TY - JOUR PY - 2017// TI - A framework for probabilistic assessment of clear-water scour around bridge piers JO - Structural safety A1 - Tubaldi, Enrico A1 - Macorini, Lorenzo A1 - Izzuddin, Bassam A. A1 - Manes, Costantino A1 - Laio, Francesco SP - 11 EP - 22 VL - 69 IS - N2 - Scouring at the base of bridge piers is the major cause of bridge collapses worldwide. Computing the scour risk of bridge foundations is therefore key for a correct management and allocation of resources for maintenance and scour mitigation works. Existing risk-assessment models compute the vulnerability of bridge foundations to scour by comparing the equilibrium scour depth associated with peak-flow discharges characterized by a given return period (usually of 100-200years) with the critical foundation depth of the bridge. This approach neglects completely the history-dependent and time-dependent nature of scour. Yet, it is well known that bridge collapses can often be induced by the accumulation of scour during multiple flood events. This study aims at developing a novel probabilistic framework for the computation of bridge-pier vulnerability to scour using a Markovian approach to account for memory effects in scour development. The paper focuses on the case of local pier scour occurring in clear-water conditions whereby cumulative effects are significant, well understood and known to be the cause of recent reported bridge collapses. A simplified numerical example consisting of an idealised bridge pier in a canal is considered to clarify the application of the proposed framework and to shed light on the effects of some assumptions introduced to simplify the probabilistic scour assessment.
Language: en
LA - en SN - 0167-4730 UR - http://dx.doi.org/10.1016/j.strusafe.2017.07.001 ID - ref1 ER -