武文举, 马艳霞, 张吾渝, et al. An Experimental Study on the Dynamic Stress-Strain Relationship of Intact Loess under Cyclic Loading[J]. 2018, 38(4): 731-737. DOI: 10.13409/j.cnki.jdpme.2018.04.018.
An Experimental Study on the Dynamic Stress-Strain Relationship of Intact Loess under Cyclic Loading
A series of laboratory tests was carried out on intact loess using the GDS bidirectional dynamic triaxial test system to investigate the dynamic stress-strain characteristics at different sampling angles associated with the index plane and at the condition of different sampling depths and confining pressures. Test results reveal that the dynamic stress-strain curves of the Xining intact loess had significant differences under different sampling angles. The anisotropic characteristics of the specimen was not apparent at the initiation of loading; a large strain increment was caused by a small stress increment when the dynamic stress is greater than 0. 8% and the specimen showed a significant anisotropic behavior. The parameters of the Hardin-Drnevich(H-D)hyperbolic model with different depths and angles were obtained in this study; the curves under different sampling angles could be described by the H-D model and showed a weak strain hardening. Meanwhile
the sampling depths and confining pressures of specimen had a significant impact on the dynamic stress-strain behavior. The dynamic stress increased with the increase of sampling depths and confining pressures. In addition
the dynamic modulus of elasticity was relatively large for deeper loess
but the increment of the dynamic elastic modulus gradually decreased with an increasing depth. This indicates that the loess can better resist vibration deformations under larger confining pressures and deeper burying depths. This study shows that the shallow loess in Xining is prone to vibration and deformation when subjected to earthquake or other dynamic loads.