冻结井外层井壁混凝土水化热对冻结壁的影响规律研究  

Study on the influence law of hydration heat of concrete in outer wall of frozen well on frozen wall

作　　者：马昊辰 荣传新[1] 龙伟 黄诗清 MA Haochen;RONG Chuanxin;LONG Wei;HUANG Shiqing(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001

出　　处：《煤矿安全》2022年第6期218-226,共9页Safety in Coal Mines

基　　金：国家自然科学基金资助项目(51374010,51878005)。

摘　　要：为了得到冻结井外层井壁混凝土水化热对冻结壁的影响规律,采用现场实测与数值计算方法对淮北青东煤矿东风井外层井壁浇筑混凝土期间冻结壁的冻融情况进行了分析。结果表明:井壁混凝土浇筑后10 d内为冻结壁急剧升温阶段,冻结壁达到最大融化深度;水化热使得黏土层位冻结壁井帮升温至20℃以上,升温幅度达25℃以上,黏土层位最大融化深度达到334~358 mm,黏土层位最大融化深度是细砂层位的4.0~4.5倍;在保持冻结孔正常的供冷条件下,井壁混凝土浇筑26 d后,融化的冻结壁完成回冻,因此井壁混凝土有充足的正温养护时间,不会影响其早期强度;井壁混凝土入模温度与冻结壁融化深度呈指数函数变化的非线性关系;冻结壁与井壁之间的聚苯乙烯泡沫塑料板可有效的减小深部地层中井壁混凝土水化热对冻结壁的影响,保证冻结壁不会因水化热的影响而融化深度过大,从而有效的保证了施工过程中冻结壁强度与稳定性。In order to obtain the influence law of hydration heat of concrete on the frozen wall,the freeze-thaw condition of the frozen wall during concrete pouring in the outer wall of Dongfeng well in Huaibei Qingdong Coal Mine was analyzed by field measurement and numerical calculation,and the results show that the freezing wall heated up rapidly within 10 days after concrete pouring,and the freezing wall reached the maximum thawing depth;the heat of hydration heats up the well wall of the frozen wall of the clay layer to more than 20 ℃,and the heating range is more than 25 ℃.The maximum thawing depth of the clay layer is 334-358 mm,and the maximum thawing depth of the clay layer is 4.0-4.5 times that of the fine sand layer.Under the normal cooling condition of the frozen hole,the thawing frozen wall was refrozen after pouring concrete for 26 days,so the concrete had sufficient positive temperature curing time,which will not affect its early strength.There is a nonlinear exponential function between the temperature of concrete in the shaft wall and the thawing depth of the frozen wall.The polystyrene foam board between the frozen wall and the shaft wall can effectively reduce the influence of the hydration heat of the shaft wall concrete on the frozen wall in the deep stratum,and ensure that the freezing wall will not melt too deep due to the influence of hydration heat,thus effectively ensuring the strength and stability of the frozen wall in the construction process.

关 键 词：冻结法凿井 冻结壁 混凝土水化热 融化深度 数值计算 

分 类 号：TD265[矿业工程—矿井建设]