Code Calculations for Local Stability of Shaft Guides

Abstract

Steel structures for a conveyance guiding system are subjected to prolonged, intense corrosion during their operation leading to a considerable loss of material and structure capacity reduction. Shaft guides are made of closed profiles welded from hotrolled channel sections. These profiles are categorized as class 1 cross-sections according to Eurocode 3, which means that they are resistant to local instability upon bending [1]. With an increase in the corrosion loss of the guides, the inertia moment of the crosssection is reduced. The resistance of profiles to local buckling is also reduced. However, calculations for local stability in guides upon bending are not required by the local Polish regulations on the operation of conveyance in shafts [2]. The question is whether this constitutes a shortcoming and risk for safe operation. Calculations according to steel construction standards [1] supported by numerical simulation were used to evaluate shaft steelwork guides resistance to buckling and their sensitivity to corrosion loss. It was shown that the guides of corrosion loss of 52-63%, depending on profile size, are prone to local buckling.

Assessment of the Bending Moment Capacity of Naturally Corroded Box-Section Beams

“…The determined experimental load-carrying capacity was significantly lower than the bending moment resistance calculated on the basis of standard calculations due to the significant influence of shear force in the three-point bending test. The effect of uniform corrosion on channel sections welded to form a box-section beam was investigated by Fiołek et al [ 18 ] and Fiołek and Jakubowski [ 19 ]. By performing laboratory and numerical bending tests, they showed the effect of uniform corrosion on the local buckling resistance of analyzed box beam profiles.…”

“…These profiles are used as guides in the construction of shaft steelwork [ 20 ] and are exposed to atmosphere [ 21 , 22 ], erosion [ 23 ], and mine water [ 24 ] corrosion. Furthermore, high humidity and temperature resulted in high corrosion loss, which is unusual for civil engineering structures [ 18 , 19 , 25 ]. The tested beams were exposed to an underground corrosion environment for over 30 years.…”

Structural Safety Assessment of Shaft Steelwork – A Review

“…the cl allowed by the regulations in Poland [18] is 50% of the nominal wall thickness of the cross-section. Fiołek et al [44] presented studies on the load-carrying capacity of shaft guides as a function of uniform cl with reference to the eurocode 3 (ec3) standards [45]. a series of Fem numerical tests were performed for the selected profile, which exhibited high compliance with the standard calculations.…”

“…11) [49]. the resistance assessment considered the sensitivity to local buckling [44,46,47] and the uncertainty of the steel strength properties [52]. The load effects and resistance probability distributions enabled a probabilistic shaft steelwork reliability analysis.…”

Evaluation of Stiffness and Dynamic Properties of a Mine Shaft Steelwork Structure through In Situ Tests and Numerical Simulations

“…They accounted for the impact of structural weakness resulting from corrosion in steelwork elements. Experimental research on the load-carrying capacity of shaft guides was conducted by Fiołek and Jakubowski [9] and Fiołek et al [10]. They showed that high corrosion loss reduces the resistance to local buckling of hotrolled profiles.…”