AS NZS 3785.6:2015 pdf free

AS NZS 3785.6:2015 pdf free.Underground mining一Shaft equipment
Historically, simplified static design procedures have been used and have proved to be successful in many applications. The practice applies a horizontal acceleration of typically 1 m/s- acting through the conveyance centre of gravity (or a force equivalent to approximately 10% of the conveyance weight). This is reacted by forces acting at the points of contact between the conveyance and the guide. The most obvious deficiency of this method is that the design forces so derived are independent of the conveyance velocity.
Whilst this approach may be suitable under some circumstances, it is not recommended unless used in conjunction with rigorous evaluation of the proposed design against existing successful designs. Factors for such evaluation should include the following:
(a) Hoisting speed.
(b) Conveyance mass.
(c) Bunton spacing.
(d) Guide-to-bunton stiffness ratio.
(e) Conveyance slipper plate locations.
(f) Guide misalignment tolerances.
(g) Number and location of guides.
The method specified in this Standard is based on dynamic analysis methods. The method computes the forces arising from so called slamming’events whereby the conveyance travelling along the guides‘slams’ into the guides with an initial velocity normal to the guide. This initial velocity is induced by the misalignment of the guides. In this method,forces are affected by the magnitude of guide misalignment, the conveyance mass, the conveyance vertical velocity and the stiffness of the guidance structure.
Shafts shall be classified into condition categories as indicated in Table 1. Table 1 provides the correlation between structural loading and maintenance requirements.Shaft conditions can vary considerably within one shaft, and consequently different shaft classifications may be used for different portions of any shaft.Table 1 gives key values from which the shaft condition classification of existing vertical shafts may be determined, and from which the shaft condition classification of new vertical shafts may be predicted. It also gives the various factors used in this Standard for defining loads and fatigue cycles for vertical shafts.AS NZS 3785.6 pdf free download.