Abstract:
To study the seismic performance of damaged underground loess cave dwelling after reinforcement, a damaged structural model with scale raito of 1/5 was retrofitted by replacing loess modified with water-glass and implanting reinforcement cages, and then a shaking table test was conducted on the retrofitted structural model. By analyzing the frequency response function of each measuring point due to white noise excitation, the displacement response, acceleration response and failure characteristics of the retrofitted structure under different working conditions were obtained. On this basis, the dynamic characteristics and hysteretic energy dissipation of the model structure during each loading stage were studied. The results show that the damage appears and accumulates in the retrofitted structure with the increase of peak ground acceleration input. The natural frequency and equivalent stiffness gradually decrease, while the damping ratio increases significantly. The acceleration amplification factor of each story is between 1.02 and 1.41. Moreover, compared with the original structure, the locations of shear cracks in the retrofitted structure are no longer concentrated in the vault area, but are mainly distributed in the roof area, indicating that the weak area has been transferred to the non-critical area. Subjected to the rare major earthquake of 8-degree, the retrofitted model shakes violently, but it does not collapse, indicating that the above retrofitting measures effectively enhance the collapse resistance of the damaged underground loess cave dwellings.