高陡边坡引导式落石防护网系统原位冲击试验

针对高陡边坡落石防护，提出了一种引导式落石防护网系统技术。通过落石运动路径全历程的动能特征分析，建立了系统的主动耗能控制方程，明确了防护系统的耗能控制原理，提出了防护技术措施，构建了引导式落石防护网系统的结构模型。设计了防护能量为2500kJ的足尺引导式柔性防护网系统模型，开展了场地冲击试验，系统试验模型铺设于破碎岩体发育的高陡坡面，铺设宽130m，高82m，纵坡约60°。考虑有、无防护系统，开展了6个落石冲击试验工况，对落石轨迹特征、冲击动能进行了对比分析。研究发现，与落石自然滚落相比，设置引导防护系统后，落石沿坡面的运动时间延长超80%，落石的碰撞次数增加约5倍，弹跳高度降幅超80%，横向偏移量降幅超50%，触底动能和坡底逸出距离均减少约65%，综合耗能比例高达89%，新系统实现了对落石崩塌灾害的“拦截 压制 引导”综合控制。

In-situ experiment of guided flexible protection system against rockfall on high and steep slope based on the active energy dissipating mechanism

A guided flexible protection system with active energy dissipation is proposed for rockfall protection on the high and steep slope. An equation for active energy dissipation control of the system is established, and the principle of energy dissipation control of the system is clarified, through the analysis of the kinetic energy characteristics of the whole rockfall motion path. Then the technical protection measures are put forward, and the structural model of the system is designed. The in-situ experiment is carried out on a high and steep slope with broken rocks. Test model with 2500kJ protection energy is 130m wide and 82m high, and the longitudinal slope is about 60°. Three kinds of impactors are released from the top of the slope in two conditions: with and without the system on the slope. Compared with the non-protected condition, the results of protected condition are quite positive: the falling time of the impactor extends by 80%; the number of collisions increases about 5 times; the maximum bounce height and lateral offset of the rockfall trajectory are decreased by 80% and 50%, respectively; both the residual kinetic energy and the escaping distance at the bottom of the slope are reduced by 65%; and the energy dissipation rate of the protection process is 89%. With the new system, the comprehensive control of “intercept-suppression-guidance” of rockfall collapse disaster can be achieved.