Model experimental study on the safety characteristics of surrounding rock supports in deep wells

Abstract

To study the use of a shaft support for the auxiliary shaft of the Xi’anshan Iron Mine, in high-stress strata at a depth between 900 and 1000 m, a new type of mold was developed using the physical similarity model test method, based on the similarity theory, and an experimental model of the shaft lining and surrounding rock was poured. Two sets of large-scale destructive tests were conducted on the shaft lining and surrounding rock. The deformation and failure laws of the shaft lining and surrounding rock under high ground stress and their ultimate horizontal bearing capacity characteristics were studied, and the safety support characteristics of the shaft lining under the interaction of the shaft lining and surrounding rock were obtained. An experimental study demonstrated that the axial pressure on the shaft wall directly affected its ultimate horizontal bearing capacity of the shaft wall. In designing the shaft wall, the influence of the axial pressure on the stress state of the concrete should be considered, and the vertical pressure should be modified to optimize the utilization of the three-dimensional compressive strength of the concrete. The reliability of the 400-mm C30 concrete shaft wall at a depth of 1000 m in the actual project was verified, and the ultimate horizontal bearing capacity of the shaft wall was obtained for a depth of 1000 m.

Keywords

physical similarity model / high ground stress / shaft support / ultimate bearing capacity / law of destruction

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University of Science and Technology Beijing