## 6 Analysis of Dynamic Effects of the Earth Fissure  
### Amplification Effect  
In order to more intuitively reveal the degree and scope of the impact of the earth fissures on the dynamic response of the site, the concept of the amplification factor was introduced. Figure 12 shows that the amplitudes of the three measurement points on both sides of the earth fissure on each survey line were basically the same and tended to be stable. Therefore, the stable amplitude was defined as the average of the amplitudes of these three measurement points, and the amplification factor was defined as the average amplitude of each measurement point divided by the stationary amplitude. Figure 12 shows the attenuation curve and fitting curve of the amplification factor with distance. As can be seen from the figure, the earth fissure site amplification effect revealed via Fourier spectrum, response spectrum, and Arias intensity had the same attenuation mode, and the dynamic amplification response of the site was most significant when closest to the earth fissure and tended to decay as the distance from the fissure increased until reaching the area farthest away from the earth fissure, where the dynamic response of the site gradually stabilized and the amplification factor approached 1. This also indicates that the influence of the earth fissure on the dynamic response of the site had a limited range.  
According to the amplification factor fitting curve (Figure 12), we can obtain the amplification factor extreme value of different analysis results. As shown in Table 1, the extreme value of the hanging and heading sides obtained by the Fourier method is 1.8-2.1. The extreme value of the amplification factor of the hanging side obtained by the response spectrum is 1.8, and that of the heading side is 1.6, while the Arisa intensity has the largest amplification factor extreme values of 3.2 for the hanging side and 2.9 for that of the heading. The amplification factors obtained by three analysis methods are different, we can choose different amplification factors according to the needs of seismic fortification. The Fourier method focuses on the inherent information of the site soil layer, which can intuitively reflect the vibration characteristics of the site. Therefore, we can select the Fourier amplification factor when considering only the dynamic characteristics of the site  
Figure 11: The amplitude attenuation curves of each site.  
itself. The response spectrum can reflect the dynamic characteristics of different structural particle systems under ground motion, which is very effective for the seismic fortification of structures. The Arias intensity is a time-dependent curve, indicating the strength of the overall dynamic response of the site over a period of time. According to the amplification factor of the Arias intensity, the peak acceleration of the site under seismic action can be obtained, and the seismic fortification level of the site can be adjusted. Different methods show that the extreme value of the amplification factor in the hanging side of the same earth fissure site is slightly larger than that of the heading. Therefore, under the dynamic load, when the distance from the earth fissure is the same, the dynamic amplification response of the hanging side is stronger.  
Figure 12: Amplification factor diagrams of the different analyses. (**a**) Fourier amplification factor and fitting curve, (**b**) response spectrum amplification factor and fitting curve, and (**c**) Arias intensity amplification factor and fitting curve.