中文摘要：

有在运动的岩石块的大群众的山危险 -- 例如岩石下降，雪崩和山崩威胁，人生活并且组织。动态破碎在在岩石雪崩的岩石块的运动过程期间是普通现象，由于对阻塞的高速度和影响。鉴于为易碎的岩石的精力消费理论，破碎由邦德求婚了，它联系精力缩放减小，当它对阻塞影响时，一个理论模型被建议为动人的岩石块估计平均碎片尺寸。然后，运动的不同形式被学习，与为动人的岩石块的各种各样的落下高度和斜坡角度。当落下高度增加，计算结果表明平均碎片缩放减少，是否为免费秋天或为低高度为在尺寸的滑动或滚动的岩石块，和衰落是快速的并且为在相应曲线增加高度变慢。而且，当斜坡角度为滑动岩石块增加，平均碎片尺寸也减少。另外，滚动岩石块比滑动岩石块有破碎的更高的度，甚至为一样的斜坡角度和块体积。最后，结果与其它作比较，碎片的近似数字为每个计算例子，和建议模型对相对各向同性的移动岩石块适用的结果表演被估计。

英文摘要：

Mountain hazards with large masses of rock blocks in motion – such as rock falls, avalanches and landslides – threaten human lives and structures. Dynamic fragmentation is a common phenomenon during the movement process of rock blocks in rock avalanche, due to the high velocity and impacts against obstructions. In view of the energy consumption theory for brittle rock fragmentation proposed by Bond, which relates energy to size reduction, a theoretical model is proposed to estimate the average fragment size for a moving rock block when it impacts against an obstruction. Then, different forms of motion are studied, with various drop heights and slope angles for the moving rock block. The calculated results reveal that the average fragment size decreases as the drop height increases, whether for free-fall or for a sliding or rolling rock block, and the decline in size is rapid for low heights and slow for increasing heights in the corresponding curves. Moreover, the average fragment size also decreases as the slope angle increases for a slidingrock block. In addition, a rolling rock block has a higher degree of fragmentation than a sliding rock block, even for the same slope angle and block volume. Finally, to compare with others＇ results, the approximate number of fragments is estimated for each calculated example, and the results show that the proposed model is applicable to a relatively isotropic moving rock block.