VISCOUS BEHAVIOUR OF GEOGRIDS; EXPERIMENT AND SIMULATION
VISCOUS BEHAVIOUR OF GEOGRIDS; EXPERIMENT AND SIMULATION
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DOI：
10.3208/sandf.47.265
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发表时间：
2007-04
影响因子：
3.7
通讯作者：
W. Kongkitkul;D. Hirakawa;F. Tatsuoka
中科院分区：
文献类型：
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作者：
W. Kongkitkul;D. Hirakawa;F. Tatsuoka
三种类型的土工格栅聚合物的粘性性能进行了评估，持续30天的负载水平约一半的标称断裂强度的持续加载测试。持续加载测试在恒定应变或加载速率下的单调加载（ML）期间进行，这与常规蠕变测试不同，在常规蠕变测试中，控制蠕变应变速率的持续加载开始之前的应变速率不受控制或甚至不记录。本研究报告介绍了以下内容。在30天的持续加载后开始的ML测量的拉伸断裂强度基本上与在相同应变速率下通过连续ML获得的拉伸断裂强度相同，而没有任何持续加载的间歇。这一事实表明，蠕变不是一种退化现象。然后，如果没有化学和机械降解效应，则土工合成加固件的强度（对于断裂时的给定应变率）可以保持到其使用寿命的后期。一个非线性的三组分模型被用来模拟从以前和现在的研究的实验结果。该模型不仅可以很好地模拟ML期间的负载-应变行为与不阶跃变化的应变速率和一个持续加载后，但也在持续加载过程中的蠕变应变的时间历程短（1小时）和长（30天）期间。
The viscous properties of three types of geogrid polymer were evaluated by sustained loading tests lasting for 30 days at a load level about a half of its nominal rupture strength. The sustained loading tests were performed during otherwise monotonic loading (ML) at constant strain or load rate, unlike the conventional creep tests, in which the strain rate immediately before the start of sustained loading, which controls the creep strain rate, is not controlled or even not recorded. The following are presented in this study. The tensile rupture strength measured by ML that was started following a 30 day-long sustained loading was essentially the same as the one at the same strain rate at rupture obtained by continuous ML without any intermission of sustained loading. This fact indicates that creep is not a degrading phenomenon. Then, if free from chemical and mechanical degrading effects, the strength of a geosynthetic reinforcement (for a given strain rate at rupture) can be maintained until late in its service life. A non-linear three-component model is used to simulate the experimental results from the previous and present studies. The model can simulate very well not only the load-strain behaviour during ML with and without step changes in the strain rate and the one after sustained loading, but also the time histories of creep strain during sustained loading for short (one hour) and long (30 days) periods.