Abstract:Slope dynamic response to an earthquake is a product of interaction between seismic waves of complex frequencies and slope body;different frequency components induce different slope responses. Through shaking table tests,effect of wave frequency on two model slopes is analyzed. The two model slopes are composed of the same materials of high strength,but different structures,isotropic and layered. Firstly,dynamic characteristics of model slopes calculated through excitations of white noises show that,resonance frequency of each model decreases and the internal structure becomes loose as the test is going on;and the first resonance frequency of horizontal component acceleration is larger than that of vertical component acceleration. Then,emphasis is put on the slope acceleration responses and their correlations with changing frequencies. Results show that:(1) Obvious topographic amplification occurs in relative elevation h/H>1/2 for horizontal component acceleration;while topographic amplification occurs in relative elevation h/H<3/4 for vertical component acceleration;and the phenomena are independent of the excitation frequency. (2) Under the same excitation intensity,the horizontal component motion produces stronger response as the excitation frequency is increasing,more close to the resonance frequency. The correlation between vertical component response and frequency depends on the structure of model slope. (3) When the excitation intensity increases,the decay of slope structure (i.e. decease of resonance frequency) does not always cause attenuation of response,instead,high frequency excitation still can produce strong response due to the narrowing gap between excitation frequency and resonance frequency. (4) The layered model slope responses more severely than the isotropic model slope. Under strong motion,the structure effect is intensified for horizontal component and weakened for vertical component as excitation frequency increases.
刘汉香,许 强,王 龙,侯红娟. 地震波频率对岩质斜坡加速度动力响应规律的影响[J]. 岩石力学与工程学报, 2014, 33(1): 125-133.
LIU Hanxiang,XU Qiang,WANG Long,HOU Hongjuan. EFFECT OF FREQUENCY OF SEISMIC WAVE ON
ACCELERATION RESPONSE OF ROCK SLOPES. , 2014, 33(1): 125-133.
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