| 裂隙岩体循环冻融变形特征及影响因素分析 |
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| 引用本文： | 崔圣华,杨晴雯,芮雪莲,张御阳.裂隙岩体循环冻融变形特征及影响因素分析[J].地质科技通报,2021,40(6):205-215. |
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| 作者姓名： | 崔圣华 杨晴雯 芮雪莲 张御阳 |
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| 基金项目： | 国家创新研究群体科学基金项目41521002国家自然科学基金项目41907254国家自然科学基金项目41931296 |
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| 摘 要： | 高寒、高海拔地区由于反复冻融导致的岩体变形破坏，对区内工程建设有重大影响。为研究不同裂隙条件下岩体循环冻融特性，在汶马高速沿线选择具有代表性的千枚岩和砂岩，制备了不同裂隙条件（长度、张开度、裂隙组数）试样，在干燥和饱水两种状态下分别进行大温差（-20℃到20℃）循环冻融（50次）试验。试验揭示了饱水裂隙岩样冻融变形过程:冻缩→冻胀→冻缩（冻结阶段）→融胀→融缩→融胀（融化阶段），干燥裂隙岩样冻融变形过程:冻缩（冻结阶段）→融胀（融化阶段）。进一步，选择冻胀量εd为指标，分析了两类岩样冻融循环次数与εd的关系，揭示了裂隙长度、宽度和组数对εr的影响规律；选择残余变形量εr为指标，揭示了千枚岩和砂岩试样在饱水条件下εr随εd的增加规律，获得了εd与εr间的定量关系；分析了干燥和饱水试样单轴抗压强度随冻融循环次数增加而减小规律，确定了冻融次数与试样劣化间的线性关系。最后，初步讨论了饱水条件、岩性和裂隙条件对岩体冻融循环变形的影响机制。
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| 关 键 词： | 裂隙岩体 冻融循环 冻胀量 残余应变 |
| 收稿时间： | 2021-03-03 |
Effect factors analysis and characteristic of freeze-thaw deformation of fracture rock |
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| Abstract: | In the cold and high-altitude regions of Sichuan Provence, the rock failure caused by freeze-thaw deformation has a significant impact on projects. In order to study the cyclic freeze-thaw characteristics of rock mass under different fracture conditions, the phyllite and sandstone were taken from this area. The rock samples with different joint lengths, opening, number of joints were conducted with 50 cycles of freeze-thaw tests under ±20℃. The test results showed that the saturated rock had process of freeze contract→freeze expand→freeze contract→thaw expand→thaw contract→thaw expand. The dry rock had process of freeze contract→melt expansion. The relationship between freeze-thaw cycle times and εd was studied. The length of joint, opening and number of joints had an influence on freeze-thaw deformation of dry sample. Select the residual deformation εr as an index to study the increasing of εr with increasing of εd for phyllite and sandstone samples under the water saturation conditions. The relationship between εr and εd had been obtained. The decreasing of uniaxial compressive strength of dry and saturated samples with increasing of the number of freeze-thaw cycles was analyzed. The linear relationship between freeze-thaw times and sample deterioration was determined. Finally, the influence mechanisms of water saturation condition, lithology and fracture condition on freeze-thaw cyclic deformation of rock mass were discussed. |
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