Study on the Influence of a Soft Soil Interlayer on Spatially Varying Ground Motions

Applied Sciences

Erlei Yao¹  Weichao Li¹  Zhaowei Yang¹  Lin Ye²  Yu Miao² 

[1] Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources, Changjiang River Scientific Research Institute, Wuhan 430010, China;School of Civil and Hydraulic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;

关键词: soft soil interlayer;    lagged coherency;    spatially varying ground motions;    one-dimensional wave propagation theory;    time-varying transfer function;    non-linear soil behavior;   

DOI  :  10.3390/app12031322

来源: DOAJ

【 摘 要 】

The existence of local soft interlayer can significantly amplify or attenuate the ground motion and thus might influence the lagged spatial coherency between spatially varying earthquake ground motions. A target site with a local soft interlayer was assumed first, and then two numerical examples were set. In example 1, linear soil behavior was considered and a large amount of quasi-stationary spatially varying earthquake ground motions were generated by combining the one-dimensional wave propagation theory and the classical spectral representation method. The influence regularity of varying shear wave velocity, buried depth, and thickness of the soft interlayer on the characteristics of lagged spatial coherency was investigated. In example 2, non-linear soil behavior was taken into account and fully non-stationary spatially varying earthquake ground motions were thus generated by using time-varying transfer function and spectral representation method. An overall evaluation was carried out to shed light on the differences of characteristics of spatial coherency between non-linear soil and linear soil cases. It showed that: (i) As the shear wave velocity of interlayer declines and as the buried depth and thickness increase, remarkable reduction of spatial coherency showed up; (ii) the reduction of lagged spatial coherency caused by varying buried depth may be more inclined to concentrate in the lower frequency range; (iii) the non-linear soil behavior can cause greater further reduction of lagged spatial coherency in comparison with linear soil behavior, especially in the higher frequency range; (iv) the troughs of lagged spatial coherency curve tend to be located in the variation range of vibration frequency of time-varying spectral ratio.

【 授权许可】

Unknown