基于落石运动特性分析的拦石网设计理念

Design conception of safe net system based on analysis of motion trace of rockfall

危岩是我国山地一种主要地质灾害类型,拦石网是近年应用的一种落石柔性被动防护系统。当前研究一方面重拦石网系统本身,轻落石运动特性,缺少初始运动参数;另一方面落石运动研究成果没有同拦石网系统特点相结合。本文将落石运动简化为综合摩擦运动,进行了危岩威胁区域预测。将落石在坡面运动状态归结为跳跃、滚动和滑动,并以危岩起始运动速度作为初始速度,通过分段计算得到落石沿坡面的完整运动路径。最后,根据落石运动特性计算结果,结合拦石网系统特点,提出了拦石网基于落石特性计算布设的原则和方法。工程应用表明:同传统刚性被动防护系统相比,拦石网环境适应性好、施工影响小、造价低、工期短。

Perilous rock is one of main geologic disasters in mountain area of China. Safe net system is a passive control technique for rockfall in recent years. To study safe net system, on the one hand, much attention is paid to system itself without care of characters of rockfall trace and initial motional parameters. On the other hand, study of rockfall doesn＇t comply with the characters of safe net system. So, the authors simplified the motion of rockfall as equivalent frictional motion, and the imperilled area by rockfall was estimated. Additionally, by classifying the motion of rockfall on slope surface into intersected bouncing, rolling and sliding, the whole trace of rockfall was calculated. Finally based on the results of rockfall trace calculation combined with the characters of safe net system, the authors presented the conception and method of design of safe net system. Engineering application as wellas comparison with typical rigid passive control techniques showed that the safe net system had advantages of better applicability to engineering surroundings, less influence on environment, cheaper and shorter time limit for projects.