SEISMIC RESPONSES OF WEAK INTERLAYERED SLOPE WITH ANCHOR-FRAME REINFORCEMENT USING MODEL SLOPE ON SHAKING TABLE

This paper is based on the prototype slope with weak interlayer inclusion and anchor-frame reinforcement at the MK10+250 of Zhaoyin Expressway. A 1/30 downscale model slope is designed and shaking table tests with 20 loading cases are then conducted. The influences of slope elevation and seismic wave amplitude on the PGA amplification coefficient and the PEP oscillation coefficient are focused in this paper. The PGA amplification coefficients inside and upon the slope always increase with the slope elevation. Due to the isolation effect of weak interlayer and the reinforcement effect of anchor-frame, however, the acceleration response of slope tends to be entirety and no whiplash effect is presented. The PGA amplification coefficients decease linearly(at lower elevation) or exponentially(at upper elevation) with the amplitude of input seismic wave. The PEP oscillation coefficients inside the slop increase linearly with the cover depth, while increase non-linearly with the amplitude of input seismic wave. When excited by the seismic waves with larger amplitude, the additional horizontal pressure towards outside tends to be greater than the counterpart towards inside. The failure characteristic of model slope during shaking table tests is carefully inspected and described. The cracks concentrate in the upper part of slope above the weak interlayer, especially upon the top face of slope. However, no overall instability is presented along the weak interlayer due to the reinforcement effect of anchor-frame.