Earthquake Hazards Vulnerability Analysis of The Nankou-Sunhe Fault in Changping (Beijing) Using HVSR Method

Abstract

During the Holocene period, three paleoseismic events (Mw=7.7-7.9) occurred on the Nankou-Sunhe Fault in Beijing. For disaster prevention and mitigation, earthquake zoning is needed to be carried out to map the areas that will experience severe damage when an earthquake occurs. This study uses the Horizontal to Vertical Spectral Ratio (HVSR) method to obtain not only the sedimentary layer thickness and fault structure according to empirical formulas, but also the spatial variations in the peak frequency and amplification values that can explain the characteristics of the geological layer beneath the surface. Based on the calculated results, the peak frequency(f) ranges from 0.2 to 4 Hz with the lowest frequency distribution in the southwest parts, which indicates a thicker sediment layer. Amplification(A) ranges from 2 to 14 with the distribution of higher values in the southeastern and northeastern parts. The K-value (A2/f) is in the range of 0-180 and the highest K-value in the southwest of the fracture indicates that this region is at high risk for damage. Our results provide a better understanding of the earthquake hazards vulnerability of the Nankou-Sunhe Fault in Changping, Beijing, and can be used as a basis for urban disaster prevention and reduction.