# Seismic Response and Mitigation Analysis of a Subway Station in the Site with Weak Interlayers
## 1 Introduction  
With rapid global development and exponential population growth, the pursuit of more extensive living spaces has made the development and utilization of underground areas a vital direction for advancement. Currently, underground structures have broad applications across various construction domains, with subway projects being notable examples within this realm. Rock formations and soil exert constraints on the vibrational deformations of underground structures. Hence, it was commonly believed that underground structures exhibited superior seismic performance compared to their above-ground counterparts. However, until the 1990s, there was a scarcity of seismic damage data related to underground structures, which resulted in a prolonged lack of emphasis on seismic analysis theories and design methods in this field [1; 2; 3]. Recent seismic disasters have highlighted the vulnerability of underground structures to earthquakes, with some experiencing severe damage [4; 5; 6; 7]. For instance, during the Great Hanshin Earthquake in Japan, Daikai station suffered extensive destruction. The Great Hanshin Earthquake's powerful horizontal and vertical seismic forces caused the central column to fracture, resulting in the roof's collapse and creating a distinctive \"M\" shaped pattern of devastation [8]. This earthquake-induced damage has acted as a wake-up call for experts and scholars worldwide. Complex site characteristics significantly impact the safety of underground structures and weak interlayers are a common variety among these complex site types. Consequently, the study of weak interlayer's impact on underground structures holds significant importance for seismic design. [PERSON] et al. [9] employed a combination of scaled model testing and numerical analysis to investigate the influence of rock faults and weak surfaces on the stability of underground structures. [PERSON] et al. [10] conducted model testing and numerical simulations, concluding that factors such as position, angle, thickness, and distance from the tunnel significantly affect tunnel stability. Some scholars [11; 12; 13; 14] pointed out in their work that adverse soft soil conditions exacerbate the deformation of subway station structures. [PERSON] et al. [15; 16]. taking into account the influence of the soil-structure interaction and structural depth, conducted vulnerability assessments for circular tunnels located within soft interlayers in the Shanghai subway system. Since the Great Hanshin Earthquake, seismic mitigation measures for underground structures have garnered significant research attention. Some engineers [17; 18; 19; 20] have proposed the seismic mitigation scheme by installing an isolation layer between the rock and lining, resulting in the isolation layer reducing the deformation of the lining. [PERSON] et al. [21] delved into the utilization of isolation layers for underground structures and conducted pertinent experimental studies. The results showed that isolation layers can absorb seismic energy and efficiently reduce structural bending moments. Several scholars [22; 23; 24; 25] carried out research on Daikai stations, which suffered the most damage during the Great Hanshin Earthquake. Their results demonstrated that the central column of subway station structure is particularly susceptible to seismic forces and prone to shear failures under earthquake motion. Therefore, mitigating shear deformations of central column under seismic forces is a crucial step in enhancing the seismic performance of subways. Studies have investigated the seismic mitigation effects of various approaches, including rubber bearings on the top of the central column [26; 27; 28], shear plate dampers [29], sliding bearings [30; 31; 32], and split columns [33]. The results indicated that all these measures effectively reduce the shear deformations of the central column. Rubber bearing is a commonly used form of seismic mitigation support.