Centrifuge modeling tests on seismic response of lower bedrock deposit slopes before and after reinforced with stabilizing piles
SUN Zhiliang,KONG Lingwei,GUO Aiguo
(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,
Chinese Academy of Sciences,Wuhan,Hubei 430071,China)
Abstract:In this research,two centrifuge shaking table model tests with the geometric scale of 1∶50 were conducted to study the seismic behaviours of lower bedrock deposit slopes before and after reinforced with stabilizing piles. 4-stage seismic waves(El Centro wave) with the increasing peak acceleration were applied from the bottom of each model. The acceleration response at slope surface and inside,the crest settlements,the distribution characteristics of static and dynamic bending moments were monitored in the process of tests. The recorded data and observations of the centrifuge models showed that the PGA amplification coefficient,the acceleration response spectra and the settlements at slope crest were decreased to some extent when the lower bedrock deposit slope was reinforced with the stabilizing piles. The stabilizing piles improved the seismic performance of upper deposit under earthquake conditions and in the meantime caused the seismic wave reflection effects in slope body,which make slope surface acceleration amplification factor increased along the pile-crest direction but decreased along the pile-toe direction. The relationships between the permanent displacements at slope crest and the Arias intensity of input seismic waves were linear. The changing amplitude of the dynamic bending moment of pile in the earthquake loading process was significantly larger than the increment of static bending moment after seismic excitations. Both the dynamic bending moment and static bending moment of pile reached their peak values near the bedrock surface,where the stabilizing piles most likely been damaged. These features should be fully considered in the aseismic design of stabilizing piles.
孙志亮,孔令伟,郭爱国. 下伏基岩堆积体边坡抗滑桩加固前后地震响应特征离心模型试验[J]. 岩石力学与工程学报, 2017, 36(6): 1413-1423.
SUN Zhiliang,KONG Lingwei,GUO Aiguo. Centrifuge modeling tests on seismic response of lower bedrock deposit slopes before and after reinforced with stabilizing piles. , 2017, 36(6): 1413-1423.