819

5

determined in relation to bending beam stiffness ratios, load position and the beam transversal position. In order to compute the structural demand index defined as the maximum action in terms of bending moment and shear on the structural elements of the girder deck derived by the application of each of the abovementioned EV loading schemes divided by the same quantity computed with the load model used for the design of the deck, an overview on the evolution of the load models in the last century for the design of bridges in Italy has been carried out. In detail, the following regulations for the determination of traffic load schemes have been considered: - Ministry of Public Works (MPW), 1933. Normal n. 8; - Ministry of Public Works (MPW), 1945. Normal n. 6018; - Azienda Nazionale Autonoma delle Strade (ANAS), 1952. Circular n. 820; - Ministry of Public Works (MPW), 1962. Circular n. 384 – Standards relating to loads for the calculation of road bridges; - Ministry of Public Works (MPW), 1970. Circular n. 7091 of 04/11/1970 – Standards for the design of steel road bridges; - Ministry of Public Works (MPW), 1980. Ministerial Decree n. 308 of 02/08/1980 – General criteria and technical requirements for the design, construction and testing of road bridges; - Ministry of Public Works (MPW) 1990. Ministerial Decree of 04/05/1990 – Update of technical standards for the design, construction and testing of road bridges; - Ministry of Infrastructures and Transports (MIT), 2005. Ministerial Decree n. 222 o 14/09/2005 – Technical Standards for Construction; - Ministry of Infrastructures and Transports (MIT), 2008. Ministerial Decree n. 29 of 14/01/2008 – Update of the new Construction Regulations; - Ministry of Infrastructures and Transports (MIT), 2018. Ministerial Decree n. 8 of 17/01/2018 – Update of the new Construction Regulations; - Ministry of Infrastructures and Transports (MIT), 2019. Circular n. 7 of 17/01/2019 – Instructions for the application of the update of the new construction Standards referred to in the Ministerial Decree 17 January 2018. Traffic load models have been applied considering the worst disposition according to the regulations of each era, thus capturing the highest structural demand on the most solicitated element section. For the computation of the L3EV coefficient, a Matlab code has been set up, whose calculation flow is described in Fig. 3.

Fig. 3. L3EV calculation flow implemented in Matlab environment.

As regards the parametrization of the main input data, the following characteristics have been considered for the simply-supported girder deck configuration analyzed:

Span length (L): Deck width (W):

6 – 10 – 15 – 20 – 25 – 30 – 35 – 40 m;

• •

8 – 8.5 – 9 – 9.5 – 10 – 10.5 – 11 – 11.5 – 12 – 12.5 – 13 – 13.5 – 14 – 14.5 – 15 m;

• Number of beams (n b ): 3 – 4 – 5 – 6 – 7 - 8. thus leading to an overall number of 720 girder deck configurations.