振动台对尾矿砂振动性能试验研究

Shaking Table Test on Vibration Properties of Tailings Sand

经过室内基本物性试验确定尾矿库堆坝材料的物性指标。在此基础上使用机械式振动试验台对尾矿砂振动性能进行研究。通过改变尾矿砂含水率和调整振动台振幅的方法,观察不同含水率下尾矿砂密度变化与振幅的关系,探讨尾矿砂出现振动液化现象的临界含水率,总结尾矿砂在出现涌水现象后发生的破坏形式,同时记录下引起尾矿砂密度变化和液化破坏的振动速度值。研究表明:尾矿砂中出现液化的含水率临界值是16.65%,该含水率下尾矿砂出现振动液化现象的振动速度值是28.68 cm/s。含水率为17.56%的尾矿砂出现振动液化现象的振动速度值是27.1 cm/s。尾矿砂出现涌水现象后会伴随冒砂现象的发生,并且加剧砂土表层开裂,甚至出现塌陷,导致砂体的结构遭到破坏,稳定性变差。

The typical heap dam material properties indicators were confirmed by laboratory experiment. The me-chanical shaking table was used to study the vibration properties of the tailings sand. By changing the tailings sand moisture content and the amplitude of the shaking table,the relationship of tailings sand density variation and ampli-tude under the condition of different moisture content was observed;the critical moisture content of tailings sand was discussed;the phenomena of vibration liquefaction and the damage forms of tailings sand after water gushing were al-so explored and summarized. Meanwhile,the vibration velocity influencing tailings sand density and liquefied destruc-tion changing was recorded. The studies show that the threshold of tailings sand liquefying was 16. 65%,where the liquefaction vibration velocity was 28. 68 cm/s. On the condition of moisture content 17. 56%,the sand liquefaction vibration velocity was 27. 1 cm/s. Water gushing phenomenon was accompanied with the tailings sand eruption,which exacerbated the sand surface crack and collapse,body structure destruction and disability.