铁路沿线层状碎裂结构岩质边坡动力响应特性振动台试验研究OA

To address the seismic stability of layered fractured rock slopes along railways in the rugged mountainous areas of Southwest China,three typical layered fractured slope models,namely horizontal,dip-slope,and anti-dip slope models,were established under a unified geometric similarity ratio,material parameters,and boundary conditions.Large-scale shaking table model tests were conducted to investigate the failure evolution,dynamic response,and damage identification characteristics of slopes with different structural types.The results show that the horizontal slope mainly exhibits a tensile-shear-sliding failure mode,the dip-slope presents a tensile-shear-uplift-sliding failure mode,and the anti-dip slope shows a bending-toppling failure mode.All three types of slopes exhibit elevation amplification and near-surface effects.The acceleration amplification effect of the horizontal and dip-slope models increases significantly above 100 cm,whereas the dynamic response of the anti-dip slope becomes more pronounced above 140 cm.With increasing input peak acceleration,the high-power dynamic response zone of the horizontal slope shifts downward from the slope shoulder after damage development;the overall response amplification effect of the dip-slope increases,while the response intensity in local damaged zones decreases;and the amplification effect of the anti-dip slope shows alternating fluctuations characterized by an initial decrease followed by an increase.When the input frequency of the sine wave increases from 5 Hz to 10 Hz,the acceleration amplification effect in the middle and upper parts of all three slopes is enhanced.Damage identification results based on the Hilbert-Huang Transform(HHT)and marginal spectrum show that energy anomalies in the horizontal slope first occur near the middle part of the slope surface and then develop toward the slope shoulder and lower-elevation areas;the slip surface of the dip-slope is mainly initiated inside the slope waist;and the slope shoulder of the anti-dip slope is the main vulnerable area under high-amplitude seismic input.The results provide an experimental basis for seismic stability evaluation and monitoring layout of layered fractured rock slopes.