摘要
采用分级增量循环加卸载方式,利用SR-6型三联式三轴蠕变仪对陕西省泾阳县某边坡原状黄土进行了三组室内三轴固结排水蠕变试验,着重研究了黄土黏弹塑性的基本规律,以此建立了黏弹塑性九元件蠕变模型。结果表明:该地区原状黄土具有明显的流变特性,总体呈线性衰减蠕变;卸载后,土样产生衰减黏弹性回弹变形,回弹量随着卸荷量的减小,围压的增大,含水率的增大而减小;加卸载应力历史对黄土蠕变变形具有累积效应;该地区原状黄土的回弹变形不明显,黏弹性变形在蠕应变中所占比重较小;所建立的元件蠕变模型可以较好地描述该地区黄土的三轴线性蠕变特性,物理意义明确,且模型参数易得。
Three groups of laboratory consolidated drained triaxial creep tests are conducted on a triaxial creep instrument SR-6,by exerting circular incremental load and unload by steps on the undisturbed loess from a loess slope of Xianyang City in Shaanxi Province. The experiments focus on the basic rules of viscoelasto-plastic characteristic of the loess,based on which a viscoelasto-plastic nine-element creep model is established. The results indicate that the undisturbed loess in this area has obvious rheological property and overall shows a linear attenuation creep. After unloading,the soil samples generate attenuated viscoelastic rebound deformation which decreases as the unloading decreases,while confining pressure and moisture content increases. Loading and unloading history has a cumulative effect on soil creep deformation; The rebound deformation of the undisturbed loess in this area is not as obvious,and the proportion of viscoelastic deformation in the creep strain is small. The model can be applied to characterize the triaxial linear creep properties of undisturbed loess and has clear physical meaning as well as easier method of obtaining parameters.
出处
《地下空间与工程学报》
CSCD
北大核心
2014年第6期1237-1242,共6页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金资助项目(51178392)
关键词
Q3黄土
分级加卸载
三轴蠕变试验
蠕变特性
九元件蠕变模型
Q3 loess
loading and unloading by steps
triaxial creep test
creep characteristics
nine-element creep model
