The Dynamic Response Characteristics of Sites with Earth Fissures
Jiang CHANG1#+, Yahong DENG1, Huangdong MU2
1Chang`an University, China, 2Xi`an University of Technology, China

As a widespread geological hazard, the disaster development process of earth fissures is irreversible and difficult to control, which seriously affects the construction and safe operation of engineering facilities. However, few clear conclusions and special regulations have been given regarding the influence of earth fissures on the dynamic response characteristics of a site and earthquake prevention and disaster reduction measures. With the aim of providing previously lacking advice regarding earthquake fortification in proximity to fissures, systematic microtremors testing were conducted. The typical earth fissures in the Fenwei Basin were taken as as the research object and more than 40 microtremor survey lines were laid. In order to reveal the dynamic response of microtremors from several aspects, four methods, including the Fourier spectrum, the horizontal-to-vertical spectral ratio (HVSR), the response acceleration, and the Arias intensity, were employed. Finally, the dynamic response characteristics, influencing factors, ground motion amplification effect, influence range, engineering protection distance and seismic fortification criteria of earth fissure sites are revealed and proposed. The results show that a greater dynamic response can be found near the earth fissure. The amplification effect decreases and eventually disappears with increasing distance from the fissure. A series of amplification attenuation curves were calculated, the empirical equations of various sites were determined and seismic fortification distance were estimated. Research on the dynamic response amplification effect of earth fissure sites will also provide technical support to disaster prevention and mitigation of similar sites.