Study on the Deformation Zone of Tianzhuang Fault in Taiyuan, China

The burial depth in modern urban lifeline engineering, subway construction, and the foundations of super high-rise buildings can reach depths of up to 30 m or even deeper. Therefore, when dealing with buried faults at depths less than 60 m, it becomes essential to assess their seismic activity and study their paleo-earthquake recurrence cycles. This research holds great significance for enhancing engineering earthquake resistance and mitigating fault-related risks. The Tianzhuang fault is a concealed fault of considerable importance, exhibiting clear activity during the late Pleistocene in the Taiyuan Basin, Shanxi Province, China. This study begins by analyzing the regional geological tectonic background and subsequently delves into the tectonic processes associated with the Yanshan and Xishan movements within the Tianzhuang fault. The temporal and spatial activity characteristics of multi-stage faults are examined through the processing and interpretation of shallow seismic profiles of the Tianzhuang fault. Further insights are gained through ground deformation surveys and an analysis of borehole joint sections, which allow us to present details of the recently displaced strata in the primary section. These efforts contribute to the verification of a fault gas anomaly zone within the concealed fault and the confirmation of the extent of the deformation zone within the Tianzhuang fault since the late Pleistocene. Ultimately, this research enables the dynamic visualization of the main fault's shifting location and the formation and expansion of the fault zone within the Jiaocheng fault zone.