Physical simulation of ground fissures triggered by underground fault activity

Numerical modeling and physical simulation experiment are two important steps to investigate the stress and strain fields of overlying strata, but sometimes it is very difficult to do the test of the physical experiment on a large-scale soil sample due to the financial consideration and the available test site. To investigate the features of the ground fissures prevailing in Xiʹan City, we undertook in this study a series of physical simulation tests on the large-scale soil sample to analyze the stress and displacement fields caused by the underlying normal fault activity. Comparing with the fracturing modes of the ground fissures and the failure patterns of construction building, it is evident that the experiment results coincide with the failure patterns of the building, but not with the fracturing modes of the ground fissures, which indicate that the ground fissures in Xiʹan may be an old fracture surface having already spread to superficial layer covered by a very thin layer of loose soils, and the groundwater over-pumping is just a factor to make them exposed on the ground surface.