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基于大型振动台模型试验及传递函数理论,对含软弱夹层顺层岩质边坡的绝对传递函数和相对传递函数进行了对比分析,探讨了两种传递函数计算边坡动力特性参数的准确性,并对利用传递函数估算边坡频域动力响应的可行性进行了研究。研究结果表明,采用坡面及坡内加速度时程计算得到的传递函数曲线形态相近,幅值差别较小;相对传递函数实部比绝对传递函数实部小1,绝对传递函数和相对传递函数虚部重合,且两种传递函数虚部峰值两侧对称性较好,利用传递函数虚部计算边坡动力特性参数准确性较高。在频率大于10 Hz部分,相对传递函数模趋于1,绝对传递函数模趋于0。利用两种传递函数虚部及相对传递函数模计算得到的边坡固有频率十分接近。两种传递函数模计算得到的阻尼比比较准确,计算结果表明,含软弱夹层顺层岩质边坡的阻尼比大于均质岩质边坡。利用两种传递函数虚部及模计算得到的含软弱夹层顺层岩质边坡加速度振型相同。利用绝对传递函数估算含软弱夹层顺层岩质边坡频域动力响应的准确性高于相对传递函数估算结果。利用传递函数对输入地震动的频谱特性进行修正有利于保证含软弱夹层顺层岩质边坡动力响应研究输入机制的合理性。
Based on the large-scale shaking table test and transfer function theory, the absolute transfer function and the relative transfer function of the bedding rock slope with weak interbed are compared and analyzed. The accuracy of the dynamic characteristic parameters of the slope is discussed by using two transfer functions. The feasibility of using the transfer function to estimate the dynamic response of the slope in frequency domain was also studied. The results show that the curve of the transfer function calculated by the time history of slope and slope acceleration is similar in shape and the difference in amplitude is small. The real part of the relative transfer function is smaller than the real part of the absolute transfer function. The absolute transfer function and the relative transfer function And the symmetry of the two imaginary peaks of the two kinds of transfer functions is better. The accuracy of slope dynamic characteristic parameters calculated by the imaginary part of the transfer function is high. In the frequency greater than 10 Hz part, the relative transfer function modulus tends to 1, the absolute transfer function modulus tends to 0. The natural frequencies of slopes calculated by using the imaginary part of two transfer functions and the relative transfer function are very close. The damping ratio calculated by the two transfer function models is more accurate. The calculated results show that the damping ratio of bedding rock slope with soft interlayer is larger than that of homogeneous rock slope. The acceleration modes of the rock slope with the weak interlayer are obtained by using the imaginary part and the model of the two transfer functions. Using absolute transfer function to estimate the frequency response of rock mass slope with weak interlayer is more accurate than the relative transfer function. Using the transfer function to correct the spectral characteristics of input ground motions is helpful to ensure the rationality of the input mechanism of the dynamic response of the rock bedding rock with soft interlayer.