Estimation of horizontal regional stresses at an open-pit limestone mine by back analysis

2002 ◽  
Vol 6 (3) ◽  
pp. 175-180
Author(s):  
Seong-Seung Kang ◽  
Jun-Mo Kim ◽  
Katsuhiko Kaneko ◽  
Yuzo Obara
Keyword(s):  
Back Analysis ◽  
Open Pit ◽  
Regional Stresses

Back analysis and radar interferometry monitoring in a large open pit slope

2014 ◽  
pp. 925-930
Author(s):  
C González-Nicieza ◽  
M Álvarez-Fernández ◽  
O Mora ◽  
E Amor-Herrera
Keyword(s):  
Back Analysis ◽  
Radar Interferometry ◽  
Open Pit

scholarly journals Parameter inversion and location determination of evolutionary weak layer for open-pit mine slope

2020 ◽  
Vol 7 (4) ◽  
pp. 714-724
Author(s):  
Zhao Hongze ◽  
Wang Dongyu ◽  
Ma Ming ◽  
Zheng Kaihui
Keyword(s):  
Shear Failure ◽  
Back Analysis ◽  
Friction Angle ◽  
Dynamic Mechanical Properties ◽  
Simulation Software ◽  
Open Pit Mine ◽  
Monitoring Data ◽  
Open Pit ◽  
Open Pit Mines ◽  
Parameter Inversion

AbstractIn light of the complex and dynamic mechanical properties of evolving weak strata in open-pit mines, and the consequent difficulty of determining their mechanical parameters, this study uses the ultimate balance theory, along with the back analysis method combined with monitoring data on field displacement, to carry out parameter inversion using the FLAC3D numerical simulation software. The edge slope of a working pit of the Weijiamao open-pit mine was used as research object to this end. As the results obtained by the constitutive model were consistent with the field monitoring data, the evolving weak strata in the slope and the position of the landslide in the mine could be obtained. The landslide was directed northeast. The mechanism of the edge slope of the working pit was identified as unloading shear failure, and the feasibility of the method of parameter inversion was verified. The internal friction angle ϕ and cohesion C of evolving weak strata in the slope of the open-pit mine were also obtained, where this compensated for the deficiency of laboratory tests and enabled the transformation from qualitative to quantitative analysis. This can provide a reliable basis for the safe operation of open-pit mines.

Application of a rock buttress in the design of slopes of a strip coal mine adjacent to a highway

1993 ◽  
Vol 30 (3) ◽  
pp. 391-408 ◽  
Author(s):  
R. Ulusay ◽  
M.F. Yolerì ◽  
V. Doyuran
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Back Analysis ◽  
Bedding Plane ◽  
Open Pit ◽  
State Highway ◽  
Planar Surfaces ◽  
Thermal Coal ◽  
Basal Sliding ◽  
The Stability

Eskihisar open pit mine, located at Yatagan, southwest Turkey, produces thermal coal for a power generating plant. As mining of strips advanced southwards, instability appeared to be highly critical due to the movements in the southeast wall slopes adjacent to the state highway running parallel to the pit boundary. This situation called for an immediate response to initiate a detailed geotechnical investigation program and to redesign the pit slopes. This paper outlines the most probable mode and mechanism of instability along the southeast wall, as well as field and laboratory studies, results of back analysis, discussion of the data requirements, and results of slope stability analyses performed to ensure adequate overall stability. The studies revealed that the most critical failures may occur along two or three planar surfaces, by combination of fault, bedding plane, and localized strata steepening adjacent to the fault, in multiplanar failure mode controlled by faulted blocks. The stability is sensitive to changes in length of the lower part of the basal sliding surface, as well as to the configuration and shear strength of black and highly plastic underclay. The effects of a buttress of intact rock and slope flattening on the stability are compared and discussed. Key words : back analysis, multiplanar failure, shear strength, slope stability, toe buttressing.

scholarly journals Sensitivity Analysis and 3D-displacement Inversion of Rock Parameters for High Steep Slope in Open-pit Mining

2016 ◽  
Vol 10 (1) ◽  
pp. 448-460 ◽  
Author(s):  
C.B. Zhou ◽  
R. He ◽  
N. Jiang ◽  
S.W. Lu
Keyword(s):  
Neural Network ◽  
Sensitivity Analysis ◽  
Back Propagation ◽  
Back Analysis ◽  
Steep Slope ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mechanical Parameters ◽  
The Real ◽  
Geological Conditions

Due to the complexity of multiple rocks and multiple parameters circumstance, various parameters are often reduced to only one parameter empirically to generalize geological conditions, ignoring the really influential parameters. A developed method was presented as a complement to 3D displacement inversion to obtain the relative important parameters under complex conditions with limited computational work. Furthermore, this method was applied to a high steep slope in open-pit mining to investigate field applicability of the developed system. Back analysis was conducted in the reality of the east open-pit working area of Daye Iron Mine and propositional steps were presented for parameters solving in complex circumstance. Firstly, multi-factor and single-factor sensitivity analysis were carried out to classify rock mass and mechanical parameters respectively according to the extent of their effects on deformations. Secondly, based on the results, main influence factors were selected as inversion parameters and taken into a 3D calculating model to get the displacement field and stress field, all of which would be the artificial network training samples together with inversion parameters. Thirdly, taking the real deformations as input for the trained back propagation (BP) neural network, the real material mechanical parameters could be obtained. Finally, the results of trained neural network have been confirmed by field monitoring data and provide a reference to obtain the matter parameters in complicated environment for other similar projects.

Active slide in Tertiary bentonitic claystones, Upper Hat Creek, British Columbia

1986 ◽  
Vol 23 (2) ◽  
pp. 164-173 ◽  
Author(s):  
G. E. Rawlings
Keyword(s):  
British Columbia ◽  
Preventive Measures ◽  
Back Analysis ◽  
Panama Canal ◽  
Open Pit ◽  
Failure Plane ◽  
Debris Slide ◽  
Field Investigations ◽  
Engineering Significance ◽  
Potential Exploitation

Potential exploitation of the 500 m thick coal deposit at Upper Hat Creek, British Columbia, required detailed investigation of the sequence of Tertiary tuffaceous rocks surrounding the coal and the overlying surficial materials. Studies have shown that extensive bentonitic slide deposits partially cover the coal body on the west side of Hat Creek valley; part of this area is currently active. A translational debris slide of approximately 17 × 106 m3 volume and 2 km length is moving across the northwest boundary of the proposed pit into the valley bottom.Detailed field investigations complemented by laboratory testing have defined the basal plane of sliding and permitted a back-analysis to be made. From measured piezometric pressures, the mobilized shear strength on the failure plane is calculated to be [Formula: see text], cr′ = 0, which is largely in accord with laboratory test results.Slope stability in thick montmorillonite-rich claystones/siltstones is known to present difficulties, as evidenced by the Panama Canal excavations. Consideration is given to the engineering significance of bentonitic slides and preventive measures that might be adopted in their control. Key words: active slide, Tertiary, claystone, montmorillonite, open pit, coal, monitoring, residual strength, piezometric pressures.

scholarly journals Stability of an abandoned siderite mine: A case study in northern Spain

2021 ◽  
Vol 13 (1) ◽  
pp. 359-376
Author(s):  
Emilio Trigueros ◽  
Manuel Cánovas ◽  
Javier Arzúa ◽  
Manuel Alcaraz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Element Method ◽  
Back Analysis ◽  
Underground Mine ◽  
Open Pit ◽  
Northern Spain ◽  
Iron Carbonate ◽  
Element Method

Abstract Bodovalle is an iron carbonate mine located in Gallarta (near Bilbao, northern Spain), which is currently in the closure stage. The deposit was first exploited as an open-pit mine and later as an underground mine. The underground mine currently has 40 large rooms with rib pillars, occupying an area of 2,000 m long by 600 m wide. Room depth is around 200 m. The main geotechnical incident occurred in the NW1N zone, where an over-exploited rib pillar in poor condition was partially removed, leaving a 70-m roof span that eventually collapsed in 1999, resulting in a surface crater measuring 60 m in diameter. The collapse was preceded by noises and movements detected outside the mine. The subsidence was improved by means of infilling and monitoring. In 2014, residents living in homes built over the abandoned mine rooms detected very loud noises similar to those of 1999. The article describes a stability review carried out using advanced numerical methods (finite element method and boundary element method) and the geomechanical parameters obtained from a back analysis of the 1999 collapse.

scholarly journals Correlations of geotechnical monitoring data in open pit slope back-analysis -A mine case study

2021 ◽  
Vol 121 (10) ◽  
pp. 1-8
Author(s):  
A.F. Silva ◽  
J.M.G. Sotomayor ◽  
V.F.N. Torres
Keyword(s):  
Slope Failure ◽  
Variable Parameter ◽  
Back Analysis ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Monitoring Data ◽  
Open Pit ◽  
Strength Reduction Factor ◽  
Maximum Deformation ◽  
Geotechnical Monitoring

Geotechnical monitoring plays an important role in the detection of operational safety issues in the slopes of open pits. Currently, monitoring companies offer several solutions involving robust technologies that boast highly reliable data and the ability to control risky conditions. The monitoring data must be processed and analysed so as to allow the results to be used for several purposes, thereby providing information that can be used to manage operational actions and optimize mining plans or engineering projects. In this work we analysed monitoring data (pore pressure and displacement) and its correlation with the tension and displacement of the mass of an established failure slope calculated using the finite element method. To optimize the back-analysis, a Python language routine was developed using input data (point coordinates, parameter matrix, and critical section) to use software with the rock mass parameters (cohesion, friction angle, Young's modulus, and Poisson's ratio). For the back-analysis, the Mohr-Coulomb criterion was applied with the shear strength reduction technique to obtain the strength reduction factor. The results were consistent with both the measured displacements and the maximum deformation contours, revealing the possible failure mechanism, allowing the strength parameters to be calibrated according to the slope failure conditions, and providing information about the contribution of each variable (parameter) to the slope failure in the study area.

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