关键词: 预应力锚索, 边坡, 地震, Newmark法

Abstract: Stability analysis is of great significance to the safety of slope engineering. In order to study the influence of seismic loads on slopes strengthened by prestressed anchor cables, firstly, the staged model of slope stability under seismic loads is analyzed based on the safety reserve characteristics of prestressed anchor cable, and secondly, the formulas of displacement, anchoring force and safety factor of bedding rock slope are derived by using the traditional Newmark’s displacement calculation method. At last, two examples are used to study the displacement behavior of prestressed slope under different cable models and seismic accumulations. It can be seen from the results that when the anchoring force is taken as a constant value, the calculated seismic slope displacement is larger and increases linearly with time. When considering the safety reserves of anchor cables, the growth rate of displacement gradually decreases with time and finally reaches a constant value. Different cable models have great influence on the calculated displacement, and the reserve effect of cable cannot be ignored. Seismic loads, meanwhile, have a permanent effect on the prestressed anchor slope. The critical threshold of slope sliding increases if the slope is re-disturbed seismically. Displacement growth rate is inversely exponential with the acceleration intensity of the last shaking. Finally, taking the slope of an open pit mining area as a case study, the optimum supporting scheme is determined under the seismic fortification standard.

Key words: prestressed anchor cable, slope stability, seismic loads, Newmark method