为探讨富水充填材料稳定性与时间的关系及其在荷载作用下的失稳破坏特征与损伤发展规律,文中制备了一定水固比的富水充填材料,通过蠕变试验对不同应力水平下富水充填材料的蠕变性能进行测试,研究蠕变过程中应变速率衰减、稳定及加速3个蠕变阶段应变随时间的变化特征,提出充填体失稳的临界荷载。根据蠕变试验数据,引入损伤变量,建立符合富水充填材料的蠕变损伤模型,推导出应力、应变、时间及损伤因子等力学参量之间的相关关系。结果表明:水固比2.0的富水充填材料失稳破坏的临界荷载为其强度的90%;改进后的Burgers模型,综合考虑了蠕变参数受时间和应力水平的影响,反映了参数随时间弱化的现象,拟合后发现该模型可以描述富水充填材料失稳破坏前的损伤劣化规律。

In order to investigate the relationship between stability and time,and the failure characteristics and damage development rule of rich-water packing material under load,the rich-water packing material with a certain water-solid ratio was prepared in this study. The creep property of rich-water packing material in different stress levels was studied by creep experiment. The deformation characteristics of stain change with time during the creep process which could be divided into three stages,attenuation,steady and acceleration were analyzed. The critical load of packing body instabil- ity was presented. The creep damage model for rich-water packing material was established by introducing damage var- iable based creep test data. The relationships of mechanic parameters among stress,stain,time,damage factor and so on were deduced. The results show that the failure critical load of rich-water packing material with water-solid ratio 2． 0 is 90% of its compressive strength. The improved Burgers model considered the influence of time and stress on creep parameters and reflected the weakening of parameters with time. The study shows that the model could be used to describe the damage deterioration rule of rich-water packing material before failure by fitting.