Monitoring of freezing shaft sinking in ultra-deep alluvium of Guotun Coal Mines

The freezing alluvium depth of main shaft of Guotun Mine is 587.5 m, which is the deepest of the world. In order to guarantee the safety of the frozen wall and the shaft wall and achieve rapid construction in the process of shaft sinking, we studied the informatization construction technology. The temperature, shaft load and deformation of completed outer shaft wall were monitored so as to grasp the changing rules of radial load, reinforcement stress, and concrete strain, of the deep shaft. On this basis, the evaluation on safety of the frozen wall and the shaft wall provides a scientific proof for engineering decision in the process of shaft sinking. The findings show that radial load of outer shaft wall is decided by alluvium depth, soil specialty, freezing condition, and shaft wall structure, etc. The results is of practical significance for shaft construction in deep alluvium, and accumulate materials for the deep(freezing) soil mechanics study.