人工冻结法是富水洛河组地层斜井施工的重要方法之一，开展西部冻结斜井类裂隙岩石解冻后蠕变力学特性试验研究对人工冻结斜井井筒解冻后的长期稳定性评价及矿井安全生产具有重要价值，本文以榆林市可可盖煤矿冻结斜井工程为依托开展研究工作。将可可盖煤矿洛河组砂岩作为原岩，利用相似材料制备的类裂隙岩石作为研究对象，采用试验研究与理论分析相结合的研究方法对类裂隙岩石解冻后三轴压缩试验下变形与破坏特征、解冻后类裂隙岩石蠕变力学特性进行研究。研究内容及结论如下：

(1)完成了陕北榆林洛河组砂岩X射线衍射分析试验及三轴压缩试验，依据相似定理及类岩石配比正交试验确定合理配比，使用相似材料制作含有不同裂隙倾角的类裂隙岩石，完成了类裂隙岩石不同冻结温度下的冻结-解冻试验。随着裂隙倾角增加解冻后冻胀力对试件造成的局部化损伤效应逐渐减弱；随着冻结温度的降低，试件顶部边缘剥落量逐渐增加，并且在预制裂隙尖端由初始损伤萌生的新裂纹数量及贯通程度都在增加。

(2)完成了不同冻结温度下类裂隙岩石解冻后三轴压缩试验。随着围压逐渐增加类裂隙岩石的力学性能在提高，破坏模式由劈裂破坏逐渐向沿着预制裂隙进行扩展的剪切滑移破坏过渡，类裂隙岩石次生主裂纹周围颗粒破碎情况有所减少，说明随着围压的逐渐增加，类裂隙岩石塑性增加。随着裂隙倾角的增加，类裂隙岩石力学性能先降低后增大，变化趋势呈现整体呈“U”型，在裂隙倾角为45°时力学性能最弱。随着冻结温度的逐渐降低，不同裂隙倾角类裂隙岩石解冻后力学性能随之降低，破坏后沿预制裂隙尖端产生裂纹数量增加。

(3)通过原状类裂隙岩石、解冻后类裂隙岩石及解冻后类裂隙岩石三轴压缩破坏后三种状态下的核磁共振试验，分析了三种状态下类裂隙岩石孔隙结构随裂隙裂隙倾角及冻结温度等因素的变化规律。结果表明，不同裂隙倾角原状类裂隙岩石在孔径分布范围为0-1μm内基本没有分布，主要的孔径分布范围在1-50μm，占总孔径的比例超过90%。解冻后类裂隙岩石T₂谱的分布出现一定程度的向右移动，随着裂隙倾角的逐渐增加新出现的波峰峰值逐渐降低。随着冻结温度的降低，T₂谱向右移动的同时还出现较为明显的第二波峰。三轴压缩破坏后T₂谱随着冻结温度的逐渐降低，向右移动逐渐明显，出现了峰值逐渐增加的第三个波峰且裂隙倾角为45°时大孔径孔隙增加程度最大。

(4)完成了不同冻结温度下不同裂隙倾角类裂隙岩石解冻后分级加载三轴压缩蠕变试验。随着裂隙倾角的逐渐增加总蠕变量先增大后减小，裂隙倾角为45°时蠕变速率变化最快。随着冻结温度的降低，造成试件初始损伤增加，导致各蠕变应力水平下轴向蠕变量及蠕变速率相应增加。随着荷载等级的不断提高，岩石进入稳定蠕变阶段所经历的时间越长，粘滞性越明显。类裂隙岩石试件的蠕变破坏模式与三轴压缩条件下的破坏模式基本相同。随着冻结温度的降低，不同裂隙倾角类裂隙岩石次生主裂纹越来越多，破坏现象越来越显著。

(5)通过原状类裂隙岩石、解冻后类裂隙岩石及解冻后类裂隙岩石三轴压缩蠕变破坏后三种状态核磁共振试验，分析了三种状态下类裂隙岩石孔隙结构随裂隙倾角及冻结温度等因素的变化规律。结果表明，原状类裂隙岩石及解冻后类裂隙岩石T₂谱及孔隙分布情况与三轴常规压缩条件下规律相似。三轴压缩蠕变破坏后与三轴压缩破坏后相比，类裂隙岩石核磁共振信号强度增加且向右移动更加明显，裂隙倾角为45°时类裂隙岩石向右移动最明显。第一峰面积所占总面积比例有所降低，第二峰及第三峰面积和所占总面积比例有所增加。裂隙倾角为45°时类裂隙岩石在长期荷载作用下宏观蠕变力学性能的总蠕变量及加速阶段蠕变速率最大，对应破坏后谱面积也是最大的。

(6)通过引入裂隙岩石塑性体元件及时效劣化因子来改进西原体蠕变模型，构成考虑原生节理影响的非线性蠕变模型。根据三轴分级加载蠕变试验数据对蠕变模型进行拟合验证，拟合结果与试验数据基本吻合。

The artificial freezing method is one of the important methods for the construction of inclined wells in the Fushui Luohe Formation. Carrying out the experimental study on the creep mechanical properties of the single-fractured rock in the frozen inclined wells in the western region is of great value to the long-term stability evaluation of the artificially frozen inclined shaft after thawing and the mine safety production. This paper relies on the frozen inclined shaft project of the KeKeGai Coal Mine in Yulin City to carry out research work. The sandstone of Luohe Formation in Cocoa Cover Coal Mine was used as the original rock. Fractured rocks containing single prefabricated fractures with different dip angles were prepared as the research object. The research method combining experimental research and theoretical analysis was used to study the deformation and failure characteristics of fracture-like rock under the conventional triaxial compression test after thawing, and the creep mechanical properties of fracture-like rock after thawing. The main research contents and conclusions are as follows:

(1) The sandstone X-ray diffraction analysis test and conventional triaxial compression test of Luohe Formation in Yulin, Northern Shaanxi were completed. According to the similarity theorem and rock-like ratio orthogonal test, the reasonable ratio was determined. Use similar materials to make fractured rocks with different inclination angles. The freeze-thaw test under different freezing temperatures of fractured rocks was completed. With the increase of the inclination angle, the localized damage effect caused by the frost heaving force on the specimen gradually weakened. As the freezing temperature decreased, the amount of peeling off the top edge of the test piece gradually increased. And the number and penetration of new cracks that originated from the initial damage at the tip of the prefabricated crack are increasing.

(2) The conventional triaxial compression test after the thawing of single-fractured rocks at different freezing temperatures was completed. As the confining pressure gradually increased, the failure mode gradually changed from cleavage failure to shear-slip failure that extended along the prefabricated crack. Moreover, the particle breakage around the secondary primary cracks in fractured rocks had improved. This showed that with the gradual increase of confining pressure, the plasticity of fractured rock increases. As the dip angle increased, the mechanical properties of fractured rock decreased first and then increased. The change trend presents an overall "U" shape. The mechanical properties were weakest when the inclination angle was 45°. With the gradual decrease of the freezing temperature, the mechanical properties of the fractured rocks at all inclination angles after thawing decrease. After the failure, the number of cracks along the tip of the prefabricated cracks increased, and the cracks developed more fully under the effect of partial stress.

(3) The nuclear magnetic resonance test was carried out in three states after triaxial compression failure of undisturbed single-fractured rock, single-fractured rock after thawing and single-fractured rock after thawing. The changes of the pore structure of the fractured rock with the fracture dip angle and freezing temperature and other factors were analyzed in the three states. The results showed that the intact fissured rocks at all dip angles had almost no distribution in the pore size distribution range of 0-1 μm. The main pore size distribution ranged from 1-50 μm. The proportion of the total pore diameter exceeds 90%. After thawing, the distribution of the T₂ spectrum of the fractured rock shifted to the right to a certain extent, and the newly-increased peaks and peaks gradually decreased as the dip angle gradually increased. As the freezing temperature decreased, the T₂ spectrum moved to the right and a more obvious second peak appears. After the triaxial compression failure of the fractured rock, the T₂ spectrum gradually decreased with the freezing temperature and gradually moved to the right. And there was a third peak with increasing peak value and the largest increase in pore size was when the inclination angle was 45°.

(4) Triaxial compression creep test after thawing of single-fractured rocks with different inclination angles at different freezing temperatures was completed. As the inclination angle gradually increased, the total creep increases first and then decreased. When the inclination angle was 45°, the creep rate changed fastest. As the freezing temperature decreased, the initial damage of the specimen increased, resulting in a corresponding increase in axial creep and creep rate at each creep stress level. With the continuous improvement of the load level, the longer the time it took for the rock to enter the stage of stable creep, the more obvious the viscosity. The creep failure mode of fractured rock specimens was basically the same as that under conventional triaxial compression. However, compared with the conventional triaxial compression state, the particles around the generated secondary primary cracks were not so broken. With the gradual decrease of the freezing temperature, the damage degree of the fractured rock at each dip angle was increasing, and multiple secondary primary cracks were generated.

(5) Through three-state nuclear magnetic resonance tests of undisturbed single-fractured rock, thawed single-fractured rock and thawed single-fractured rock after triaxial compression failure. Analyze the variation law of the fractured rock pore structure with the fracture dip angle, confining pressure and freezing temperature under the three conditions. The results showed that the T₂ spectrum and pore distribution of undisturbed single-fractured rock and single-fractured rock after thawing are similar to those under triaxial conventional compression. Compared with the conventional triaxial compression failure after the triaxial compression creep failure, the nuclear magnetic resonance signal strength of the fractured rock increased and the movement to the right was more obvious. When the dip angle was 45°, the fractured rock moves to the right most obviously. The ratio of the area of the first peak to the total area had decreased, and the area of the second and third peaks had increased. When the inclination angle was 45°, the total creep of the macroscopic creep mechanical properties of the fractured rock under the long-term load and the creep rate in the acceleration phase are the largest, and the corresponding spectral area was also the largest after the failure.

(6) The creep model of N. pisiformis was improved by introducing the plastic elements of fissured rock and the time-deterioration factor to form a nonlinear creep model considering the influence of the original joints. According to the creep test data of triaxial hierarchical loading, the creep model was fitted and verified, and the fitting result was basically consistent with the test data.