西北地区富水岩层井筒建设多采用冻结法凿井，但部分井筒冻结壁解冻后井壁出现渗（淋）水，个别井筒甚至出现突水淹井事故，冻结法施工井筒水害频发，治理费用高昂且危及安全生产。关于冻结法施工井筒水害成因有两种不同解释，一是因冻结管周围环形空间导水产生水害；二是因围岩与井壁接触面冻融损伤导水产生水害。目前，由于针对水害成因的研究刚刚起步，水害发生机理尚不明确，导致井筒水害治理效果欠佳，井筒水害问题已成为影响西部地区矿井安全生产急需解决的技术难题。针对上述工程技术问题，本文以室内试验为基础，结合岩石力学、损伤力学理论，分别对白垩系砂岩、砂岩-砼组合体试件不同负温人工冻结（一次冻结融解）条件下，依次开展了扫描电镜试验、渗透率测试试验、物理力学试验和渗透系数测试试验，分别从微观结构损伤及其宏观表现两个角度，分析两种试件人工冻结致损及损伤变化情况，讨论了冻融损伤机理和影响冻融损伤的主要因素，进而分析井筒水害发生机理。主要研究内容及结果如下： （1）对冻结前和冻结融解后砂岩、砂岩-砼组合体试件分别开展了气测渗透率试验和扫描电镜试验。通过渗透率测试试验发现，组合体试件冻结前和冻结融解后平均渗透率均大于砂岩试件；两种试件冻结融解后平均渗透率与冻结前相比均有一定幅度的增加；组合体试件平均渗透率增长幅度大于砂岩试件；两种试件平均渗透率增长幅度均随着冻结温度的降低略有增大。通过微观扫描电镜试验结果发现，试件冻融前后表面微观孔隙发生了明显的变化，冻融后颗粒间空隙较冻融前大，试件表面的微裂纹明显扩展；砂岩-砼组合体试件接触面处空隙裂隙增加尤为明显。试验结果表明，人工冻结导致两种试件微观结构特别是组合体接触面受损，进而导致试件渗透率增大。 （2）对砂岩和砂岩-砼组合体试件在干燥、常温饱水状态以及经历不同冻结温度一次冻融后开展饱和吸水率试验和单轴压缩试验。实验结果表明：干燥状态下试件强度最大，饱水常温状态下次之，经历一次冻融循环后试件强度最低。冻结温度越低，饱和含水率越高，冻融循环作用对其弹性模量影响越大降低幅度越明显；由此可以说明，水能引起两种试件软化并使其强度大幅度降低，也是引起冻融损伤的的关键因素。两种试件的变形破坏过程是一致的，都依次经过了压密阶段、弹性阶段、塑性屈服阶段和破坏阶段，且两种试件的破坏形式均是以试件内部受拉伸破坏为主。组合体试件饱和吸水率对一次冻融循环敏感，其内部结构特别是接触面处受冻融作用引起的损伤大。 （3）对砂岩和砂岩-砼组合体试件开展了常温饱水状态以及不同冻结温度冻融后的渗透系数测试试验。由试验数据可知，常温下，砂岩渗透系数大于组合体渗透系数，砂岩的透水性较混凝土好，砂岩-砼试件接触面胶结密实。一次冻融后，两种试件渗透系数均有所增大；组合体渗透系数增大幅度大于砂岩试件；在冻结温度为-20℃和-30℃时，相比于-10℃冻结条件下渗透系数增长幅度不大；经历一次冻融后，组合体试件的渗透系数大于砂岩试件，说明冻融作用对组合体试件特别是接触面处的损伤较大。 （4）人工冻结法施工，井筒冻融损伤的主要因素有：围岩岩性、井壁支护体性质、接触面胶结程度、含水量和饱和度、冻结温度和应力状态等。从损伤变量的角度分析冻融前后两种试件经过一次冻融循环后损伤变化情况，在不同冻结温度（-10℃、-20℃、-30℃）条件下经过一次冻融循环后，先后从微观角度和宏观角度选取不同的参数作为损伤变量。数据共同说明，从损伤变量值来看，一次冻融循环对组合体试件造成损伤程度大于砂岩，两组试件在冻结温度为-30℃进行冻融后损伤最大，从损伤变量的变化幅度来看，试件经历一次冻融循环造成的损伤主要是在冻结温度为0℃~-20℃范围内完成的，宏观和微观角度选取损伤变量得出的结论是一致的。

Freezing shaft sinking method has been generally used in the mine construction of northwest area rich in water rock. But partial wellbores have the problem of leakage after freezing method of shaft construction thaw, individual wellbore even water irruption flooding accident. Freezing method construction of wellbore has caused frequent water disasters,and governance cost and high endangers the safety of production. On freezing method of shaft construction water disaster origin has two different interpretations, one is due to freezing tube annular space around a guide water flood; the other is that rock and wall contact surface freeze-thaw damage by water flood. At present, the research for the causes of water damage has just started, and the water damage mechanism is not clear, resulting in wellbore water hazard control effect is poor, wellbore damage problem has become the influence of western region and the safety in production of coal mine is badly in need of solving technical problems. According to the engineering technical problems, this paper on the indoor test as the basis, combined with rock mechanics, damage mechanics theory, respectively to Cretaceous sandstone and sandstone concrete combined test pieces with different temperature artificial freezing (a freezing and thawing) conditions, in order to carry out the scanning electron microscopy (SEM) test, permeability test, physical and mechanical tests and permeability coefficient test, respectively from the two angles of the damage microstructure and its macroscopic performance of the two specimens and artificial freezing induced changes of loss and damage, discusses the freeze-thaw damage mechanism and influencing freezing thawing damage mainly factors and analysis wellbore damage mechanism. The main research contents and results are as follows: (1) The results of permeability testing show that, test pieces of the combination before freezing and freezing and thawing after average permeability were stronger than that of sandstone specimens; the average permeability of two specimens have certain amplitude increase compared to freezing and thawing after and freezing front; the average permeability growth amplitude of combination test is bigger than that of sandstone specimens; two test average permeability increase slightly increased with the decrease of freezing temperatures. Through the scanning electron microscope test results found that specimens of freezing and thawing of obvious changes before and after surface micro pore and freeze thawing inter particle voids than freeze thaw before, pieces of the surface micro cracks could be extended; sandstone - concrete combination test pieces at the contact surface of the void fracture increase is particularly significant. The test results show that the artificial freezing leads to the damage of the micro structure of the two specimens, especially the contact surface of the composite, which leads to the increase of the permeability of the specimen. (2) The results of saturated water absorption test and uniaxial compression test show that the strength of the specimens under dry condition is the biggest, and that of saturated water at room temperature. The lower the freezing temperature, saturated water content is high, freezing and thawing cycle more serious influence on the elastic modulus decreased more significantly; this can explain, hydropower cause two specimen softening and its strength is reduced to a large extent, is caused by the freeze-thaw damage of the key factors. Two specimens of the deformation and failure process is consistent, in turn after the pressure dense stage, elastic stage, plastic stage and failure stage yielding and failure form of two specimens are to test the internal tensile failure is the main. Combination of saturation water absorption of a freeze-thaw cycle sensitive, its internal structure especially at the contact surface of the freezing and thawing caused damage in the experiment. (3) The results of the permeability coefficient test show that the permeability coefficient of sandstone is larger than that of composite permeability coefficient under normal temperature, and the permeability of sandstone is better than that of concrete. A after freezing and thawing, two specimen permeability coefficient were increased; the coefficient of permeability of combination increasing amplitude is bigger than that of sandstone specimens; the freezing temperature of -20℃ and -30℃ when compared to -10℃ for freezing conditions permeability coefficient increase greatly; experience a after freezing and thawing, the combination test of permeability coefficient is bigger than that of sandstone specimens that freezing and thawing of combination specimens especially contact surface damage is greater. (4) In artificial freezing method construction shaft, freezing thawing damage of main factors have: rock lithology, borehole supportings properties, contact surface and the degree of cementation, containing content and degree of saturation, the freezing temperature and stress state. From the point of view of the damage variable of freeze thaw before and after the two specimens after a freeze-thaw cycles damage change situation, in under the condition of the different freezing temperature (-10℃, - 20℃, - 30℃) after a freeze-thaw cycle, has from the microscopic and macroscopic view angles selected different parameters as the damage variable. Data show that, from the damage variable values, a freeze thaw cycles of specimens of combination caused damage to a greater extent than sandstone, two groups of specimens at the freezing temperature is - 30℃after the freeze-thaw damage maximum, from the point of view of the amplitude of damage variable, member through a cycle of freezing and thawing caused damage is mainly at the freezing temperature of 0℃~-20℃, macroscopic and microcosmic point of view selected damage variable that is consistent with the conclusion.