PSI - Issue 78

Amirmahmoud Behzadi et al. / Procedia Structural Integrity 78 (2026) 513–520

516

Table 1. Vehicles categories assumed Category

n. of axles

Vehicle axles configuration

Cat. A Cat. B Cat. C Cat. D Cat. E Cat. F Cat. G Cat. H Cat. I Cat. L Cat. M Cat. N

2 3 3 4 4 5 5 5 5 6 6

(O-----O)

(O-----O + ---O---)

(O----OO)

(O-----O + -----OO)

n. 4 axles not belonging to CAT.D

(O-----O + --OOO) (O----OO + O-----O) (O----O--+--O---OO)

n. 5 axles not belonging to CAT. F, G, H

(O----O + ----OOOO)

n. 6 axles not belonging to CAT. L

At least 7 axles

≥7

3. Methodology For each bridge span length L, Monte Carlo simulations derive a sample of braking force magnitudes (sorted in ascending order). The total braking force for each convoy was calculated, constrained by the condition that the whole convoy length, including the vehicles' lengths and inter-vehicle distance, fits within the bridge span. In this research, assumed span lengths are 10,20,30,40, and 50m. Fig. 3 demonstrates an example of the instant of a braking event when vehicles are involved in braking where stands for convoy's total length, is the vehicle length, a is the Inter-Vehicle Distance, and and are gross mass and deceleration respectively. Regarding the deceleration of the vehicle involved in a braking event, three braking scenarios were evaluated, referring to different braking situations:

● Scenario 1 : All vehicle types (including light vehicles) brake hard. ● Scenario 2 : Only heavy vehicles brake hard (most conservative). ● Scenario 3 : Only the lead heavy vehicle brakes hard, others brake moderately.

Fig. 3. Example of a braking event.