Abstract:Ground fissures are densely distributed in the Xi'an area. Buildings that are "near the seam and built" are very common, which influences land use and planning in the urban zones. To research the dynamic effects of the ground fissures, this paper chose the Xi'an ground fissure site as the object of the research. After performing the shaking table test and FLAC3D numerical simulation, the dynamic response characteristics, such as acceleration amplitude of the ground fissure site, were analyzed. On this basis, the influence of different types of seismic waves, the fracture surface's dip angle at the ground fissure, the intensity of ground motion, and the soil dislocation on both sides of the ground fissures were further analyzed. The results showed that the ground fissures had an obvious effect on the dynamic response of the site, and that the peak acceleration, in a certain range, was zonal in distribution, i.e., the peak acceleration at the ground fissure was the largest. With increasing distance from the ground fissure, the peak acceleration gradually declined, becoming stable; the range of the zonal distribution was about 30 m in the hanging wall, and about 20 m in the footwall. The dynamic response of the ground fissure site showed an obvious "hanging wall effect," i.e., the peak acceleration of the hanging wall was slightly larger than that of the footwall. The ground motion intensity had an obvious effect on the dynamic response of the ground fissure site, while the dip angle of the ground fissure, seismic waves, and the soil dislocation on both sides of the ground fissures had no obvious effect on the dynamic response of the ground fissure site.
