黏土岩时效变形特性试验与理论研究

高放废物地质处置岩体材料选取中，黏土岩因具有低渗透性、损伤自修复特性、对放射性核素具有良好的吸附作用等优点，被认为是一种合理的高放废物地质处置屏障。以黏土岩为研究对象，从黏土岩短期、长期力学特性等方面开展研究工作，主要内容如下：（1）进行黏土岩短期自然固结试验，确定了黏土岩的基本物理力学参数，主要包括前期固结压力、压缩指数等；（2）进行流-固耦合固结试验，试验结果表明盐水作用对黏土岩力学特性具有重要影响，且流-固耦合过程中的膨胀现象与黏土岩的黏土矿物含量和类型密切相关；（3）通过对黏土岩进行固结流变试验，研究黏土岩渗流-应力耦合作用下的长期力学特性，试验表明黏土岩具有明显的流变特性，且流变现象与载荷密切相关；（4）根据固结流变试验建立黏土岩一维流变本构模型，同时将模型计算结果与试验结果进行对比，分析表明，该模型能够很好地反映黏土岩一维固结流变特性。该研究对我国未来黏土岩高放废物处置库的规划、设计、选址和运营等具有重要的参考意义。

Experimental and theoretical study of the time-dependent deformation characteristics of clayey rock

Clayey rock is considered to be a reasonable geological barrier for high-level radioactive waste disposal. The research work is carried out from the aspects of both short-and long-term mechanical properties of clayey rock in the present work. Standard natural oedometer tests are carried out and basic physical and mechanical parameters such as pre-consolidation stress and compressibility coefficient are obtained. The hydro-mechanical coupling consolidation test shows that the saline has an important influence on the mechanical properties of clayey rock, and the swelling phenomenon in the hydro-mechanical coupling process is closely related to the content and type of clay minerals in clayey rock. Long-term hydro-mechanical coupled behavior of a clayey rock is studied by consolidation creep tests and the test results highlighted the creep potential of this clayey rock. Based on the test results, a creep constitutive model is established to describe the consolidated creep behavior of the clayey rock. The agreement of calculation results with the test data indicates that the model can well reflect one-demensional consolidation and reological properties of clayey rock. The research could provide significant guidance for the planning, design, site selection, and operation of the high-level radioactive waste repository built in clayey rock in China in the future.