scholarly journals Stiffness Determination of Backfill-Rock Interface to Numerically Investigate Backfill Stress Distributions in Mine Stopes

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Guangsheng Liu ◽  
Xiaocong Yang ◽  
Lijie Guo
Keyword(s):  
Numerical Modeling ◽  
Underground Mining ◽  
Earth Pressure ◽  
Shear Stiffness ◽  
Variable Stiffness ◽  
Empirical Method ◽  
Stress Distributions ◽  
Interface Elements ◽  
Essential Components ◽  
Backfilled Stopes

Numerical modeling is an effective and efficient method to investigate the stress distributions of backfill in stopes, which should be well understood in underground mining. Interface elements between backfill and rock in simulated stopes had been proved to be essential components, for which the stiffness parameters need to be assessed and assigned. However, few reports have revealed the effects of interface stiffness on backfill stress distributions, and there is not yet a clear solution to determine the interface stiffness to simulate stresses in backfilled stopes, except an empirical method for simply applying a high value suggested in FLAC manual. In this study, a new solution is first proposed to determine the normal stiffness and shear stiffness of interface elements, respectively, in numerical modeling of backfill stresses. The applicability of the solution has been verified by investigating backfill stress distributions in mine stopes of two widely used mining methods with variable stiffness values. The results show that the newly proposed method leads to totally the same backfill stress distributions with models applying the interface stiffness by the method in FLAC manual based on a “rule-of-thumb” but will save at least 20%–30% calculation time to improve modeling efficiency under the same simulation conditions and will carry much clear physical meanings corresponding to the interaction between backfill and rock walls in mine stopes. In addition, the vertical and horizontal stresses show good agreements with the analytical stresses predicted by the Marston equation under the at-rest state, which validates the reliability of the proposed solution for interface stiffness. Moreover, the plotting methods of stress distributions and the coefficient of lateral earth pressure of backfill in simulated stopes with proposed interface stiffness were discussed to further clarify the reasonable methods to investigate the backfill stresses in mine stopes, especially after considering the effects of the convergence from rock walls, which is a very significant and common phenomenon in practical mining engineering.

scholarly journals 3D Numerical Modeling of Large Piled-Raft Foundation on Clayey Soils for Different Loadings and Pile-Raft Configurations

2020 ◽  
Vol 42 (1) ◽  
pp. 1-17
Author(s):  
Shivanand Mali ◽  
Baleshwar Singh
Keyword(s):  
Numerical Modeling ◽  
Soil Profile ◽  
Bending Moment ◽  
Load Sharing ◽  
3D Numerical Modeling ◽  
Interface Elements ◽  
Pile Spacing ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation

AbstractIn a piled-raft foundation, the interaction between structural elements and soil continuum can be simulated very precisely by numerical modeling. In the present study, 3D finite element model has been used to examine the settlement, load-sharing, bending moment, and shear force behavior of piled-raft foundation on different soil profiles for different load configurations and pile-raft configurations (PRCs). The model incorporates the pile-to-soil and raft-to-soil interactions by means of interface elements. The effect of parameters such as pile spacing and raft thickness are also studied. For any soil profile, larger pile spacing is observed to be more efficient in reducing the average settlement and enhancing the load-sharing coefficient. The smaller pile spacing is observed to be efficient in reducing the differential settlement. For any soil profile, the behavior of piled-raft foundation is significantly affected by the PRCs and load configurations. Furthermore, the raft thickness has significant effect on settlement, bending moment, and shears force. Thus, the results of the present study can be used as guidelines for analyzing and designing large piled-raft foundation.

scholarly journals NUMERICAL MODELLING FOR UNDERGROUND MINING RELATED GEOTECHNICAL ISSUES

2013 ◽  
Vol 35 (3) ◽  
pp. 13-24
Author(s):  
L. Florkowska
Keyword(s):  
Numerical Modeling ◽  
Numerical Modelling ◽  
Continuous Monitoring ◽  
Underground Mining ◽  
Mining Areas ◽  
Geotechnical Problems ◽  
Mathematical And Numerical Modeling

Abstract Issues presented in this work relate to geotechnical problems that are specific to the mining areas. The paper discusses the methodology of mathematical and numerical modeling of these problems. Examples contained in the paper include: predicting the influence of mining exploitation on a detached building and evaluating the effectiveness of the building protection with the trench. Possible applications of numerical modeling as a tool to aid the continuous monitoring of the building state during the exploitation have also been discussed

Prediction of Mechanical Properties of Ceramic Biocomposite on the Basis of Numerical Modeling

2017 ◽  
Vol 743 ◽  
pp. 172-175 ◽  
Author(s):  
Valentina A. Mikushina ◽  
Igor Yu. Smolin ◽  
Yury N. Sidorenko
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Numerical Modeling ◽  
Stress Distribution ◽  
Damage Accumulation ◽  
Strength Criterion ◽  
Stress Distributions ◽  
Mesoscopic Level ◽  
Distribution Laws ◽  
Prediction Of Mechanical Properties

The numerical simulation of biocomposites consisting of zirconia-based ceramics and cortical bone was performed with the use of a multilevel approach. The mechanical properties of the ceramic biocomposite were determined. The evolution of mesoscopic stress distributions in the biocomposite components during the process of its deformation was investigated, taking into account damage accumulation up to the fulfillment of the macro strength criterion. It is shown that damage accumulation has an impact on the stress distribution laws at the mesoscopic level, which is manifested through the appearance of a threshold for the stress distribution, as well as through a significant decrease in the distribution amplitude.

MODELING THE STRESS STATE OF THE BACKFILLING MASS WITH DIFFERENT PHYSICAL AND MECHANICAL PROPERTIES

2021 ◽  
pp. 7-18
Author(s):  
Mykhailo Petlovanyi ◽  
◽  
Kateryna Sai ◽  
Keyword(s):  
Mechanical Properties ◽  
Numerical Modeling ◽  
Stress State ◽  
Physical And Mechanical Properties ◽  
Practical Significance ◽  
Mining Operations ◽  
Mining Depth ◽  
Compressive Stresses ◽  
A Value ◽  
Backfilled Stopes

Purpose. Analytical researches of the stress state of the backfilling stopes with different physical and mechanical properties using numerical modeling to determine possible zones of stability losses and predict their failure. Methods. Numerical modeling of the formation of stresses around a high stopes was carried out for the conditions of mining iron ore reserves in the depth intervals of 740-1040 m of the Pivdenno-Bilozerske deposit, where mining operations are actively carried out using the finite element method in the SolidWorks 2016 software package with reliable substantiation of the parameters of the developed geomechanical model. Results. Numerical simulation of the stress state of the backfilling mass are carried out at variable values of the modulus of its elasticity and the mining depth. It was found that with the existing actual physical and mechanical properties of the backfilling mass during the development of the Pivdenno-Bilozerske deposit, the danger of its failure is predicted at depths of more than 890 m. In the center of the filling array, the stress values change linearly, and at the junction of the roof with the side of the backfilled stopes – polynomial. It was found that an increase in the modulus of elasticity of the backfilling mass allows to reduce the compressive stresses only at the junction of the roof with the side of the backfilled stopes to a value of 800 MPa. Scientific novelty. With an increase in the depth of development, despite an increase in the elastic modulus of the fill, the values of stresses increase, which eliminates the need to increase it with a decrease in the mining depth it was found. Practical significance. The results obtained make it possible to correct the technology of formation of a backfilling mass in the primary stopes, taking into account the formation of stresses on its contour and, with an increase in the mining depth, to form a backfilling mass with viscoplastic properties.

Numerical Modeling of Lateral Earth Pressure Acting on Box Culvert under the Ground Deformation

2014 ◽  
Vol 577 ◽  
pp. 1166-1169
Author(s):  
Jun Wu Xia ◽  
Guo Tao Dou ◽  
Di Wang ◽  
Zhen Hua Lu
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Ground Deformation ◽  
Earth Pressure ◽  
Mining Subsidence ◽  
Damage Potential ◽  
Finite Element Software ◽  
Lateral Earth Pressure ◽  
Box Culvert ◽  
The Way

Box culvert affected by mining subsidence is exposed to damage potential in relation to the lateral earth pressure. This study intends to specify and compare different ground deformation by the mining subsidence effect in box culvert. For this purpose, a finite-element software (ANSYS) is used to generate models incorporating the soil and a box culvert. The results shows that the lateral earth pressure of box culvert was related to the way of ground deformation, In addition, the kind of soil also affected the distribution and value of the lateral earth pressure.

Viscoplastic Model with Zero-Thickness Interface Elements for Lateral Earth Pressure on Wall Due to Line Load

2013 ◽  
Vol 43 (3) ◽  
pp. 203-217
Author(s):  
Rafi’ Mahmoud Sulaiman Al-Ne’aimi
Keyword(s):  
Earth Pressure ◽  
Interface Elements ◽  
Line Load ◽  
Viscoplastic Model ◽  
Lateral Earth Pressure

scholarly journals Numerical modeling of open pit (OP) to underground (UG) transition in coal mining

2016 ◽  
Vol 38 (3) ◽  
pp. 35-48 ◽  
Author(s):  
Phu Minh Vuong Nguyen ◽  
Zbigniew Niedbalski
Keyword(s):  
Numerical Modeling ◽  
Coal Mining ◽  
Surface Deformation ◽  
Underground Mining ◽  
Primary Objective ◽  
Open Pit ◽  
Open Pit Mining ◽  
Original Experiment ◽  
Surface Stability ◽  
The Impact

Abstract The primary objective of the present paper is an attempt at evaluating the influence of sub-level caving operations on the slope stability of a still-functioning open pit coal mine in Vietnam. Initially, various methods of predicting the impact of underground mining on surface stability are discussed. Those theoretical considerations were later utilized in the process of constructing a Flac-2D-software-based numerical model for calculating the influence of underground operation on the deformation and possible loss of stability of an open pit slope. The numerical analysis proved that the values of open pit slope displacements were affected mainly by underground exploitation depth, direction of operation (i.e., from one slope to the other) and the distance from the slope plane. Real geomechanical strata parameters from the Vietnamese coal basin of Cam Pha were used in the modeling process. The paper is, therefore, a critical review of the hitherto proposed methods of predicting the impact of underground operation (UG) on open pit mining (OP), illustrated with selected examples of case studies on OP-UG interaction, followed by an original experiment based on numerical modeling method. This is first such study for the genuine conditions of the coal mining in Vietnam. The obtained results, however, should not be generalized due to a highly specific character of the analyzed phenomenon of mining-induced surface deformation. The practical implications of the study may occur extremely useful in the case of an UG-OP transition. Such a transition is often necessary for both technical and economical reasons, as in some coal basins open pit operations at greater depths occur unfeasible, which calls for a proper selection of parameters for a planned underground operation.

Numerical modeling of three-dimensional active earth pressure acting on rigid walls

2013 ◽  
Vol 51 ◽  
pp. 83-90 ◽  
Author(s):  
Florian tom Wörden ◽  
Martin Achmus
Keyword(s):  
Numerical Modeling ◽  
Three Dimensional ◽  
Earth Pressure ◽  
Active Earth Pressure ◽  
Rigid Walls

Numerical Modeling of Rock-Bit Interaction in Laminated Formations

1994 ◽  
Vol 116 (1) ◽  
pp. 38-48 ◽  
Author(s):  
M. G. Karfakis ◽  
H.-J. Ouyang
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Progressive Failure ◽  
Variable Stiffness ◽  
Quantitative Information ◽  
Quantitative Agreement ◽  
Finite Element Program ◽  
Penetration Process ◽  
Element Program ◽  
Rock Bit

Numerical modeling of the rock-bit interaction process in laminated formation has been performed using a finite element approach. A finite element program was developed with the assumption of plane strain. Anisotropic elements, dynamic, loading, progressive failure, and variable stiffness were used to represent the actual penetration process. The Hoek and Brown failure criterion was used in the failure analysis. An interation method, using an incremental approach, has been applied for the continuous tooth penetration process where displacements, axial loads, strength and stiffness of elements are modified after each iteration. The program provides quantitative information on stress, displacement, and rock failure for each iteration. Furthermore, deviation due to laminated formation can be inferred and the effects of changing bit geometry can be assessed. The model also shows good quantitative agreement with laboratory wedge indentation tests.

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