| 吴成龙,苏占东*,夏京,何鑫洋.基于Felicity效应的砂岩损伤特性的试验研究[J].实验力学,2019,34(4):721~728 |
| 基于Felicity效应的砂岩损伤特性的试验研究 |
| Experimental study on damage characteristics of sandstone based on Felicity effect |
| 投稿时间：2018-09-06 修订日期：2018-11-03 |
| DOI：10.7520/1001-4888-18-205 |
| 中文关键词: 砂岩 冻融循环 振铃计数 Felicity比 损伤特性 |
| 英文关键词:sandstone freeze-thaw cycle ring-down counts Felicity ratio damage characteristics |
| 基金项目:教学研究与教学改革项目(JY2016B08)与国家自然科学基金(41807270)资助 |
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| 中文摘要: |
| 通过对砂岩试样进行冻融循环试验和冻融作用后岩石的单轴循环加卸载下的声发射试验，获取了岩石的抗冻性指标以及在各次冻融循环作用后砂岩试件的加卸载荷载、振铃计数与时间的关系，分析了岩石的抗冻性特点，重点对比了砂岩试件的Felicity比与岩石损伤的关系。研究结果表明：经历不同冻融循环次数砂岩试样的强度和质量均有所减小，体现了岩石试件冻融损伤由表及里的过程。冻融损伤砂岩试样在加卸载阶段都有明显的振铃计数产生，具有明显的Felicity效应。不同冻融循环次数下砂岩试样的Felicity比均小于1，且Felicity比随冻融循环次数的增加呈现不断减小的趋势，表明冻融循环次数的增加使砂岩内部具有的原始损伤加剧，Felicity比越来越小。随着循环加载次数的不断增加，砂岩试样的Felicity比整体呈现下降趋势，说明Felicity比可以同时反映出冻融作用和疲劳荷载对砂岩产生的损伤，该成果可为寒区岩体工程稳定性监测分析提供试验依据。 |
| 英文摘要: |
| Freeze-thaw cycle tests of sandstone samples and acoustic emission (AE) tests of different freeze-thaw injured rocks under uniaxial compression cycle loading and unloading conditions are carried out. The frost resistance index of rocks and the relationships of the loading and unloading on sandstone specimens, the ring-down counts with time after each freeze-thaw cycle are obtained.. The frost resistance characteristics of rocks are analyzed. The relationship between the Felicity ratio of sandstone specimens and rock damage characteristics is compared emphatically. The results show that the strength and quality of sandstone specimens are reduced after different freeze-thaw cycles, reflecting that the freezing and thawing damage of rock specimens experiences the process from the surface to the inside. The sandstone specimens after freeze-thaw damage have obvious ring-down counts during the loading and unloading stages, indicating obvious Felicity effect. The Felicity ratio of sandstone specimens under different freeze-thaw cycles is totally less than 1, and the Felicity ratio has a linearly negative correlation with the number of freeze-thaw cycles, indicating that the original damage degree of rocks increases and the Felicity ratio gets smaller and smaller with increasing the number of freeze-thaw cycles. As the number of cyclic loadings increases, the Felicity ratio of sandstone specimens will be reduced, indicating that the Felicity ratio can simultaneously reflect the damage to sandstone specimens caused by freeze-thaw and fatigue loads. This work would provide experimental guidance for monitoring and analyzing rock engineering stability in cold regions. |
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