Shaking table tests on seismic behavior of the underground loess cave of earth building of traditional dwellings

摘要

This paper presents the results of an experimental work in order to evaluate the seismic performance of a underground loess cave by shaking table test, which provides an important theoretical basis for protection of the underground loess cave. For this purpose, one specimen, scaled 1:5, were subjected to a shaking table test. The white noise sweep and the loading of three different spectral characteristics of the seismic wave were carried out on the experimental model. The quantitative analysis of the acceleration response and displacement response of the model were made under various loading conditions. The displacement response of each key part in the cave was similar forced vibration same as the excitation inputs. Based on the experimental phenomena and experimental analysis results, the failure mechanism of the underground loess caves under lateral horizontal earthquakes was studied. The analysis results showed that under the horizontal earthquake, the underground loess cave had shear deformation between the soil layers and the movement difference between the middle leg and the side leg in the cave. And the failure with oblique crack was produced at the upper of the arch apex, because of the combined action of normal stress and shear stress.