| 泥石流对桥墩冲击力的试验研究 |
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| 引用本文： | 王友彪,姚昌荣,刘赛智,李亚东,张迅.泥石流对桥墩冲击力的试验研究[J].岩土力学,2019,40(2):616-623. |
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| 作者姓名： | 王友彪 姚昌荣 刘赛智 李亚东 张迅 |
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| 作者单位： | 西南交通大学 土木工程学院，四川 成都 610031 |
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| 基金项目： | 国家自然科学基金（No. 51478400）；四川省科技计划项目（No. 2016HH0076）。 |
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| 摘 要： | 泥石流冲毁桥墩是桥梁在遭受泥石流冲击时的常见破坏形式。为了研究泥石流对桥墩的冲击力大小，通过调整黏土、沙、石子、水的不同含量，配置不同流变特性、不同密度的泥石流，使用所配置的原料在泥石流槽内对两种形状（圆形、方形）的桥墩缩尺模型进行冲击，综合考察了流变特性、流速、桥墩形状以及冲击力的关系。试验表明：试验配置的泥石流原料流变特性差异明显，且可以用简单的选择流变仪测得，用牛顿流体或宾汉体描述。泥石流的流速可用曼宁公式求得，而公式中的糙率系数与泥石流黏度满足幂函数关系。相同工况下，不同形状桥墩所受的冲击力差异明显，方形桥墩阻力系数普遍大于圆形桥墩。使用非牛顿流体雷诺数（Re）可以综合反映流变特性和流速，因此，圆墩的阻力系数可表达为Re的函数，而方墩则没有明显关系。为方便工程应用，可根据黏性泥石流、稀性泥石流对圆墩的阻力系数分别为2.3、0.9，对方墩分别为2.6、1.9进行选用。
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| 关 键 词： | 泥石流 桥墩 冲击力 缩尺试验 |
| 收稿时间： | 2017-07-27 |
Experimental study of debris flow impact forces on bridge piers |
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| WANG You-biao,YAO Chang-rong,LIU Sai-zhi,LI Ya-dong,ZHANG Xun.Experimental study of debris flow impact forces on bridge piers[J].Rock and Soil Mechanics,2019,40(2):616-623. |
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| Authors: | WANG You-biao YAO Chang-rong LIU Sai-zhi LI Ya-dong ZHANG Xun |
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| Institution: | School of Civil Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China |
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| Abstract: | Debris flow destroying piers is a common destructive form of bridge under the impact of debris flow. To investigate the magnitude of debris flow impact forces on bridge piers, we adjusted the contents of clay, sand, gravel, and water to generate debris flows with different rheological properties and densities. Two types of pier scale models with circular and square cross section were impacted in debris flow trough by using the above debris flows to comprehensively investigate the relationship between rheological characteristics, flow velocity, pier shape and impact force. The results show that the obtained debris flow materials have distinct rheological properties which can be easily measured through a rotational viscometer and represented by Newtonian fluid or Bingham fluid. The velocity of debris flow can be calculated by the Manning equation, and the roughness coefficient and the viscosity of debris flow in the equation satisfy a power function relationship. In the same cases, the impact forces on a round pier and on a square pier are significantly different. Generally, the drag coefficient of impact force on a round pier is much larger than that on a square pier. Because using non-Newtonian fluid Reynolds number (Re) can comprehensively represent the debris flow’s rheological properties and velocities, the drag coefficient of the round pier be expressed as a function of Re. However, there exists this function for the square pier. For the convenient application in engineering, the drag coefficient of a round pier can be selected as 2.3 and 0.9 for viscous debris flow and sub-viscous debris flow, respectively. For a round pier, the drag coefficients are 2.6 and 1.9 for viscous debris flow and sub-viscous debris flow, respectively. |
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| Keywords: | debris flow bridge pier impact force scale model test |
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