New approach to the design of shaft steelwork

Author: M. Płachno

The key problem in the operation and maintenance of Polish shafts is too short service life of buntons and guides, which has its roots in the adopted design strategy dating back to the 1960s.

Accordingly, the steelwork structure is dimensioned so as to achieve the required endurance factors for the guides and buntons, traditionally made from closed profiles, made by welding of two hollow sections.

Despite the large endurance redundancy, thus manufactured guides and buntons fail to ensure a sufficiently long fatigue life as the maximal admissible loss in the section wall thickness occurs much earlier due to differences in wall thickness.

A definite solution to this problem is the "repair-free steelwork", proposed by the author, i.e. a steelwork that does not require any major repairs throughout the whole projected service life of the shaft: 50-80 years.

This solution was shown to be practicable as long as the new approach to the steelwork design is adopted whereby the proper selection of design parameters helps to reduce the forces to be taken by the steelwork elements, and the fatigue wearing of these elements.

It is emphasised that the new approach might be successfully employed while planning steelwork repairs and modernisation which will soon be necessary in nearly one hundred out of over three hundred shafts currently operated in Poland.