层状地基桩柱结构地震响应特性研究

发布时间：2018-05-08 05:45

本文选题：层状土层 + 地震波　；参考：《地震工程与工程振动》2017年05期

【摘要】：为研究自然地质环境条件下非均质层状地基对结构物地震响应的影响,本文通过层状饱和土的刚度矩阵的建立,对不同夹层条件下的地基地震响应进行了对比研究。研究结果表明:相较于均质土层地基,由于非均质地基土层存在的非连续性界面,非均质夹层能明显影响地基的波动响应特征,对地震波有着显著的选择性滤波作用,尤其在含软夹层地基条件下能极大削弱入射波中的高频成分,而硬夹层则能极大滤除地震波中的低频成分。在对地基地震响应研究的基础上,通过对单桩和群桩码头结构的地震响应的数值模拟,对含夹层地基条件下不同刚度结构地震响应特性进行了对比研究。对比研究表明:对不同刚度的结构物,由于其固有自振频率的差异,不同夹层地基对其地震动力响应存在显著不同的影响规律,由于单桩结构较低的固有频率,使得其对低频波更为敏感,其固有振型在含软夹层地基条件下更容易被激发引起结构共振,而群桩结构则刚好相反,由于其更高的固有频率,在软夹层地基条件下由于高频波的滤除使得结构的地震动力响应显著降低,而在均质或含硬夹层条件下更容易激发其固有振型。通过对不同夹层地基条件下结构地震动力响应规律的研究,可以看出结构的地震动力响应同时受地基夹层条件以及结构自身动力特性的影响,相关研究结论可为非均质地基条件下的结构地震响应研究提供参考。
[Abstract]:In order to study the effect of heterogeneous layered foundation on the seismic response of structure under natural geological environment, the seismic response of different intercalation conditions is studied by establishing the stiffness matrix of layered saturated soil. The results show that, compared with the homogeneous soil foundation, because of the discontinuous interface in the heterogeneous soil layer, the heterogeneous intercalation can obviously affect the response characteristics of the foundation, and it has a remarkable selective filtering effect on the seismic wave. Especially under the condition of soft intercalation, the high frequency component of the incident wave can be greatly weakened, and the low frequency component of the seismic wave can be greatly filtered by the hard interlayer. On the basis of the research on the seismic response of foundation, the seismic response characteristics of different stiffness structures under the condition of sandwich foundation are studied by numerical simulation of the seismic response of single pile and pile group wharf structure. The comparative study shows that for structures with different stiffness, due to the difference of natural vibration frequencies, there are significant differences in the seismic dynamic responses of different sandwich foundations, because of the lower natural frequencies of single pile structures. It makes it more sensitive to low-frequency waves, and its natural mode is more easily excited to cause structural resonance under the condition of soft sandwich foundation, whereas the pile group structure is just the opposite, because of its higher natural frequency, The seismic dynamic response of the structure is significantly reduced due to the filtering of high frequency waves in the soft sandwich foundation, and the natural mode of the structure is more easily excited under the condition of homogeneous or hard intercalation. Through the study of seismic dynamic response of structures under different sandwich foundation conditions, it can be seen that the seismic dynamic responses of structures are affected by the intercalation conditions of foundation and the dynamic characteristics of the structures themselves. The relevant conclusions can be used as a reference for the study of seismic response of structures under heterogeneous ground conditions.
【作者单位】：广东海洋大学海洋工程学院;河海大学港口海岸与近海工程学院;大连理工大学港口海岸与近海工程国家重点实验室;
【基金】：广东海洋大学创新强校工程科研项目(GDOU2016050258)~~
【分类号】：TU435

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