常规面板堆石坝坝前水下防爆距离的确定和影响因素

Underwater explosion protection range of conventional concrete face rockfill dam and its influencing factors

鉴于混凝土面板堆石坝较弱的抗爆性能,确定合理的坝前水下防爆距离,为坝前水下反恐安全防护设计和预警监测范围提供参考是必要的。选取常规100 m级高的面板堆石坝作为分析对象,借助有限元程序Abaqus/Explic-it,采用声学介质描述库水,采用大坝-地基-库水系统有限元模型,主要考虑坝前不同距离发生10 kg TNT当量水下爆炸,研究混凝土面板的损伤破坏情况及其影响因素。计算结果表明:堆石体变形模量Er、面板竖缝和周边缝摩擦系数fj、面板与堆石体之间摩擦系数fb等三个参数在常规范围内取值不会对最终面板破坏的预测产生质的影响。得到结论:坝前水下防爆距离Dp定为200 m是合适的。

In view of the weak knock resistance of concrete face rockfill dam （ CFRD）, it is essential to determine a rational underwater explosion protection range in front of a dam in the design of anti-terrorism safety protection, underwater monitoring and prewarning. A conventional 100 m-high CFRD was analyzed using Abaqus/Explicit finite element analysis software. The structural damage and the failure of concrete face and their influencing factors were focused on. The dam-foundation-water interaction was considered and the water was simulated using acoustic element. Several explosive distances were supposed with a 10 kg-TNT charge underwater explosion in front of the dam. The result shows that different conventional assignments of the three parameters including rockfill＇s deformation modulus Er, friction factor of vertical and peripheral joints fj and friction factor of contact between concrete face and rockfill fb do not exert an essential influence on the prediction of concrete face＇s structural failure. It is concluded that the rational underwater explosion protection distance Dp in front of the dam should be determined as 200 m.