Rayleigh-Wave Dispersion Analysis and Inversion Based on the Rotation.

Lixia Sun,Xinming Qiu,Yun Wang

doi:10.3390/s22030983

Lixia Sun, Xinming Qiu + Show 1 more

Open Access

https://doi.org/10.3390/s22030983

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Abstract

Rotational observation is essential for a comprehensive description of the ground motion, and can provide additional wave-field information. With respect to the three typical layered models in shallow engineering geology, under the assumption of linear small deformation, we simulate the 2-dimensional radial, vertical, and rotational components of the wave fields and analyze the different characteristics of Rayleigh wave dispersion recorded for the rotational and translational components. Then, we compare the results of single-component inversion with the results of multi-component joint inversion. It is found that the rotational component has wider spectral bands and more higher modes than the translational components, especially at high frequencies; the rotational component has better anti-interference performance in the noisy data test, and it can improve the inversion accuracy of the shallow shear-wave velocity. The field examples also show the significant advantages of the joint utility of the translational and rotational components, especially when a low-velocity layer exists. Rotational observation shall be beneficial for shallow surface-wave exploration.

Highlights

Surface-wave exploration is an important method in the field of geophysics used for the detection of the shallow shear-wave velocity structure of the earth, and includes single-station method, two-station method [1], two-plane-wave method [2], ambient noise tomography based on passive source [3], microtremor method [4,5,6], rotational seismic method [7,8], and the most widely used method in the seismic exploration—multi-channel analysis of surface waves (Rayleigh and Love waves) [9,10]
Numerous experimental studies have used high-speed railway vibration signals for extracting the dispersion curves of the surface waves [11] and used the surface waves detected by an urban telecommunication optic-fiber cable to obtain the shallow velocity structure [12]
Limited by space of the paper, we only show the single-component inversion results for clearer comparison, since there are great similarities between the rotational component inversion results and the joint multi-component inversion results in the numerical test

Summary

Introduction

Surface-wave exploration is an important method in the field of geophysics used for the detection of the shallow shear-wave velocity structure of the earth, and includes single-station method, two-station method [1], two-plane-wave method [2], ambient noise tomography based on passive source [3], microtremor method [4,5,6], rotational seismic method [7,8], and the most widely used method in the seismic exploration—multi-channel analysis of surface waves (Rayleigh and Love waves) [9,10].In recent years, numerous experimental studies have used high-speed railway vibration signals for extracting the dispersion curves of the surface waves [11] and used the surface waves detected by an urban telecommunication optic-fiber cable to obtain the shallow velocity structure [12]. Due to the poor applicability of the fundamental-mode surface waves for complex media (containing a low-velocity interlayer and a high-velocity interlayer) [13], the joint utilization of the fundamental and the higher modes has attracted extensive attention [14,15,16,17] and led to better applications [18,19,20,21]. The high-resolution linear Radon transform [25] and the complex vector method, which jointly use the multi-component seismic data, show good results in extracting the surface-wave dispersion curves of different modes [26]. The joint use of the radial and vertical components of seismic translational motions to invert the shallow velocity structure has been widely used [27,28,29,30,31]

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