###### Abstract  
During strong earthquakes, the vertical seismic force becomes an essential factor affecting shallow underground structures that cannot be ignored. In this situation, it is proposed that ring spring-friction pendulum two-way seismic isolation bearings be set up at the bottom of such structures. Targeting the Dakai underground station and the Kobe earthquake, a soil-structure force model was established based on the damage to the underground structure and dynamic simulation was carried out using Abaqus software. The advantages of the ring spring-friction pendulum bearing over the ring spring bearing alone and the friction pendulum bearing alone were compared. The simulation results showed that the structure displayed a good seismic isolation effect in both horizontal and vertical directions after setting the ring spring-friction pendulum bearing. The deflection in the midspan of the roof reduced to less than 5 cm, the horizontal relative displacement of the structure reduced to less than 3 cm, there was no obvious damage to the structure, the axial pressure ratio of the mid-pillar reduced to less than 0.5, the axial force on the mid-pillar reduced by more than 50%, and the shear force reduced by more than 30%. In addition, by comparing the damage to the structure after setting the annular spring bearing and the friction pendulum bearing, we found that a vertical seismic isolation device is more crucial than a horizontal seismic isolation device for shallow underground structures. Setting a vertical damping device can make the structure retain part of the ductility and reduce the damage to the structure, so the ground vertical seismic mitigation design should be strengthened when a shallow underground structure is designed. bidirectional damping device; ring spring; friction pendulum bearing; shock-insulation of underground structures +
Footnote †: journal: Applied Sciences  
and underground shopping streets, were damaged, with the most serious damage being to subway station structures [3]. The 1999 Kokkaieri (Izmit) earthquake in Turkey caused significant permanent deformation of subsurface structures and soils in the Adapazal region [4]. In the Wenchuan ms 8.0 earthquake in 2008, the main structure of four stations of the Chengdu subway was damaged, with many cracks in the station walls and water seepage at the cracks; the shield tunnel sections had obvious cracks, misalignment, anchor rod fractures, water seepage, and other earthquake damage phenomena, and the area of water seepage between the section and the circle increased [5]. Once earthquake damage occurs in underground structures, it not only causes huge casualties and property damage but also makes the post-earthquake repair work of underground structures even more difficult. Therefore, the aseismic design of underground structures is essential. After the Wenchuan earthquake, the engineering aseismic community reached a consensus that the application of aseismic technologies and energy dissipation technologies in engineering structures should be vigorously promoted, using aseismic elements or energy dissipation damping devices to consume most of the earthquake input energy and the main structural members only absorbing or storing a small portion of the kinetic and deformation energy so as to ensure the safety of the main structural members. The research on seismic isolation technology started with ground building structures, among which typical seismic isolation devices are friction pendulum bearings, which have been widely used in many large-span space structures and bridge structures because of their low cost, simple construction, and high load-bearing capacity. In 1995, [PERSON] et al. [6] performed a finite element analysis of the seismic response of industrial storage tanks with FPB, and the results showed that FPB can not only reduce the risk of leakage or damage to the structure during an earthquake but also make the structure design more economical and reasonable.