Monitoring and Analysis on Shaft Freezing Temperature Field of Cretaceous Water-rich Bedrock in Xinzhuang Coal Mine

In order to accurately grasp the development law of shaft freezing temperature field in Cretaceous strata water-rich bedrock, through shaft freezing monitoring in Xinzhuang Coal Mine,it obtained temperature decrease data of the Cretaceous strata in this region under the certain condition.Then it studied the distribution law of the initial strata temperature field in this region,as well as the temperature variation law of brine loop in the freezing pipes.Moreover,it carried out comparative analysis for the development characteristics of freezing temperature field while different lithology changed with time,thus obtained Cretaceous strata cooling rate,it was that coarse conglomerate> coarse-grained sandstone> medium-grained sandstone> argillaceous siltstone> sandy mudstone.By the measured data, it calculated and obtained that the maximum expansion rate of freezing wall in Cretaceous Luohe group strata was 0.082 m/d, and the minimum expansion rate of freezing wall in the maximum depth shale was 0.033 m/d,the expansion rate of freezing wall was fast for the freezing time from 60 to 150 days,which provided a reference to estimate the positive freezing time.