关键词: 自适应锚索, 岩质边坡, 地震响应, 模型试验, 动力安全系数

Abstract: At the instant of the occurrence of an earthquake, the conventional prestressed anchor cables tend to break due to the insufficient deformation ability suddenly. Once the failure of the anchor cable occurs, the safety of the entire anchorage structure is endangered. This study aims to investigate the seismic response of the adaptive anchor cables and the corresponding dynamic characteristics of the anchored slope. The experiments for the rock slope with adaptive anchor cables are conducted based on a new type of anti-seismic anchor cable as a prototype and accordingly loaded by the shaking table test system. In the experiments, four kinds of seismic waves are applied, such as sinusoidal wave, Tianjin wave, EI wave and Taft wave. The real-time strain of the cables and corresponding seismic response of the slope are monitored. The results show that the axial force of anchor cables is closely related to the amplitude, type, seismic excitation frequency of the seismic wave. The acceleration and displacement on slope surface are enlarged with different elevations, and the peak acceleration and displacement decrease compared to the rock slope without anchor cables. With different values of preset slipping constant resistance of adaptive anchor cables, the anchor cables produce three slip modes such as non-slip, instantaneous slip and gradual slip. The corresponding time history curves of cable strain and dynamic safety coefficient of the anchored slope are identically different. Under the condition of the cable slipping, the safety coefficient of the slope decreases partially, whereas the safety capacity of the anchored structure is large enough to suit for the large deformation and transient impact loads on the rock slope. Therefore, the experimental results provide references for the study on the roadway slope supporting and anti-seismic design of the adaptive anchor cables in the strong earthquake area.

Key words: adaptive anchor cable, rock slope, seismic response, model test, dynamic safety factor