The reasonable size range of the exposed face of the stope was calculated by performing theoretical analysis on the ultimate span. The Mathews stability map method and Barton limit span theory were used. In this study, we used a large-scale tungsten mine in Jiangxi Province as the engineering background and performed on-site engineering geological surveys and indoor ore rock mechanics tests in the middle section of mine 417 to obtain multiple engineering quality indicators for the mines and surrounding rocks. This is where the economic challenge of excavation design will be critical to success.Mathews stability graphic method, based on the rock classification system, measures the stability of the ore roof area of a relatively simple calculation method and provides a theoretical basis for mine rational design stope structure size parameters. Working within the constraints that the low strength of the intact rock places on mine design, soft rock miners use an approach that will interest traditional hard rock miners as they target resources at greater depths. Two- and three-dimensional numerical assessments of large deposits can be conducted rapidly using displacement discontinuity methods in the Map3D boundary element code, while more detailed assessments use the FLAC and FLAC3D finite difference codes. SRK has experience in classifying soft and weak rocks to set the parameters for these tools. Empirical and numerical design tools developed for excavation design are based mainly on experience gained in coal and potash mining operations and research in nuclear waste disposal. However, the datasets used to develop the design tools are smaller and, combined with sedimentary rocks’ variability, must be used with care. In concept, the techniques applied to the design of excavations in soft and weak rock are very similar to hard rock design techniques. It is essential to consider the stability of the larger rock mass located at a distance from the mine excavations, particularly where even minor inflows of water – easily managed in hard rock mining – can result in the loss of a mine. The mining method chosen must accommodate the large displacements of the rock around an excavation when yielding pillars are used. Pillars can be allowed to yield to maintain the safety and integrity of excavations long enough to allow the mineral to be extracted. The time dependent behaviour of many soft rocks can be taken advantage of by allowing creep deformation of the rock with minimal loss of strength. Instead, such excavations must be modified to allow the controlled yielding and displacement available with alternative mining methods. The normal stresses of mining can exceed the uniaxial compressive strength of soft rock even at shallow depths, and excavations based on criteria accepted in hard rock mining inevitably fail. While a good starting point, these experiences often do not account for the unusual physical properties of soft rock that lead to adopting a conservative design.
![uniaxial compressive strength of rock in flac3d uniaxial compressive strength of rock in flac3d](http://docs.itascacg.com/flac3d700/_images/uniaxialcomptest-p1.png)
![uniaxial compressive strength of rock in flac3d uniaxial compressive strength of rock in flac3d](http://docs.itascacg.com/flac3d700/_images/pulltest-cable1.png)
Most of the tools and techniques available to the mining and rock mechanics engineer are based on the experiences of practitioners in hard rock mining.
#Uniaxial compressive strength of rock in flac3d full#
These deposits are often tabular and, are subjected to the full weight of the overburden, are of relatively low strength, which makes underground high extraction problematic.
![uniaxial compressive strength of rock in flac3d uniaxial compressive strength of rock in flac3d](https://media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10064-019-01690-0/MediaObjects/10064_2019_1690_Fig2_HTML.png)
![uniaxial compressive strength of rock in flac3d uniaxial compressive strength of rock in flac3d](http://docs.itascacg.com/flac3d700/_images/p3d-tuto-rocktest-fj-ucs.png)
The economic success of industrial mineral projects,such as potash, often depends on recovering high tonnages at low cost.