人工冻结法是西部富水洛河组砂岩地层煤矿斜井的重要施工方法之一，开展冻结斜井洛河组砂岩解冻后蠕变损伤破坏机理研究对冻结斜井井筒的灾害发生机理分析与长期稳定性评价具有重要的理论和工程价值。本文以可可盖煤矿人工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研究对象，采用试验研究与理论分析相结合的方法对洛河组砂岩解冻后三轴压缩变形与破坏特征、三轴压缩蠕变力学特性进行了研究。主要内容与结论如下：

（1）以洛河组砂岩为研究对象，采用X-光谱衍射方法分析了砂岩的组成成份，完成了砂岩初始状态下的物理力学参数测定。对砂岩的孔隙性、胶结程度及水理性质进行了评价。采用GCTS电液伺服控制高低温高压岩石三轴测试系统对砂岩开展了不同围压下的三轴压缩试验，分析了砂岩的三轴压缩变形规律与强度劣化特征。

（2）通过室内冻结-解冻后的物理试验得到岩样的质量损失率、波速损失率等物理参数。完成了砂岩解冻后三轴压缩试验，结果表明，随着围压的增加，砂岩的承载力逐渐提高，砂岩破坏时轴向应变逐渐增加，砂岩的弹性模量与变形模量逐渐提高，泊松比逐渐减小。随着冻结温度的降低，砂岩的粘聚力逐渐降低，砂岩结构弱化，内摩擦角有所减小，冻结温度对内摩擦角的影响不明显。随着围压的增大，砂岩的主破裂裂缝角度逐渐减小，次生裂纹逐渐增多，砂岩破坏程度更加严重，砂岩的主破裂裂缝宽度有所增大，砂岩破裂后出现明显的剥落现象。

（3）采用TAW-1000微机控制高温三轴蠕变试验机完成了不同冻结温度下解冻后砂岩在不同围压下的三轴压缩蠕变力学试验。结果表明，随着冻结温度的不断降低，每一级荷载作用下砂岩蠕变量逐渐增大，且砂岩最大蠕变量随冻结温度的降低逐渐增大，且呈现线性增长的趋势，说明冻结温度的降低导致砂岩内部损伤增多，相同荷载作用下更容易破坏。砂岩轴向最大变形量随围压的升高逐步增大，但增大幅度有所减小。砂岩等速蠕变阶段蠕变速率随围压的增大而减小，加速蠕变阶段蠕变速率随围压的增大而增大。解冻后洛河组砂岩呈现非线性蠕变力学特征，非线性程度与蠕变时间、砂岩所受应力水平及冻结温度均有关系，蠕变加载时间越长，荷载应力水平越大，冻结温度越低，砂岩的非线性程度越高。

（4）完成了砂岩原状样、解冻后砂岩、解冻后砂岩三轴压缩破坏后及解冻后砂岩三轴压缩蠕变破坏后的核磁共振试验，分析了砂岩的孔隙结构变化规律。结果表明，洛河组砂岩T₂分布谱主要存在三个峰图，孔隙粒径分布范围跨度较大，大部分孔径分布在10～500 范围内，表明洛河组砂岩为大孔隙砂岩。当冻结温度较高时，由于冻胀力的作用造成岩石产生微小孔隙。随着冻结温度的降低，洛河组砂岩原有孔隙进一步演化、扩展、贯通。洛河组砂岩在三轴压缩破坏后T₂分布谱第一峰值有所增大，且逐渐向右移动，第二峰值减小，向左移动，第三峰值增大明显，且向右移动。孔隙孔径在1～100 、1000～10000范围内的孔隙数量增多。解冻后砂岩三轴压缩蠕变破坏后大孔隙明显增多，砂岩原有及新萌生的微小孔隙在长期荷载作用下扩展，砂岩岩样破坏时，已有孔隙贯通为裂纹。

（5）基于分数阶微积分理论对洛河组砂岩解冻后三轴压缩蠕变试验数据进行了分析，构建了分数阶黏壶与含损伤的变阶分数阶黏壶，建立了解冻后砂岩的分数阶非线性粘弹塑性一维蠕变模型，并在此基础上构建了三维蠕变模型。采用最小二乘法，分别对不同冻结温度下单轴压缩蠕变特性以及同一冻结温度下、不同围压时三轴压缩蠕变特性的砂岩分数阶蠕变模型数据进行了拟合计算，理论模型与试验曲线基本吻合。

The artificial freezing method is one of the important construction methods for the inclined shaft of coal mines in the Fushui Luohe Formation sandstone stratum in the west. The research on the mechanism of creep damage and destruction of the frozen inclined shaft Luohe Formation sandstone after thawing Sexual evaluation has important theoretical and engineering value. In this paper, the combination of experimental research and theoretical analysis was used to study the triaxial compression deformation and failure characteristics, triaxial compression creep mechanical properties and the establishment of a nonlinear fractional creep mechanical model after thawing of the Luohe Formation sandstone. The main research contents and conclusions are as follows:

 (1) Taking the sandstone of Luohe Formation as the research object, the composition of sandstone was analyzed by X-spectral diffraction method, and the physical and mechanical parameters in the initial state of sandstone were completed. The porosity, cementation degree and hydraulic properties of sandstone were evaluated. The triaxial compression test of sandstone was carried out by GCTS electro-hydraulic servo control high and low temperature and high pressure rock triaxial test system. The deformation law and strength deterioration characteristics of the sandstone were analyzed, and the basic mechanical parameters of the Luohe Formation sandstone under different confining pressures were obtained.

(2) The physical property parameters such as the mass loss rate and wave velocity loss rate of the rock sample are obtained through the indoor freeze-thaw physical test. The triaxial compression test after the thawing of sandstone was completed. The results showed that with the increase of confining pressure, the bearing stress of sandstone gradually increased, and the peak axial strain of sandstone also increased. The elastic modulus and deformation modulus of sandstone gradually increased, and the Poisson's ratio gradually decreased. As the freezing temperature decreased, the cohesion of the sandstone gradually decreased, the sandstone structure weakens, and the internal friction angle decreased, but the effect of the freezing temperature was not obvious. The angle of sandstone's primary fractures gradually decreased, secondary fractures gradually increased, and the degree of sandstone damage was more serious. Not only the width of the sandstone's primary fractures increased, but there was obvious flaking after sandstone fracture.

(3) The high-temperature triaxial creep test machine controlled by TAW-1000 microcomputer was used to complete the triaxial compression creep test of sandstone under different confining pressures after thawing at different freezing temperatures. The results showed that as the freezing temperature continues to decrease, the creep of sandstone gradually increases under each load, and the maximum deformation of sandstone gradually increased as the freezing temperature decreased, and showed a linear growth trend, indicating that the freezing temperature The reduction lead to increased internal damage of the sandstone, and it was easier to break under the same load. The maximum axial deformation of sandstone gradually increased with the increase of confining pressure, but the increase was somewhat reduced. The creep rate of sandstone during the constant velocity creep phase decreases with the increase of confining pressure, but the creep rate of accelerated creep stage increases with the increase of confining pressure. After thawing, the Luohe Formation sandstone has nonlinear creep mechanical characteristics, and the degree of nonlinearity was related to the test creep time, the stress level of the sandstone and the freezing temperature. The longer the creep loading time, the greater the load stress level. The lower the freezing temperature, the higher nonlinearity of the sandstone.

(4) Completed the NMR test of the original state of the sandstone, the unfrozen sandstone, the unfrozen sandstone after triaxial compression failure and the unfrozen sandstone after triaxial creep compression failure, and analyzed the changes of the pore structure of the sandstone. The results showed that the Luohe River There are three main peaks in the T₂ distribution spectrum of the sandstones of the Formation. The pore size distribution range was large, and most of the pore size distributions were in the range of 10-500, indicating that the Luohe Formation sandstones are large-pore sandstones. When the freezing temperature is high, the micro-pores are generated in the rock due to the effect of frost heave force, but it has not been fully developed. As the freezing temperature decreases, the original pores inside the pores further crack, expand, and penetrate. After triaxial compression failure of the Luohe Formation sandstone, the first peak of the T₂ distribution spectrum has increased and gradually moved to the right, the second peak has decreased and moved to the left, and the third peak has increased significantly and moved to the right. The number of pores with pore diameters in the range of 1-100 and 1000-10000 increases. After thawing, the large pores of sandstone increased significantly after triaxial creep compression. The original and newly added small pores of the sandstone expanded to large pores due to the long-term load.

(5) Based on the fractional calculus theory, the triaxial compression creep test data of the Luohe Formation sandstone after thawing was analyzed, and the fractional-order clay pot and the variable-order fractional-order clay pot with damage were constructed. Fractional nonlinear viscoelastic-plastic one-dimensional creep model, and on this basis, a three-dimensional creep model is constructed. The least square method was used to fit the uniaxial creep under different freezing temperatures and the data of the sandstone fractional creep model under different confining pressures, and the corresponding parameters in the model were determined. The model and experiment The curves are basically consistent.