摘要
合理的土-锚界面蠕变模型是分析膨胀土锚固边坡蠕变特性和长期稳定性的关键。为研究土层灌浆锚杆锚固体与膨胀土界面剪切蠕变特性,利用自行研发的土-锚界面摩阻性能测试系统,通过瞬时剪切试验,得到了膨胀土-锚固体界面的瞬时剪切强度;同时,通过分级加载蠕变试验,得到了膨胀土-锚固体界面剪切蠕变全过程曲线,并根据“陈氏加载法”将分级加载曲线转化为分别加载曲线。基于试验结果,引入分数阶导数,结合Burgers模型,建立了描述膨胀土-锚固体界面蠕变过程的分数阶导数Burgers模型。采用建立的模型对蠕变试验结果进行拟合和预测,结果表明,该模型具有很好的拟合和预测效果。
The present paper is devoted to an evaluation of the creep property and long-term stability of the expanding soil anchorage, which is decisively dependent on the effectiveness and dependability of the creep model of the soil-anchored interface. For the research purpose, we have prepared 2 sets of samples with water content respectively of 19. 81% and 20. 08% by using the self-designed device so as to make an exploration of the creep specific features of the soil-anchored interface. The samples in each group of the two samples tend to be used for instantaneous shear test and the creep shear test respectively. And then, it is suggested to keep the sample in a sealed bag for 28 days to ensure for the anchor solid to reach the specified strength. Besides, it is suggested to devise a test system to test the soil-anchor interface friction resistance performance. And, then, the instantaneous shear test can help us to achieve the instantaneous shear strength of the soil-anchor interface. Then, the instantaneous shear strength can likely help us to gain the entire process shearing creep curves of the said soil-anchor interface. The step loading method can help us to divide the creep experiments into 6 -8 levels, while the real-time data of the displacement sensor can be collected and processed at all levels by the data acquisition instru- ment. In order to prevent the evaporation of water in the sample, it is necessary to seal up the exposed part of tile soil and the gap by vaseline that might cause water evaporation, so as to make the laboratory temperature basically constant. And, then, it would be possible to turn the entire process shearing creep curves into the creep curve at each specific loading level by using ＂Chen＇s method＂. Based on the results of the above experiments, the Burgers model can help to achieve better fitting effect, though the prediction effect can be rather poor. Therefore, to make up for the inef- ficiency, it would be necessary to introduce the fractional derivative and set up the frac
作者
陈昌富
高傑
刘俊斌
黄明华
CHEN Chang-fu;GAO Jie;LIU Jun-bin;HUANG Ming-hua(Institute of Geotechnical Engineering,Hunan University,Chan-gsha 410082,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2018年第5期1847-1854,共8页
Journal of Safety and Environment
基金
国家自然科学基金项目(41572298,51508180)
