Seismic behavior of brick cave dwellings: Shake table tests

Brick cave dwellings are a traditional residence widely built and used in the Loess Plateau of China, but the current understanding of their seismic performance is still scarce. In the present study, the weak areas and dynamic response characteristics of brick cave dwellings were explored by performing shake table tests on a 1:4 scaled model. The test results indicate a noticeable increase in the structural model's dynamic response and damage when the PGA (Peak Ground Acceleration) was 0.5 g, while the structural stiffness substantially degraded when the PGA reached 0.6 g. The severely damaged areas on the structural model mainly refer to the piers, middle barrel vault, and Yaolian, and the damage cracks at the wall junctions were denser in particular. Along with the PGA increases, the stiffness degradation of the pier story and roof story was higher than that of the vault story, leading to differences in the dynamic responses between the three stories. Since the flexibility and stiffness degradation of the middle piers were higher than that of the lateral piers, the vertical displacement response of the middle barrel vault constrained by the middle piers was considerably higher than that of the lateral barrel vault. When the chambers opened on the Yaolian of the brick cave dwellings and caused an eccentric distribution in structural stiffness, the dynamic responses of the Yaolian and back wall were rendered differently while a torsion effect was produced. Further analysis also showed that the accumulated hysteresis energy dissipation of each structure story was not the same, the energy dissipation by inelastic deformation increased significantly when the PGA reached 0.6 g, and the structure entered the elastoplastic stage.