含软弱夹层顺层岩质边坡传递函数及其应用研究

发布时间：2018-05-27 03:41

本文选题：软弱夹层 + 顺层　；参考：《岩土力学》2017年04期

【摘要】：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。
[Abstract]:Based on the model test of large shaking table and transfer function theory, the absolute transfer function and relative transfer function of rock slope with weak intercalation are compared and analyzed, and the accuracy of the two transfer functions in calculating the dynamic characteristic parameters of slope is discussed. The feasibility of estimating the dynamic response of slope in frequency domain by transfer function is studied. The results show that the shape of the transfer function curve calculated by the time history of the slope and the acceleration in the slope is similar, but the difference in amplitude is small. The real part of the relative transfer function is 1 less than the real part of the absolute transfer function, the imaginary part of the absolute transfer function and the relative transfer function coincide with each other, and the symmetry of the peak value of the imaginary part of the two transfer functions is better. The accuracy of calculating slope dynamic characteristic parameters by transfer function imaginary part is high. When the frequency is greater than 10 Hz, the relative transfer function mode tends to 1 and the absolute transfer function mode tends to 0. The natural frequencies of slope calculated by using the imaginary part of the two transfer functions and the relative transfer function modes are very close. The damping ratio calculated by the two transfer function models is more accurate. The results show that the damping ratio of the bedding rock slope with weak intercalation is greater than that of the homogeneous rock slope. The acceleration modes of the bedding rock slope with weak intercalation are the same as those obtained by using the imaginary part of the two transfer functions and the model calculation. The accuracy of estimating the frequency domain dynamic response of rock slope with weak intercalation by using absolute transfer function is higher than that with relative transfer function. Using transfer function to modify the spectral characteristics of the input ground motion is helpful to ensure the rationality of the input mechanism of the dynamic response of the bedding rock slope with weak intercalation.
【作者单位】：西南交通大学土木工程学院岩土工程系;西南交通大学交通隧道工程教育部重点实验室;
【基金】：交通运输部建设科技项目(No.2013318800020) 国家重点基础研究发展计划(973计划)(No.2011CB013605)~~
【分类号】：TU45

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