Numerical simulation of scour around successive bridge piers with different shapes and different angles of placement relative to the flow direction

نوع: Type: Thesis

مقطع: Segment: masters

عنوان: Title: Numerical simulation of scour around successive bridge piers with different shapes and different angles of placement relative to the flow direction

ارائه دهنده: Provider: zahra kiani

اساتید راهنما: Supervisors: Dr. Majid Fazli

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Dr. Bahram Rezaei - Dr. Morteza Shokri

زمان و تاریخ ارائه: Time and date of presentation: 2026

مکان ارائه: Place of presentation: 43

چکیده: Abstract: Bridges are critical infrastructure structures in the transportation system. Engineers, relying on long-term experience in building river bridges, have concluded in recent decades that, in addition to structural considerations, geology, road location, and traffic capacity, it is essential to pay attention to the effects of water flow in bridge design. Bridge construction is an important and costly issue, and given that it requires a large investment, special attention should be paid to the serious risk of bridge failure, which occurs mostly due to scour. Scour at bridge piers is one of the key and determining factors in the hydraulic design of bridges. When a hydraulic structure such as a bridge pier is placed in the path of water flow, a three-dimensional flow is created around and behind the pier. Over time, this flow leads to the creation of a hole around the bridge pier. A large number of hydraulics researchers have conducted experimental studies and have measured and evaluated the scour rate for bridge piers of various dimensions, shapes, and combinations. Numerical modeling using software has a significant similarity to conducting practical experiments. Just as the results of an experiment are reliable if its conditions are as close to reality as possible, in numerical modeling the quality and validity of the results depend heavily on the input data; that is, if the data entered into the model is inappropriate, the results obtained will not be reliable. The Flow-3D numerical model is a computational fluid dynamics (CFD) and sediment model that has been used in scour problems. In this study, scour around bridge piers with different shapes and numbers was numerically simulated using Flow-3D software. Comparison of the results of different turbulence models with experimental results for a single circular bridge pier showed that the LES turbulence model provides better results. Next, the results of the numerical model were compared with the experimental results for single rectangular and hexagonal bridge piers. The comparison of the results showed that the numerical model provides better results in estimating the scour rate for rectangular piers. In order to calibrate the numerical model, simulations were performed for double and triple bridge piers with rectangular and hexago