Pre-mining stress model for subsurface excavations in southern Africa
Pre-mining stress model for subsurface excavations in southern Africa
复制标题
南部非洲地下挖掘的预开采应力模型
DOI：
10.1002/2013tc003402
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
M. Handley
中科院分区：
文献类型：
--
作者：
M. Handley
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Rock conditions and the distribution of payable ore underground control the mining strategy adopted and the resulting mine layout. Mine stability then depends on the relationship between the strength of the rock mass and the total field stresses, which result from the mine layout. Since the field stresses are always the sum of the primitive stresses and the mining-induced stresses, both must be known to a reasonable degree of accuracy, since the risk of instability may need to be estimated both during mining and after mining has ceased. Either the primitive stresses must be obtained from in situ stress tensor measurements or from a good pre-mining stress model (initially limited to the depth of mining of 4 km), while the mining-induced stresses come from numerical models of the mine and the rock mass structure. Rock stress data from in situ measurements is scarce because it is both difficult and expensive to obtain. Workable stress measurement technology became available to mining only during the 1960s (Leeman, 1965, 1968; Pallister, 1969). At the same time, means to calculate stress changes induced by mining were being introduced (Salamon, 1965; Salamon et al. 1965; Ortlepp and Nicoll, 1965). There are no good premining stress models because of the difficulty and cost of obtaining stress data. This paper demonstrates that the pre-mining stress models currently used in rock mechanics are inadequate, and addresses the problem of deducing a generic primitive stress model for mining from the Southern African Stress Database. The Southern African Stress Database is a good source of primitive stress data, compiled from stress measurements made all over southern Africa from May 1966 to October 1997 (Stacey and Wesseloo, 1998a). The compilers state that the database should be used for this purpose by the mining industry, but to date none of the data has appeared in the literature. There is another stress database known as the World Stress Map, which is built up from earthquake data worldwide (Heidbach et al., 2009). This database contains only eight records for South Africa, and none is suitable for building a primitive stress model for mining purposes. Pre-mining stress model for subsurface excavations in southern Africa