实践证明利用传统预应力锚索进行露天矿山滑坡灾害监测预警,当滑动力超过预应力锚索材料破断力时会发生锚索被拉断破坏的现象,从而导致整个监测系统失效。针对上述情况,一种具有负泊松比特性的高恒阻大变形滑坡监测锚索被研发出来,且广泛应用于露天矿山滑坡监测领域。首先描述了高恒阻滑坡监测锚索的结构组成;然后,建立了高恒阻力学模型,揭示了其大变形的工作机理;接着,通过一系列静力拉伸条件下力学特性室内试验,试验结果证明,高恒阻锚索拉伸时,可保持500 kN的恒阻力,最大延伸量可达850 mm,揭示高恒阻滑坡监测锚索在几何尺度与应变尺度上的负泊松比效应;最后,将该锚索应用于南芬露天铁矿边坡安全监测现场,成功对“2010-0731滑坡”全过程进行了监测预警,为其在类似工程中的应用提供了理论和实践依据。

Practice has proved that in using traditional pre-stressed cable for the monitoring and early warning of open-pit mine landslide, cables would fracture and result in failure of the whole monitoring system when sliding force is higher than the material strength of pre-stressed cables. In view of this, Prof. Manchao He developed a system of anchor cables with high constant resistance for monitoring large deformation. The system has been used in open-pit mine for landslide monitoring. In this paper, the effect of negative Poisson’s ratio of the cables is revealed in geometric and strain dimensions through indoor static tensile tests. The structure of the high constant-resistance cable is described, and the working mechanism of monitoring large deformation is analyzed by establishing a mechanics model of high constant resistance. Results manifest that the cable of high constant-resistance can be stretched to a maximum of 850 mm with a constant resistance of 500 kN. The cable has been applied to the safety monitoring of slope at Nanfen open-pit iron mine, and provided monitoring and early-warning for the landslide on 31^st July, 2010.