深厚冲积层冻结孔布置分类技术对冻结调控的影响  

Classified arrangement technology of freezing holes in deep and thick alluvium and its influence on freezing control

作　　者：李功洲 李小伟[3] 陈红蕾 李方政[2] 彭飞[2] LI Gongzhou;LI Xiaowei;CHEN Honglei;LI Fangzheng;PENG Fei(China Electronics Engineering Design Institute Co.,Ltd.,State Development and Investment Corp.,Ltd.,Beijing 100142,China;Branch Institute of Mine Construction,China Coal Research Institute,Beijing 100013,China;Henan Guolong Mining Construction Co.,Ltd.,Zhengzhou 450000,China)

机构地区：[1]国家开发投资集团有限公司中国电子工程设计院有限公司,北京100142 [2]煤炭科学研究总院建井研究分院,北京100013 [3]河南国龙矿业建设有限公司,河南郑州450000

出　　处：《煤炭科学技术》2020年第12期31-38,共8页Coal Science and Technology

基　　金：国家自然科学基金资助项目(51774283)。

摘　　要：冻结孔布置方式不仅决定了能否按期形成设计所需的冻结壁有效厚度和平均温度,还会影响冻结法凿井的速度、安全和施工成本。不合适的布置方式甚至会成为冻结法凿井的安全隐患,因此冻结孔布置方式及其冻结壁形成特性一直是冻结法凿井的理论和技术研究热点和难点。提出深厚冲积层冻结孔按主冻结孔、辅助冻结孔、防片冻结孔3类功能分类设计和布置,可较好地解决主冻结孔及冻结壁主体结构的安全和稳定;根据冻结壁厚度需要及冻结时间均匀布置辅助孔,可明显减少辅助孔数量,提高冻结壁的均匀性和稳定性;根据挖掘荒径变化布置多圈防片孔,可提高冻结调控的灵活性和效果。工程实践表明:以外圈为主冻结孔的布孔方法,有利于主冻结孔和整体冻结壁的安全稳定,可减少冻结孔数量、钻孔工程量、冻结需冷量,提高了冻结的可调性和调控效果,推荐为深厚冲积层冻结孔布置方式的首选。合理的冻结孔布置可为冻结壁安全稳定及冻结调控打下良好的基础,施工过程中通过建立冻结壁形成特性实测分析、工程预报与冻结调控的机制,定期对冻结壁有效厚度、平均温度和井帮温度发展趋势进行分析和预测,提前对防片孔和辅助孔盐水流量、温度进行调控,甚至停止盐水循环,能有效控制井帮温度及冻土扩入荒径量,为掘砌施工创造良好条件。国内外冲积层厚度最大之一的赵固二矿西风井通过采用以外圈为主冻结孔的布孔方式,总的冻结孔数、冻结钻孔工程量、冻结需冷量均显著降低,且冻结壁内部温度和强度的均匀性更好;结合黏性土层井帮稳定性观测,通过主动调控,实现400 m以深井帮温度还可略高于设计调控目标,635 m以深井帮温度接近设计调控目标,冻结壁厚度和平均温度始终满足设计要求,冲积层深部黏性土层井帮温度控制在-11℃以上,砂性土层井�The arrangement of freezing holes not only determines whether the effective thickness and average temperature of the freezing wall required by the design can be formed on schedule,but also directly affects the speed,safety and construction cost of the freezing shaft sinking.Improper arrangement will even become the hidden danger.Therefore,the arrangement of freezing holes and formation characteristics of freezing wall are always the hot and difficult points in theory and technology research.The design and arrangement of freezing holes in deep and thick alluvium can be classified into three types:main freezing hole,auxiliary freezing hole and spalling-prevention freezing hole,which can solve the problems of safety and stability of main structure of main freezing hole and freezing wall.Arranging auxiliary holes evenly according to the thickness of frozen wall and freezing time can obviously reduce the number of auxiliary holes and improve the uniformity and stability of the freezing wall.The flexibility and effect of freezing control can be improved by arranging multiple circles of spalling-prevention freezing holes according to the change of excavation diameter.The engineering practice shows that the holes arrangement method with outer ring as the main freezing hole is beneficial to the safety and stability of the main freezing hole and the overall freezing wall,which can reduce the number of freezing holes,the work amount of drilling holes and the cooling capacity required,improve the adjustability and control effect of freezing,and is recommended as the first choice for the arrangement of freezing holes in deep and thick alluvium.The reasonable arrangement of freezing holes can lay a good foundation for the safety and stability of the freezing wall and the control of freezing.In the construction process,through the establishment of the mechanism of the actual measurement and analysis of the formation characteristics of the freezing wall,engineering prediction and freezing control,the development trend of the eff

关 键 词：深厚冲积层 冻结孔布置 主冻结孔 辅助冻结孔 防片冻结孔 冻结调控 

分 类 号：TD265.3[矿业工程—矿井建设]