摘要
针对淮南矿区6个改扩建冻结井筒在水文观测孔刚施工结束,还未送冷,水文孔就出现异常冒水现象,采用模型试验、数值模拟和工程实践相结合的方法,对水文孔异常冒水原因与冻结壁交圈判断条件进行了分析研究。结果表明:由于6个井筒均采用"上冻下注"法凿井,下部基岩段注浆与上部冲积层段冻结同时施工,地面预注浆压力很大,造成基岩裂隙水压升高,通过弱透水层发生越流作用,对松散含水层进行补给;随着注浆量的不断增加,该松散含水层水位不断上升,直至从水文孔冒出,从而找出了水文孔异常冒水的原因。并通过进一步研究,提出了该种情况下的冻结壁交圈判断标准,并得到工程实践验证,确保了冻结井筒安全施工。
In view of the abnormal phenomenon that water emitting from many hydrological observation holes of 6 reconstruction shafts by freeze sinking method after the hydrological observation holes being drilled and before the cold being sent to the reported strata in Huainan Mining Area,a series of model test,numerical simulation and engineering practice were adopted to research the causes of abnormal phenomenon of water emitting from hydrological observation hole and the judgment conditions of frozen wall connection.The result shows：because these 6 shafts were all constructed by special shaft sinking method of＂freezing upper strata and grouting lower strata＂,the lower bedrock section was grouted and the upper alluvium section was frozen at the same time;the pressure of pre-grouting at surface ground was very high,the grouting caused the pressure of bedrock fissure water to rise,the water produced the leakage and recharged the above loose aquifer through the weak permeable layer between these two aquifers;with the increasing of grouting volume,the water level of the loose aquifer constantly increased,until it emitted from the hydrological hole,so the causes of abnormal water emit-ting from hydrological hole were found.And through further research,the judgment standard of frozen wall connection under these conditions was put forward,and has been verified by engineering practices,it could ensure the safe construction of shafts by freeze sinking method.
作者
唐永志
汤江明
姚直书
TANG Yongzhi;TANG Jiangming;YAO Zhishu(Huainan Mining Group Co. ,Ltd. ,Huainan 232001,China;School of Civil Engineering and Architecture ,Anhui University of Science and Technology ,Huainan 232001,China)
出处
《建井技术》
2018年第1期1-5,共5页
Mine Construction Technology
基金
国家科技重大专项(2016ZX05068)
国家自然科学基金资助项目(51674006)
安徽省高校学科(专业)拔尖人才学术基金资助项目(gxbjZD09)
关键词
改扩建
冻结法
水文孔
异常冒水
冻结壁交圈
reconstruction
freeze sinking method
hydrological hole
abnormal running water emitting
frozen wall connection
