中文摘要：

为研究离子型稀土矿体蠕变特性,基于GDS三轴试验系统,对原状矿样进行不同围压和含水率下的三轴蠕变试验。结果发现：偏应力水平不超过50%,矿样主要发生衰减蠕变变形,且以瞬时弹性变形为主,蠕变变形量很小,矿样处于稳定状态。当偏应力水平达到70%,矿样发生非稳定蠕变,在经历减速蠕变和等速蠕变后,变形迅速发展,矿样在短时间内破坏。围压和含水率对离子型稀土矿体在加速蠕变阶段的变形特性影响显著,围压越小,矿样越早进入加速蠕变阶段,发生破坏的时间越短;含水率越大,矿样破坏时变形量越大,强度降低越明显。基于蠕变试验数据,分别探讨Burgers模型、西原正夫模型以及幂函数模型的适用性;并且在Burgers模型基础上引入非线性黏滞元件,建立一种新的非线性黏弹塑性模型。该模型能较好描述离子型稀土矿体蠕变全过程。

英文摘要：

In order to study the creep characteristics of ion-adsorption rare-earth ore, triaxial creep test were carried on undisturbed ore with various confining pressure and moisture content, based on GDS unsaturated triaxial test system, the experimental results show that under deviatoric stress level of no more than 50% , stable creep is mainly appeared, instantaneous elastic deformation accounted for the main part, creep deformation is very small, samples in a steady state. Deviatoric stress level reaches 70% , unsteady creep occurred, samples damaged in a short period of time with rapid development of deformation, after deceleration creep and equal velocity creep. Confining pressure and moisture content have a great effect on deformation characteristics, the samples reach acceleration creep soon with reduction of confining pressure, destruction time is sooner. Great deformation and softening strength occurred with increase of moisture content. Based on test results, the applicability of the Burgers model、Nishihara Masao model and power function model were discussed, based on Burgers model, nonlinear viscous element was introduced to establish a new visco-elasto-plastic model,which can describe the whole process of creep of ion-adsorption rare-earth ore.