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基于大型振动台模型试验,研究了含倾斜强风化带及局部边坡场地在地震波作用下的动力响应特征,同时结合边际谱理论分析、土层内部应变和边坡位移规律,探究了场地内部的损伤发展过程。试验结果表明:模型加载El Centro地震波时,基岩和基覆内加速度放大系数随高程增加而增大,当加载地震波幅值大于0.33 g时,输入幅值越大,加速度放大越小;强风化带处加速度峰值削弱明显,加载幅值越大,削弱程度越大。模型加载3 Hz正弦波时,边际谱能量识别显示场地损伤从平台与局部边坡拐角下的强风化带开始,此后局部边坡底部强风化和平台中部下的强风化带出现损伤,平台与局部边坡拐角处强风化带的损伤逐渐与顶部损伤贯通;土层应变、坡面位移规律印证了场地损伤的发展过程;由破坏现象、边际谱损伤发展分析、土层应变及边坡位移规律可知,该含倾斜强风化带场地的破坏模式表现为拉裂–剪切–滑移以及拉裂–剪切–破碎2种破坏模式。
Based on the large-scale shaking table model test, the dynamic response characteristics of slopes with strong weathering belts and local slopes under seismic waves are studied. Combined with the analysis of the marginal spectrum theory, the internal strain and slope displacement in the soil, Damage development process. The experimental results show that when the model is loaded with El Centro seismic wave, the acceleration amplification factor in bedrock and basement increases with the increase of elevation. When the amplitude of seismic load is greater than 0.33 g, the larger the input amplitude, the smaller the acceleration amplification. Peak acceleration at the band weakened significantly, the greater the load amplitude, the greater the degree of weakening. When the model is loaded with 3 Hz sine wave, the marginal spectral energy identification shows that the site damage starts from the strong weathered zone at the corner of the platform and the local slope, and then the strong weathering at the bottom of the local slope and the strong weathered zone at the middle of the platform are damaged. The damage of strong weathering zone at the corner of slope gradually passes through with the top damage. The law of soil strain and slope displacement confirms the development of site damage. From the analysis of damage phenomenon, the analysis of marginal spectrum damage, the law of soil strain and slope displacement The failure modes of the site with strong oblique weathering show two kinds of failure modes, namely, the mode of pull-shear-slip and the mode of pull-crack-shear-fracture.