Seismic responses of the densely distributed caves of the Mogao Grottoes in China

摘要: Some of the largest and best-preserved Buddhist art treasure houses in world, namely Mogao Grottoes, are located at northwest edge region Qinghai-Tibet plateau adjacent to Altun Qilian mountains, where geotectonic activity is intense large earthquakes have occurred. Future one major threats caves Grottoes; therefore, it important that their dynamic performance studied when an earthquake occurs. To understand densely distributed under effect earthquakes, as well long-term stability stress distribution, deformation characteristics, peak-acceleration amplification factor were analysed rare-earthquake conditions using a finite-difference element. The numerical study revealed most dangerous state initial time obvious tensile concentration appeared top bottom middle floor; main damage was caused by shear failure towards direction free face not failure. A permanent horizontal displacement occurred after earthquake, mostly floor. acceleration middle-floor significant; Fourier amplitudes (which monitored all caves) significantly magnified frequencies 3 ~ 4 Hz 7 ~ 9 Hz, whereas which almost amplified within entire frequency range. Although maximum allowed limit no occurred, great inhomogeneous displacements accelerations could negative on preservation wall paintings. Moreover, assumed calculation results serve type guidance advice preventive protection Grottoes.