山崖地震飞石的地震动力学特征试验研究

“5·12”汶川地震诱发了众多崩塌和滑坡等次生地质灾害，地震飞石是一种较为常见的特殊地震现象。为了探究地震飞石蕴含的地震动力学特征，利用弹射模拟试验与PIV高速成像技术，研究了不同弹射力下岩体材料、重量和形状等参数对山崖危岩从脱离母岩抛射到飞跃落定整个过程的影响。结果表明:弹射力越大，质量越小，等效半径越大，块体抛射初动能越大；通过分析抛射角对抛射初动能的影响，得出0°对应的抛射初速度公式，并建议抛射角大于15°时系数值取1.52，小于-15°时取2.89，其他角度线性内插；结合理论分析与试验研究间接求出地震动加速度，并通过映秀飞石的计算得到验证。

Experimental Study on Seismic Dynamical Characteristics of Cliff Earthquake Slungshot

‘5·12 Wenchuan’ Great Earthquake induced many secondary disasters like collapses and landslides, and earthquake slungshot is the most common special seismism. To understand the seismic dynamic characteristics of the earthquake slungshot, the ejection simulation experiment and PIV high-speed imaging technology are used to study the impact of such parameters of rock mass as material, weight, shape, etc., on the whole process form separation of the dangerous cliff rock from the mother rock to falling to the ground. The experimental results show that the greater the catapulting force is, the lower the mass is, the larger equivalent radius, the greater initial kinetic energy the slungshot has. The formula of initial throwing velocity corresponding to 0° is obtained by analyzing the impact of projection angle on initial dynamical, and it is recommended to select coefficient 1.52 when the projection angle is more than 15°, 2.89 when it is less than -15° and linear interpolation is applicable for other angles. The earthquake ground motion acceleration is calculated by theoretical analysis and experimental study and verified by sungshot in Yingxiu.