Bridge Scour Simulation in Live-bed Condition with Suspended Load

XIONG Wen, YAO Hao, C. S. CAP, YE Jian-shu

Abstract

Based on the Eulerian-Eulerian two-phase flow theory, the live-bed pier scour was carefully simulated with the consideration of suspended load. The riverbed variations were obtained using the non-equilibrium sediment transport model by calculating the mass exchange between the suspended load and traction load. By redeveloping a Computational Fluid Dynamics (CFD) software, i.e., ANSYS Fluent, the sediment transport rates and exchange flux between the suspended load and traction load were calculated using the shear stress of sediment and sediment concentration. By doing this, the riverbed boundary can be real-timely updated according to the calculated riverbed variations to conduct the live-bed scour simulation. The accuracy and rationality of the proposed simulation was fully verified by comparing with the classic theory and several experimental results from the viewpoints of the suspended load distribution, scour depth, and scour hole profile. The significant influence of the sediment concentration on the scour performance was finally proven by a parametric study. It can be concluded that using the live-bed scour models based on the two-phase flow theory should be very necessary for an accurate simulation.

 

 

Keywords: piers,  two-phase flow model,  suspended load,  live-bed scour,  computational fluid dynamics(CFD)


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References


DENG L, CAI С S. Applications of fiber optic sensors in civil engineering [J]. Structural Engineering & Mechanics, 2007, 25(5); 577-596.

HUNT E B. Monitoring scour critical bridges[R], Washington, DC: Transportation Research Board, National Research Council, 2009.

XIONG W. CAI С S, KONG X. Instrumentation design for bridge scour monitoring using fiber bragg grating sensors[J]. Applied Optics, 2012, 51(5): 547 — 557.

KATTELL J, ERIKSSON M. Bridge scour evaluation; screening, analysis, and countermeasures [R]. Washington, DC; US Forest Service, 1998:1 — 10.

WEI Yan-ji, YE Yin-can. 3D numerical modeling of flow and scour around short cylinder [J]. Chinese Journal of Hydrodynamics :A 2008, 23(6); 656 — 661. (In Chinese)

ZHU Zhi-wen, LIU Zhen-qing. Three-dimensional numerical simulation for local scour around cylindric bridge pier[J]. China Journal of Highway and Transport, 2011, 24(2) : 43 — 48. (In Chinese)

YE Zhen. 3D numerical simulation of turbulent flow and local scour around spur dikes[D]. Hangzhou: College of Civil Engineering and Architecture, Zhejiang University. 2007 ; 6 — 7. (In Chinese)

LIU Chun-rong, DENG Li-ying, HU HE Ao-de. Image measurement of the probability of sediment incipience under complex flow [J]. Journal of Hunan University: Natural Sciences, 2008, 35(3): 24 — 27. (In Chinese)

ZHOU Jian, DU Qiang, YU Shi-cai. Numerical simulation study on the experiments of the initiation of debris flow [J]. Journal of Hunan University: Natural Sciences, 2015, 42(9) ; 96—103. (In Chinese)

LING Jian ming, LIN Xiao-ping, ZHAO Hong-duo. Analysis of three-dimensional flow field and local scour of riverbed a-round cylindrical pier[J]. Journal of Tongji University: Natural Science, 2007, 35(5): 582 — 586. (In Chinese)

QIAN Ning, WAN Zhao-hui. Mechanics of sediment transport М]. Beijing: Science Press. 2003 : 306 — 320. (In Chinese)

MELVILLE В M. Local scour at bridge sites[D]. Auckland. New Zealand; School of Engineering, University of Auckland, 1075, 86-102


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