Research and application of high strength steel fiber concrete compound shaft lining with inner steel plate in deep alluvium shaft repair

Aiming at the complicated engineering conditions of auxiliary shaft repair in Banji Coal Mine, the inner sleeve of composite shaft lining structure of high strength steel fiber concrete with inner steel plate is proposed. Firstly, the mechanical properties of new type of shaft lining are studied by model test,the results show that the ultimate strain of high strength steel fiber concrete in shaft lining structure can reach -3 710με to -3 750με,and the ductility of shaft lining structure is obviously improved. Due to the role of inner plate restraint,the steel fiber concrete at the inner edge of shaft is compressed in three directions,and the steel fiber concrete compressive strength increased 1． 822 to 1.974 times,which significantly improved the bearing capacity of composite shaft lining. Then,the first application of inner steel plate of steel fiber high strength concrete composite shaft lining in Banji Coal Mine auxiliary shaft repair- men,and the site measurement results show that the two monitoring level of strain in steel fiber concrete is respectively -290με and -359με,which is far less than the ultimate compressive strain. It shows that deformation of new type of shaft lining concrete is small,and the structure of shaft lining is safe and reliable.