关键词: 锚索, 预应力损失, 协同工作, 抗滑桩, 抗震设计

Abstract: A large-scale shaking table model test is designed to study the dynamic behaviors of slope reinforced by multi-frame foundation beam with anchor cable and double-row anti-slide piles under seismic loading. Several critical parameters are monitored during the test, including axial force of pre-stressed anchor cable, earth pressure on piles, acceleration of slope body and displacement-time relationship of slope surface. Experimental results show that the pre-stressing of anchor cable varies with input seismic wave, and its maximum value of pre-stress loss reaches 23% when input wave is El Centro seismic wave with an amplitude of 0.15g. The test results suggest that the applied pre-stress value should be risen up to 1.2 to 1.3 times of the designed value for reinforced slope with strict deflection limit. The axial forces of anchor cables installed at different altitudes reach the maximum almost simultaneously, but the increase proportion of peak axial force demonstrates non-uniformity in space, so the aseismic design of anchor cable should be divided into upper and lower sections with anti-slide piles installed in the middle section of the slope. The earth pressure increases with the amplitude of input seismic waves. As the amplitude increases, the distribution of active earth pressure changes from ‘upper small-lower big shape’ to ‘upper big-lower small shape’. The demarcation line between the passive earth pressure zones I and II shifts to the bottom of pile. Anchor cables and anti-slide piles should perform as a collaborative structure under earthquake, so the effect of earthquake on the sliding force sharing ratio between pile and anchor cable should be carefully considered. The results can provide references for the design of anchor cable frame beam and anti-slide pile supporting structure in earthquake zone.

Key words: anchor cable, prestress loss, cooperative work mechanism, anti-slide pile, aseismic design