摘要
针对深厚冲积层地区立井井筒冻结中井帮温度偏低的问题,以某风井井筒冻结为例,根据该井筒所处地层以黏性土为主、地下水流速大等特点,进行了外圈孔为主冻结孔的冻结方案设计。采用井帮温度预测值比对方式,采取了调节盐水温度,提前开、停内圈盐水循环,间歇循环等手段,将冲积层段的井帮温度控制在不低于-12℃,取得了较好的效果。在井筒掘进期间进行的井帮位移监测结果表明,当模板高度不高于4 m、单个循环段高掘砌时间不超过32 h时,单侧井帮位移平均值不大于26.5 mm;当单个循环段高掘砌时间从32 h延长至34 h后,约有22%的井帮单侧位移量超过50 mm。
In response to the problem of low shaft wall temperature of the frozen shaft in the deep thick alluvial layer area,taking the freezing of a certain ventilation shaft as an example,a freezing scheme design was carried out based on the characteristics of the shaft being located in the strata dominated by viscous soil and a high flow rate of Neogene groundwater.The design focused on freezing holes in the outer annulus.By comparing the predicted shaft wall temperatures,measures such as adjusting the temperature of brine,initiating and stopping the circulation of brine in the inner annulus,and intermittent circulation were taken to control the shaft wall temperature in the alluvial section to not be below-12℃,and good results were achieved.Shaft wall displacement monitoring conducted during shaft excavation indicated that when the template height was not higher than 4 m and the high excavation time for a single circulation section did not exceed 32 h,the average shaft wall displacement on one side did not exceed 26.5 mm.However,when the high excavation time for a single circulation section was extended from 32 h to 34 h,about 22%of the shaft wall experienced a one-side displacement exceeding 50 mm.
作者
王恒
Wang Heng(Beijing China Coal Mine Engineering Co.,Ltd.;National Engineering Research Center of Deep Shaft Construction)
出处
《黄金》
CAS
2023年第7期83-89,共7页
Gold
基金
山东省技术创新项目(202010606029)
北京中煤矿山工程有限公司自立项目(BMC-ZL-202005)。
关键词
深厚冲积层
人工地层冻结法
多圈孔冻结
井帮温度控制
单侧位移量
井帮收敛
deep thick alluvial layer
artificial stratum freezing
multi-ring hole freezing
shaft wall temperature control
unilateral displacement
shaft wall restraint
