Back-Calculation Method for Estimation of Geomechanical Parameters in Numerical Modeling Based on In-Situ Measurements and Statistical Methods

• Main Author: Adach-Pawelus, K. (Author)
• Format: Article
• Language: English
• Published: MDPI 2022
• Subjects: Back-calculation in geomechanic; back-calculation in geomechanics; Backcalculations; Calculation error; Convergence measurement; Convergence of numerical methods; Copper mines; Excavation; Geomechanics; In-situ measurement; Iterative methods; Mining systems; Model-based OPC; Modeling parameters; non-linear regression; Non-linear regression; numerical modeling; Numerical models; Parameter estimation; Regression analysis; rock mechanics; Rock mechanics; Rocks; Room and pillar mining; room and pillar mining system; Room and pillar mining system
• Online Access: View Fulltext in Publisher

 An important element of numerical modeling for specific mining issues is the selection of model parameters. The incorrect determination of geomechanical parameters can result in significant calculation errors carried throughout the entire problem. This paper presents a method for determining effective geomechanical parameters for technological and residual pillars through the use of numerical modeling, specifically, back-calculation. This is based on the results of numerical simulations, measurement data (e.g., excavation convergence measurements), and statistical methods (a non-linear regression model with “dummy” variables). The result is that appropriate parameters of pillars are set out iteratively so that the displacements of selected points in the numerical model correspond (with some approximation) to the results of mine measurements. The procedure of determining pillar parameters is presented using a case study of one mining field in an underground copper mine, where the deposit is mined using the room and pillar system. Numerical calculations were performed using a Phase2 v. 8.0 program (Rocscience, Toronto, Canada), while statistical calculations used a Statistica computer program. The results of excavation convergence measurements performed in the analyzed mine have been applied. This paper shows that for the presented method, the resulting matching of theoretical values of convergence determined numerically for specified pillar parameters to in-situ results of convergence measurements, is very good (R2 = 0.9896). This work exemplifies a set of the parameters of pillars for an elastic model of rock mass, but this method can also be applied to other models. © 2022 by the author. Licensee MDPI, Basel, Switzerland.