堆石体K_0状态单向压缩流变实验研究  

Experimental study of unidirectional compression creep in K_0 state for rockfill material

作　　者：石修松[1] 左永振[1] 张婷[1] 王路君[1] 

机构地区：[1]长江科学院水利部岩土力学与工程重点实验室,湖北武汉430010

出　　处：《煤炭学报》2010年第9期1451-1455,共5页Journal of China Coal Society

摘　　要：对两种堆石体进行了大型叠环式压缩蠕变试验,发现堆石体的应力-应变等时曲线具有明显的阶段性,当应力较低(0<σ<0.4MPa)时,应力-应变等时关系接近于线性;当应力较高(σ>0.4MPa)时,应力-应变等时关系呈现非线性,其非线性程度随着应力的增加和时间的延续而增强。根据堆石体应力-应变等时曲线的特性,对低应力段采用线性函数拟合,高应力段采用双曲线拟合。用实验得到的应力-应变关系代替Singh-Mitchell模型的应力-应变关系,保留模型原有的应变-时间关系描述堆石体的压缩流变特性,在此基础上,建立了堆石体K0状态的非线性压缩流变模型,求出了两种堆石体的模型参数。反演分析表明,该模型基本可以描述堆石体K0状态的流变行为。Gave two groups of stacked-ring compression creep test of two different rockfill materials.The results show that the isochronous stress-strain curve shows a clear phase.When the stress is low（0 σ 0.4 MPa） the relationship of stress-strain is close to linear.While the stress increases to 0.4 MPa,the nonlinear relation appears and its nonlinearity increase with the stress.Based on features of stress-strain curves,used linear function to segment of low stress and hyperbolic function to segment of high stress.The tress-strain relationship of Singh-Mitchell model is substituted by stress-strain function obtained in compression creep test.The strain-time relationship of Singh-Mitchell model is reserved to describe coarse grained material＇s creep characteristic.Then established nonlinear creep model in K0 state and the creep parameters of rockfill used in the test were obtained.Back analysis indicates that this model can mainly describe the creep characteristic of those two rockfill material in K0 state.

关 键 词：堆石体 压缩试验 等时曲线 流变 Singh-Mitchell模型 

分 类 号：TU452[建筑科学—岩土工程]