基于桩群的堤防溃口流场阵列效应数值模拟研究OA

[Objective]The study reveals the influence mechanisms of three pile group arrangements-no piles,plum blossom-shaped,and rectangular-on the array effects of breach flow fields and their hydrodynamic characteristics,aiming to provide a theoretical basis for optimizing pile group layouts in dike breach emergency response.[Methods]A three-dimensional dike breach model was established using FLOW-3D software to simulate the evolution of breach flow patterns under the three pile group arrangements.The influence of pile groups on breach hydrodynamics was systematically evaluated.[Results](1)Pile group arrangements significantly reduced flow velocities in the breach and floodplain areas while optimizing flow field distribu-tion.(2)Compared to the no-pile condition,pile group arrangements decreased the maximum breach flow velocity from 2.305 m/s to 2.094-2.185 m/s,resulting in reductions of approximately 5.21%-9.15%.The mainstream velocity in the floodplain area decreased from 2.880 m/s to 2.182-2.840 m/s,resulting in reductions of approximately 1.39%-24.24%.(3)The water depth distribution pattern in the breach zone under the three layouts was as follows:in the no-pile and plum blossom-shaped layouts,water depth at the breach gradually decreased along the flow direction;in the rectangular arrange-ment,water depth at the breach was higher at the front and rear sides and lower in the center,forming a triangular high-water-depth zone in the downstream floodplain.(4)The rectangular arrangement demonstrated the most effective flow attenuation,followed by the plum blossom-shaped arrangement,whose velocity variation pattern resembled that of the no-pile arrangement.The flow pattern at the breach under the plum blossom-shaped arrangement was smoother than that under the no-pile arrange-ment.The rectangular arrangement proved superior in mitigating hydraulic forces and improving breach flow patterns.Its tri-angular high-water-depth zone effectively reduced flow impact,enhancing protection of downstream floodplain areas.[Conclusion]The hydrodynamic regulation advantages of different pile group layouts vary,with the rectangular arrangement demonstrating the most comprehensive effectiveness in flow velocity reduction and flow pattern improvement.This study pro-vides a scientific basis for optimizing pile group design in rapid breach closure projects,holding significant practical insights for enhancing emergency response efficiency and flood disaster management capabilities.