| With the increasing development depth of resources,the hydrogeological conditions of the vertical shaft crossing the stratum are becoming more and more complex.In view of the technical and economic challenges faced by the freezing project of the air intake shaft of Gaojiapu coal mine,the deepest freezing shaft at home and abroad,the whole field monitoring theory research based on modern sensing and information technology is determined to improve the reliability and theoretical level of the deep vertical shaft freezing project.This paper has carried out the following research.(1)Taking the development of freezing depth as the coordinate,the development history and existing problems of shaft freezing temperature field theory and temperature field monitoring technology are studied.A theoretical research on deep shaft freezing engineering technology based on the key technology control of freezing wall intersection and freezing wall forming and bearing is proposed.(2)The typical accident cases at home and abroad in the history of shaft freezing are studied.Based on the freezing construction process,accident investigation and engineering detection,the research direction of accident risk identification based on the transient temperature field in the shaft freezing process is proposed.(3)Based on the analytical theory,the transient heat transfer law of the freezing wall with the freezing apparatus as the center under the condition of freezing interruption is studied.Based on the consistency of model experiment and numerical analysis,the influencing factors and basic laws of the theory of the transient temperature rise in the center of the freezing apparatus are studied,including the influence of groundwater flow,original ground temperature,salt water flow and salt water temperature on the determination of the state of the freezing wall.(4)Based on the theoretical results of transient temperature field research,compared with the theoretical and technical limitations of the steady-state temperature monitoring with the traditional temperature measuring hole as the main body,the theoretical framework of the whole field monitoring of the freezing wall temperature field based on the development of the longitudinal one-line temperature measurement technology is established,and the whole field control theory and method of the three-stage division of the shaft freezing project are proposed.(5)The time series theory,grey analysis model,BP network and other modern data mining theories are creatively applied to the whole field monitoring process of the freezing wall.A mathematical model for monitoring the intersection time of shaft freezing wall is proposed to predict and control the intersection time of freezing wall.The problem of judging the position and size of freezing wall window is solved.The prediction results are basically consistent with the measured results,and the prediction method has high accuracy.(6)The research takes the stragity and route of one-line bus temperature survey technology based on the digital sensor,adopts the high-performance single chip microcomputer,the enhanced steady current driving circuit,the level self-detection technology,and develops the super driven temperature acquisition module with the structure of pull-up resistance and pull-down resistance and the continuous distributed digital temperature measurement cable,which solves the key technology of over kilometer Temperature survey and full loading sensors.(7)Taking the Gaojiabao 990m air inlet shaft freezing project as an example,new theories,new technologies and new process practices were carried out,and the project objectives and model tests were successfully achieved.Therefore,it can provide reference materials for the further development of the research and development of the deep vertical shaft full-field monitoring theory with the longitudinal temperature measurement of the 1-wire bus as the key technology. |
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