深部富水软弱岩层立井冻结工程稳定机理与冷能优化研究

Since the mesozoic stratums' complicated physical and mechanics characteristics, such as late diagenesis, loose, soft, water induced mudding and sanding, recently, the coalmine shaft submergence and wall collapase failure occurred frequently in shafts construction with freezing method in this stratum. Therefore, it is necessary to study the reliability and stability of shaft freezing technology in water-rich weak mesozoic stratum in deep coal mine construction engineering. In order to disclose the macro-mesocopic thermal and mechanics characteristic, failure law and characterization method for frozen rocks, the coupling effect of water, temperature and confining pressure on thermal-physical and mechanics properties for frozen rock are researched by a series lab tests such as real time CT meso-mechanics experiment, thermology experiment, microstructural evolution tests in process of freezing and thawing, tri-axial creep tests with high confining pressure. On the basis of the field monitoring and measurement on a practical mine construction project in China northen-west area, the 3D-scale modeling shaft experiments in frozen soft rocks are carried out to investigate the development law and influencing factor of frozen-rock wall. The deformation and failure law of frozen soft rock wall will be ascertained with further studies. Focused on the heat conduction differentiation of stratum, a newly patented technique for partially artificial freezing device in different depth is developed and studied, which can strengthen freezing the specified stratums by providing cold energy in different freezing level according the stratum "freezing energy" requirement. This research will provide the key theoretical proofs and experiment supports for constructing coalmine shafts with artificial freezing method in water-rich soft weak mesozoic stratums.

我国西北中生代含煤地层成岩晚、岩石松软、遇水泥化砂化、导水性好，加之研究不足，近期此类地层立井冻结工程已发生多起严重淹井和垮塌事故，急需研究富水软弱岩层立井冻结可靠性及稳定性控制难题。采用最新工业CT细观热-力学试验手段等，进行富水软弱冻岩细观CT实时力学试验、热学实验及冻融过程细观结构演化试验、高围压三轴蠕变实验等；研究热-力耦合下水分、温度和围压对冻岩热学-力学性质影响；揭示水-热-力耦合下冻岩的细宏观热学-力学特征、破坏规律及表征方法。结合西北典型立井冻结工程实例, 进行软弱冻岩段立井三维模型实验，弄清软弱岩层冻结壁发展的影响因素及规律；探明富含水、高水头、高围压不利工况下软弱岩层冻结失效机理；获得立井开挖卸荷作用下软弱岩层冻结壁变形破坏规律。针对不同地层导热差异性，开发可变深度局部冻结新技术，实现地层强化冻结及冷能优化，为解决软弱岩层立井冻结凿井难题提供重要的试验依据与理论支持。

我国西北中生代含煤地层成岩晚、岩石松软、遇水泥化砂化、导水性好，加之研究不足，近期此类地层立井冻结工程已发生多起严重淹井和垮塌事故，急需研究富水软弱岩层立井冻结可靠性及稳定性控制难题。采用最新工业CT细观热-力学试验手段等，进行富水软弱冻岩细观CT实时力学试验、热学实验及冻融过程细观结构演化试验、高围压三轴蠕变实验等；研究热-力耦合下水分、温度和围压对冻岩热学-力学性质影响；揭示水-热-力耦合下冻岩的细宏观热学-力学特征、破坏规律及表征方法。结合西北典型立井冻结工程实例, 进行软弱冻岩段立井三维模型实验，弄清软弱岩层冻结壁发展的影响因素及规律；探明富含水、高水头、高围压不利工况下软弱岩层冻结失效机理；获得立井开挖卸荷作用下软弱岩层冻结壁变形破坏规律。针对不同地层导热差异性，开发可变深度局部冻结新技术，实现地层强化冻结及冷能优化，为解决软弱岩层立井冻结凿井难题提供重要的试验依据与理论支持。. 基于该项目共发表论文22篇，其中EI检索13篇，核心期刊9篇。在项目执行期间，开展国内外学术交流14次。根据阶段性研究成果，在国际学术会议上做大会报告6次，其中在德国做特邀报告1次，国内学术交流会议上做大会邀请报告1次。邀请国外访问学者与开展国际合作研究7次。共计获得4项知识产权成果：研发了2项发明专利，1项实用新型专利，1项计算机软件著作权已应用于工程实际。共获得省部级奖励5项。其中获得省部级科技进步奖3项，其中一等奖1项（排名第8），二等奖2项（均排名第6）。北京市教学奖2项（均排名第1）。1项发明专利成果已经进行了技术转让，并应用于工程建设实际。在研期间，获得省部级以上人才支持计划或荣誉称号6项。基于该项目培养硕士2名，博士3名。按期完成研究任务。