预应力锚索加固高陡边坡机制探讨

预应力锚索加固边坡是提高边坡稳定性的重要手段。弄清预应力锚索加固边坡的机制对于指导边坡加固设计具有重要的理论意义。通过建立高陡边坡计算模型,不断提高边坡岩土体强度折减系数,得到了边坡坡脚位移及预应力锚索内力变化规律,并结合预应力锚索加固岩体应力分布规律,得到了有益的结论:(1)边坡岩土体强度折减系数超过边坡安全系数后,预应力锚索内力开始迅速增加,越靠近坡脚的预应力锚索,内力增加越明显,可以监测坡脚处锚索内力变化,评价边坡稳定状态;(2)对于高陡边坡,绝大部分预应力锚索并不能提高潜在滑动面上的压应力,不能提高滑动面的抗剪强度;(3)预应力锚索加固高陡边坡的主要机制在于限制边坡潜在滑动体的位移。

Discussion on mechanism of reinforcing high and steep slope with prestressed anchor cable

Prestressed anchor cable reinforcement is an important way to improve slope stability. Understanding the mechanism of reinforcement of slope by prestressed anchor cables is of great theoretical significance for guiding the design of slope reinforcement. Based on the calculation model of the high and steep slope, through continuously improving the strength reduction coefficient of rock and soil mass, we obtained the variation law of the displacement of slope foot and internal force of prestressed anchor cables. According to the stress distribution law of rock mass reinforced by prestressed anchor cables, some useful conclusions are drawn. When the strength reduction coefficient of rock and soil mass exceeds the safety factor of the slope, the internal force of prestressed anchor cables increases rapidly. The internal force is obvious when it is close to the foot of the slope. The change of internal force of anchor cables at the foot of slope can be monitored for evaluating the stability. For high and steep slopes, most of the prestressed anchor cables can not improve the compressive stress on the potential sliding surface and the shear strength of the sliding surface. The primary mechanism of the prestressed anchor cables to reinforce high and steep slopes is to control the displacement of the potential sliding body of the slope.