Study on two-dimensional coherency function model of ground motion field

The U.S. Geological Survey Parkfield Dense Seismograph Array (UPSAR) successfully recorded strong motions during 2003 San Simeon earthquake (M 6.5) and 2004 Parkfield earthquake (M 6.0). Because the array covers a very small area (0.45km2), these data offer some interesting insights into spatial variations of seismic ground motions that suits for engineering scale. In this research, we study the spatial coherency function of seismic ground motion in the horizontal and vertical directions by digital signal processing. The results show that when the circular frequency is smaller than , the degressive trend of the coherency function becomes significant with the separation distance elongation, while the data deviation of the coherency function becomes larger with the frequency rise, which shows no obvious rules. In addition, based on the strong-motion data, a suitable spatial coherency model of ground motion is selected through comparing existing model functions, and the appropriate recommendations for improvement is put forward. Finally, according to different frequency range, the fitting parameters of the spatial coherency function of ground motion are obtained through numerical simulation. The spatial coherency function proposed in this paper is practical in simulation of ground motion field.

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Vertical coherency function model of spatial ground motion

Earthquake Engineering and Engineering Vibration ◽

10.1007/s11803-011-0076-y ◽

2011 ◽

Vol 10 (3) ◽

pp. 403-415 ◽

Cited By ~ 9

Author(s):

Jihong Ye ◽

Jinlong Pan ◽

Xianming Liu

Keyword(s):

Ground Motion ◽

Function Model ◽

Coherency Function

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Investigating the influence of topographic irregularities and two-dimensional effects on surface ground motion intensity with one- and two-dimensional analyses

Natural Hazards and Earth System Science ◽

10.5194/nhess-14-1773-2014 ◽

2014 ◽

Vol 14 (7) ◽

pp. 1773-1788 ◽

Cited By ~ 1

Author(s):

G. Ç. İnce ◽

L. Yılmazoğlu

Keyword(s):

Ground Motion ◽

Site Response ◽

Soil Conditions ◽

Response Analysis ◽

Two Dimensional ◽

Ground Acceleration ◽

Equivalent Linear ◽

Local Soil ◽

Different Depths ◽

Earthquake Response Analysis

Abstract. In this work, the surface ground motion that occurs during an earthquake in ground sections having different topographic forms has been examined with one and two dynamic site response analyses. One-dimensional analyses were undertaken using the Equivalent-Linear Earthquake Response Analysis (EERA) program based on the equivalent linear analysis principle and the Deepsoil program which is able to make both equivalent linear and nonlinear analyses and two-dimensional analyses using the Plaxis 8.2 software. The viscous damping parameters used in the dynamic site response analyses undertaken with the Plaxis 8.2 software were obtained using the DeepSoil program. In the dynamic site response analyses, the synthetic acceleration over a 475-year return period representing the earthquakes in Istanbul was used as the basis of the bedrock ground motion. The peak ground acceleration obtained different depths of soils and acceleration spectrum values have been compared. The surface topography and layer boundaries in the 5-5' cross section which cuts across the study area west to east were selected in order to examine the effect of the land topography and layer boundaries on the analysis results, and were flattened and compared with the actual status. The analysis results showed that the characteristics of the surface ground motion change in relation to the varying local soil conditions and land topography.

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