九甸峡堆石料三轴蠕变试验初探

Study on triaxial creep test for Jiudianxia rockfill materials

堆石料蠕变变形,是高土石坝设计中关注的主要问题之一,目前尚未很好解决。针对当前高土石坝的需要,采用大型高压三轴蠕变仪进行了堆石蠕变试验。通过试验,对堆石的三轴蠕变试验方法进行论述,并对堆石三轴蠕变试验中的蠕变时间起点、蠕变变形稳定标准进行了讨论,同时建议了三轴蠕变试验中蠕变时间起点和蠕变稳定的参考标准。试验结果表明,堆石的蠕变变形与围压及应力水平有关,特别在高围压、高应力水平作用下,蠕变稳定明显缓慢;在双对数坐标下,蠕变变形与时间呈较好的线性关系,且不同应力状态下的堆石蠕变规律基本相似。

The creep deformation of rockfill is a key problem in design of high earth rockfill dam,but it is not solved well so far. Using the large-scale high pressure triaxial creep apparatus,a number of tests on rockfill are carried out. The triaxial creep test method,the jumping-off point of creep and the creep deformation steady criteria are discussed,and at the same time the jumping-off point of creep and the creep deformation steady criteria are suggested. The test results show that the creep deformation for rockfill depend on confining pressure and stress level,especially in the high confining pressure and high stress level,the steady is slow in evidence. The relationship between creep deformation and time is linear in the log-log plot and the laws of the creep deformation are similar in different stress conditions.