| 曹帅,刘磊,张红武,张倩.基于随机过程的多沙河流河道内塔基局部冲刷研究[J].水利学报,2025,56(8):1025-1036 |
| 基于随机过程的多沙河流河道内塔基局部冲刷研究 |
| Research on local scour depth of tower foundation in sediment-laden rivers based on stochastic process |
| 投稿时间：2024-12-05 修订日期：2025-07-04 |
| DOI：10.13243/j.cnki.slxb.20240789 |
| 中文关键词: 随机过程 多沙河流 河内塔基 局部冲刷 模型试验 |
| 英文关键词: stochastic process sediment-laden river tower foundation local scour depth physical modeling experiment |
| 基金项目:国家重点研发计划项目（2016YFC0402500）；国家自然科学基金青年科学基金项目（52009145）；鄂尔多斯水利科技重点项目（20232000090） |
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| 中文摘要: |
| 河道输电跨越工程塔基的局部冲刷尚无统一计算方法，通常借鉴桥墩冲刷进行设计，但二者的冲刷机制与冲刷形态不同，计算结果往往与实际有较大偏差，尤其对于多沙河流并不适用。考虑塔基冲刷过程中作用在周围泥沙颗粒上的力是不确定的，故冲刷坑内各颗粒的运动位置也是随机的，从而在冲刷坑内部形成了一个马尔可夫随机运动场。本文基于泥沙运动和统计理论，分析塔基周围的冲刷形态、泥沙颗粒位置状态和转移概率，根据柯尔莫哥洛夫前进方程推导出颗粒位置状态的平均动力方程组，从而求解得到塔基局部冲刷深度的解析表达式；进一步对塔基冲刷机理进行分析，从时均位置状态转移概率密度的物理意义给出其函数表达式，并根据天然多沙河流实测统计资料及物理模型试验数据，初步确定了解析式中有关参数的取值；最后，通过两组冲刷模型试验对所提出的塔基局部冲刷深度解析式进行验证，结果显示计算值与实测值吻合较好。因此，基于随机过程对塔基局部冲刷进行研究是一种可行的方法，所推求的专用理论计算公式也可作为塔基工程中埋深设计的参考依据。 |
| 英文摘要: |
| The problem considered in this study is the local scour depth of transmission tower foundations，for which there is not yet unified calculation method in the sediment-laden rivers. Due to these problems，they are usually calculated by the formula of bridge pier scour at present，which lead to significant deviations with the actual results， especially in sediment-laden river like the Yellow River. In order to reduce the potential natural hazards caused by inaccurate calculations，this study has established a theoretical formula for the local scour depth of tower foundation based on the fundamentals of stochastic process. As the forces acting on the sediment particle are uncertain during the process of scouring around the tower foundation，the motion of each particle in the scour pit is also random，thus forming a stochastic sediment motion field within the scour influence range. According to the sediment transport theory，there are specific transport laws for both bed-load and suspended-load on the riverbed near the tower foundation. These laws provide the theoretical basis for determining the probability density of positional state transition based on Markov random field and the statistical theory of sediment movement. The scour pattern of the tower foundation，positional state model，and transfer-probability are discussed，and then the analytical formula for local scour depth is obtained by deriving the average dynamical equations of positional state. Meanwhile，by analyzing the physical mechanism of transition probability density，this study has determined the expression structures for the probability density functions of time-averaged positional state transition. In light of the measured statistical data from natural sediment-laden rivers and physical modeling experiments，the relevant parameters in the calculation formula for local scour depth of tower foundation have been preliminarily determined. Finally，two sets of tower foundation scour model tests can be used as evidence to verify the proposed analytical formula for local scour depth，and the result indicates that the calculated values are consistent with the actual measurements. |
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