尾矿库溃坝对下游高速公路桥梁的损伤和滑动破坏评估  

Damage and Sliding Failure Assessment of Downstream Expressway Bridges Caused by Tailings Pond Dam Break

作　　者：邓金鹏 宋英华[1] 胡少华[1] 李墨潇[1] 周虹延 闫崭 DENG Jinpeng;SONG Yinghua;HU Shaohua;LI Moxiao;ZHOU Hongyan;YAN Zhan(School of Safety Science and Emergency Management,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学安全科学与应急管理学院,湖北武汉430070

出　　处：《金属矿山》2023年第12期220-226,共7页Metal Mine

基　　金：国家自然科学基金项目(编号:51979208);“十三五”国家重点研发计划项目(编号:2017YFC0804600);国家大坝安全工程技术研究中心开放基金项目(编号:CX2019B014)。

摘　　要：溃坝尾砂泥石流是介于水和一般自然界泥石流二者之间的一种颗粒相对均匀的砂—水混合物浆体,具有高势能、流速快的特性,易对下游高速公路造成巨大威胁,因此开展溃坝尾砂泥石流对下游高速公路的损伤评估,对于保障尾矿库下游高速公路安全具有重要意义。本研究基于尾矿库溃坝数值模拟并结合泥石流领域的损伤和滑动破坏研究,建立了溃坝尾砂泥石流对下游高速公路桥梁的损伤和滑动破坏评估模型。首先,进行尾矿库溃坝数值模拟确定高速公路桥墩前溃坝尾砂泥石流的流速和深度变化;然后,将流速和深度数值模拟结果代入计算公式对高速公路损伤和滑动破坏进行定量评估;最后得出评估结果。以铜山口尾矿库为例开展工程应用,研究结果表明:尾矿库溃坝后高速公路桥墩损伤满足要求,桥墩基础损伤评估中计算出局部冲刷最大深度为4.456 m,大于桥墩基础顶部距离地面的高度4 m,一部分桥墩基础将受到侵蚀破坏;桥梁滑动破坏评估中计算出桥墩抗滑动稳定性系数为1.02,低于规范限制1.2,高速公路桥梁存在横向滑动风险。Dam break tailings debris flow is a kind of sand-water mixture slurry with relatively uniform particles between water and natural debris flow,it has the characteristics of high potential energy and fast flow rate,it is easy to pose a great threat to the downstream highway,therefore,the damage assessment of dam-broken tailings debris flow on downstream expressway is carried out,it is of great significance to ensure the safety of the expressway downstream of the tailings pond.This study is based on the numerical simulation of tailings pond dam break and combined with the research of damage and sliding failure in the field of debris flow,the damage and sliding failure assessment model of the downstream expressway bridge caused by dam broken tailings debris flow is established.Firstly,the flow velocity and depth variation of tailings debris flow in front of expressway bridge pier are determined by numerical simulation of tailings dam break.Then,the numerical simulation results of velocity and depth are substituted into the calculation formula to quantitatively evaluate the damage and sliding failure of the highway.Finally,the evaluation results are obtained.Taking Tongshankou tailings pond as an example,the engineering application is carried out,the research results show that the damage of expressway pier after tailings pond dam break meets the requirement.The maximum depth of local erosion calculated in the damage assessment of pier foundation is 4.456 m,which is greater than 4 m height from the top of pier foundation to the ground,part of the pier foundation will be damaged by erosion.The stability coefficient of pier against sliding is 1.02,which is lower than the standard limit 1.2,the highway bridge has transverse sliding risk.

关 键 词：尾矿库溃坝 高速公路 溃坝尾砂泥石流 损伤 滑动 

分 类 号：TV144[水利工程—水力学及河流动力学]