ISO 19426-5:2018 pdf free

ISO 19426-5:2018 pdf free.Structures for mine shafts – Shaft system structures
Mining operations and geological conditions lead to strains of differing magnitude in the rock immediately surrounding the shaft. As soon as mining operations commence, the natural strain in the rock changes due to extraction of rock. These changes in rock strain can have a significant influence on the functional performance of mine underground structures, and in particular on mine shaft structures. Four shaft zones are defined, based on the predicted strain changes not exceeding the limits given in Table A.1.
Shafts shall be classified into condition categories as shown in Tables B.1 and B.2 because of the correlation between structural loading and maintenance. These tables may be applied in different ways by the designer. For example, if the designer anticipates poor maintenance of a shaft, the design will consider high loads. On the other hand, the operator of a shaft designed to accommodate only moderate forces shall make sure that the maintenance programme keeps the system performance within the appropriate range.
The individual or group that classifies a new or existing shaft shall be in a position to evaluate all the ramifications of the decision, including capital cost versus maintenance cost trade-offs. Specifying a system as category C for design and as category B during operation would be appropriate. Such a degradation by one category will ensure that the design will always be conservative relative to the expected performance of the structural system.
Shaft conditions can vary considerably within one shaft, and consequently different shaft classifications may be used for different portions of any shaft.
Table B.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. Table B.1 also gives the various factors used in this part of ISO 19426 for defining loads and fatigue cycles for vertical shafts.
Table B.2 gives key values from which the shaft condition classification of existing decline shafts may be determined, and from which the shaft condition classification of new decline shafts may be predicted.Table B.2 also gives the various factors used in this part of ISO 19426 for defining loads and fatigue cycles for decline shafts. ISO 19426-5 pdf download.