Reliability-based evaluation of scour around dual bridge piers

Abstract

The causes of uncertainty involved in temporal variation of the depth of cavern formation due to clear water scouring at dual piers with tandem arrangement are identified in this study. In an example, the probability of failure induced by scouring around dual piers is estimated for various pier spacing using probabilistic analysis. The effects of changes in the coefficient of variation of probabilistic scouring variables and probability distributions on the probability of the loss of stability, are also investigated. It was established that the effects of variations in the coefficient of variation on the probability of the loss of stability are more significant compared to that on the probability distributions of the scour depth. Key words: bridge, pier, probability of the loss of stability, scour, tandem arrangement, uncertainty Prethodno priopćenje Meric Yilmaz, Melih Calamak, A. Melih YanmazOcjena podlokavanja oko dvojnih stupova mosta primjenom analize pouzdanosti U ovom se istraživanju određuju uzroci nepouzdanosti uslijed vremenske varijacije dubine kaverne nastale podlokavanjem u uvjetima bistre vode na mjestu dvojnih stupova tandemskog razmještaja. Na primjeru se probabilističkom analizom ocjenjuje vjerojatnost gubitka stabilnosti uslijed podlokavanja oko dvojnih stupova, za razne razmake stupova. Istraženi su i utjecaji promjene koeficijenta varijacije probabilističkih varijabli podlokavanja, te funkcije razdiobe vjerojatnosti, na vjerojatnost gubitka stabilnosti. Utvrđeno je da su utjecaji promjene koeficijenta varijacije na vjerojatnost gubitka stabilnosti značajniji od razdiobe vjerojatnosti dubine podlokavanja. Ključne riječi: most, stup, vjerojatnost gubitka stabilnosti, podlokavanje, tandemski razmještaj, nepouzdanost Vorherige Mitteilung Meric Yilmaz, Melih Calamak, A. Melih Yanmaz Beurteilung der Unterspülung um die Doppelpfeiler einer Brücke anhand einer Zuverlässigkeitsanalyse In dieser Studie werden die Ursachen für die Unzuverlässigkeit durch die zeitliche Variation der Tiefe der Kaverne bestimmt, die durch Unterspülung mit klaren Wasserbedingungen am Standort von Doppelpfeilern in Tandemanordnung erzeugt wird. Am Beispiel wird mittels der probabilistischen Analyse die Wahrscheinlichkeit eines Stabilitätsverlusts aufgrund der Unterspülung von Doppelpfeilern mit unterschiedlichen Säulenabständen bewertet. Die Auswirkungen der Änderung des Variationskoeffizienten probabilistischer Variablen der Unterspülung sowie der Wahrscheinlichkeitsverteilungsfunktion auf die Wahrscheinlichkeit eines Stabilitätsverlusts wurden ebenfalls untersucht. Es wurde festgestellt, dass die Auswirkungen der Änderung des Variationskoeffizienten auf die Wahrscheinlichkeit eines Stabilitätsverlusts signifikanter waren als die Wahrscheinlichkeitsverteilung der Unterspülungstiefe.

Assessing the suitability of bridge-scour-monitoring devices

“…There are numerous studies which review various empirical and semi-empirical approaches for prediction of key scour related parameters e.g., scour depth (e.g., NASEM 2011; Briaud et al 2015aBriaud et al , 2015bBanks et al 2016;Aje & Khattab 2017;Saha et al 2018;Helal et al 2019;Yilmaz et al 2019).…”