## 2 Literature Review
### Numerical Analysis  
With the large technological growth and capabilities of computers, the shift to utilising technological innovations to conduct analyses has become more prevalent. It is only natural that numerical modelling has become the next progressive step for scholars to model the reactionary behaviour of rockbursts.  
Numerical modelling was first introduced in the 1960s [18], however, it was not till the 1970s that this was applied to the analysis of rockbursts. The first notable use of numerical modelling was conducted by [PERSON] (1972) [19]. The results from the simulation of the elastic pulse propagation problem of the Split-Hopkinson Pressure bar agreed with the derived strain and strain-time curves. This was the first time numerical modelling was recognised as a potential new analytical model. [PERSON] (1972), had used the FEM to study pillar bursts. From his analysis, he concluded that areas of high stress concentrations are strong predicators of rockburst locations, now a commonly supported theory [7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22]. [PERSON] and [PERSON] (2002) [18; 23] classified numerical approaches as continuum, discontinuum and hybrid methods, a summary of their findings can be seen below in Table 2.  
The application of numerical analysis has spanned across many areas of rock mechanics and has proven to yield reliable results, particularly concerning tunnelling and deep mining excavation [24; 25; 26]. Whilst numerical modelling generally shows strong positive results that agree with analytical equations, it is not without its flaws. FDM code STEALTH and the BEM Code, MINAP was used to evaluate rock failure and dynamic instabilities. In the study, it was remarked that the stored energy results obtained from MINAP, which used the elastic constitutive model, was smaller than STEALTH which employed a non-constitutive model. [PERSON] et al. (2021) highlights the importance of careful selection of various numerical modelling software suggesting that there needs to be compatibility between the fundamental principles of the software, the rockburst mechanism and the specific engineering situation.  
[PERSON] et al. (2021) [27], highlights the capabilities of numerical modelling to be an accurate form of analysis to examine various loading and encourages the use of numerical modelling as technological capabilities and skills grow. However, concern for the ability to accurately model boundary conditions has been the primary issue and limitation of numerical modelling [25; 26; 27; 28].  
Numerical modelling has grown to become a primary form of analysis. It has seen a growth in usage amongst researchers as a complimentary method of supporting field testing. [PERSON] and [PERSON] (2001) [12], utilised both blasting and numerical modelling to model wave propagation due to seismic activity. They concluded that the numerical waveform corresponded closely to the analytical result which was supported by their collaborative blast model indicating realistic tunnel motions that were to be replicated through their numerical model. Similarly, in the [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON] (2018) study, they investigated the development of a numerical model to test the structural response of cable bolts subject to static and dynamic loading, with a particular focus on shearing effects. These results were compared with [PERSON] et al. (2017) [29] double shear testing which agreed with the results obtained from the ABAQUS model. As further research continues to investigate combined support systems subject to dynamic loading through the use of numerical analysis, testing can be replicated in a safe, repeatable and cost-friendly manner [6; 30]. ([PERSON], [PERSON], & [PERSON], 2021) [30; 31; 32; 33; 34; 35; 36; 37; 38] also presented a significant contribution to the latest research in the current field.