رفتار سازه‌اي پل‌هاي چند‌دهانه‌ي قوسي‌آجري ايراني در برابر آبشستگي

This thesis investigates the structural behaviour of Persian brick arch bridges under various scour conditions. For the arch span cross-section shapes, semi-circular, four-centred, an‎d pointed arches have been employed. Each of these arches has been eva‎luated in three types: dro‎p, ordinary, an‎d raised. The different scour scenarios studied for a single pier include the central an‎d side piers, an‎d for two piers, the two central piers as well as one side pier an‎d one central pier. Those scenarios exhibiting the most an‎d least favourable performance under uniform line an‎d surface loads have been selec‎ted for further analysis under gravity loading for different ratios of geometric parameters, including: pier thickNess to arch span length at values of 0.10, 0.60, an‎d 0.80; bridge width to arch span length at 0.75, 1, an‎d 1.25; pier height to arch span length at 0.75, 1, an‎d 1.25; an‎d deck thickNess to arch span length at 0.25, 0.33, an‎d 0.5, as well as settlement an‎d seismic loading. The studied samples have been analysed under four types of loading: uniform distributed load, line load at the mid-span with scoured piers, pier settlement, an‎d seismic loading. Nonlinear analyses were conducted using the finite element software ANSYS, with the Willam-Warnke failure criterion employed to simulate the behaviour of brick materials. The results of the uniform surface loading indicate that, in most scour conditions involving a single central pier, the load-carrying capacity is greater than that of a bridge with scour at a single side pier. Moreover, the two-pier scour condition shows weaker performance compared to a single-pier scour. Under line loading at the apex of the arch span, no significant differences were observed in any scour models. Regarding uniform surface loading, structures featuring dro‎p four-centred arches at the bridge span demonstrate a significantly higher load capacity compared to semi-circular an‎d pointed arches. For line loading at the apex with scouring of the central pier(s), the raised pointed arch exhibits the highest load-carrying capacity, while dro‎p four-centred an‎d semi-circular arches have the lowest load-bearing capacities. Regarding pier settlement, settlement of a single side pier yielded better performance than other conditions, whereas settlement of a central pier resulted in the poorest outcome. Additionally, seismic performance analysis revealed that semi-circular an‎d four-centred arches possess greater earthquake resistance compared to pointed arches. Overall, in bridges with symmetric geometry an‎d pier scour, structural behaviour was satisfactory across all loading conditions.

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سعيد صرامي

146870