桥梁基桩在含沙水流冲击作用下的冲蚀磨损数值模拟研究

Numerical simulation study on erosion and wear of bridge pile foundation under the impact of sandy water flow

过水桥梁的基桩外露已成为影响桥梁安全性的重要因素,携沙水流会对外露部分的基桩产生冲蚀作用,加速混凝土的破坏,累积到一定程度,会导致桥梁安全性降低,影响桥梁交通的正常运营。为研究携沙水流对基桩的冲蚀磨损规律及其影响因素,利用ANSYS-Workbench建立三维模型,在FLUENT的工作环境下,模拟水沙两相流的流动特性,并求解得出基桩最大冲蚀磨损速率。通过数值模拟,研究了携沙水流的流场特性,并得出了在不同流速、含沙量及粒径下的冲蚀磨损规律。结果表明:流速、含沙量及粒径都对最大冲蚀率有较大影响,其中,最大冲蚀率随流速的增加而增大,并呈现出明显的指数关系;含沙量与最大冲蚀率呈现出正相关关系;最大冲蚀率随粒径的增大呈现出先减少后趋于稳定的趋势。研究成果可以为后续基桩冲蚀磨损预测的工程应用提供相关依据。

The exposure of foundation piles of bridges over water has become an important factor affecting the safety of the bridge. The sand-carrying water flow will cause erosion of the exposed part of the foundation piles, accelerate the destruction of concrete, and accumulate to a certain degree, which will reduce the safety of the bridge. The normal operation of bridge traffic. In order to study the erosion and wear law of sand-carrying water flow on foundation piles and its influencing factors, a three-dimensional model was established using ANSYS-Workbench. Under the working environment of FLUENT, the flow characteristics of water and sand two-phase flow were simulated, and the maximum value of foundation piles was obtained. Erosive wear rate. Through numerical simulation, the flow field characteristics of the sand-carrying water flow are studied, and the erosion and abrasion laws under different flow velocity, sand content and particle size are obtained. The results show that flow velocity, sand content, and particle size all have a greater impact on the maximum erosion rate. Among them, the maximum erosion rate increases with the increase in flow velocity, and shows an obvious exponential relationship;the sediment content and the maximum erosion rate The erosion rate shows a positive correlation;the maximum erosion rate shows a trend of first decreasing and then becoming stable with the increase of particle size. The research results can provide relevant basis for the subsequent engineering application of foundation pile erosion and wear prediction.