scholarly journals Stability of Three-Dimensional Slurry Trenches with Inclined Ground Surface: A Theoretical Study

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Xiao-Fei Jin ◽  
Shu-Ting Liang ◽  
Xiao-Jun Zhu
Keyword(s):  
Safety Factor ◽  
Three Dimensional ◽  
Ground Surface ◽  
Theoretical Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Coulomb Type ◽  
The Stability ◽  
Inclined Angle ◽  
2D And 3D

Stability of slurry trenches is an important issue during the construction of the groundwater cutoff walls and diaphragm walls, and thus gradually draws attention. In this paper, a theoretical method for a three-dimensional trench model with an inclined ground was proposed. Based on the Coulomb-type force equilibrium, a safety factor assessing the stability was derived. The results showed that the existing two-dimensional model was conservative compared to the present three-dimensional model; concretely, a greater inclined angle of the inclined ground and trench length decreased the safety factor. This work could be used to assess the trench stability for both 2D and 3D cases with inclined ground surfaces.

An Improved Design of the Manipulator on Automatic Tool Changer

2012 ◽  
Vol 591-593 ◽  
pp. 259-262
Author(s):  
Yan Sheng Li ◽  
Yan Heng Zhang ◽  
Han Xu Sun ◽  
Hai Yang Dong ◽  
Shun Li Zhao
Keyword(s):  
Limit State ◽  
Three Dimensional ◽  
Output Curve ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Improved Design ◽  
The Stability

The tool falling and vibration faults often occur in the process of tool changing, In order to improve the stability of the tools on automatic tool changer, a new structure of the manipulator is presented. The new manipulator contains two-point locking instead of the original one-point locking, and the tools can be clamped more tightly. When the old manipulator is slotting the tool, the forces are analyzed, and the working load and parameters is determined by calculating and analyzing the output curve of manipulator. The three-dimensional model is built in ADMS, and the validity of the new designed manipulator is verified by the simulation in a limit state. The simulation result shows that the new manipulator can increase the ability of tool clamping effectively.

scholarly journals Calibration of a Three-dimensional slope stability evaluation in Brazilian iron open pit mine

2021 ◽  
Author(s):  
Vidal Félix Navarro Torres ◽  
Rodrigo Dockendorff ◽  
Juan Manuel Girao Sotomayor ◽  
Cristian Castro ◽  
Aristotelina Ferreira da Silva
Keyword(s):  
Three Dimensional ◽  
Structural Features ◽  
Open Pit ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Strength Parameters ◽  
Dimensional Section ◽  
The Stability ◽  
Evaluation Techniques

Abstract It has historically been frequent among geotechnical practitioners, that the stability analysis of the slopes of an open pit is performed using a two dimensional section representing the highest and steepest walls within a certain geological setting. However, the literature shows that to predict rupture events in an open pit, a three-dimensional analysis would better represent the actual conditions, as the spatial distribution of the lithology and the structural features play an important role when defining the stability of the slopes. This paper presents the case study of an open it located in Brazil, which experienced instabilities between the years 2001-2019. An evaluation of the behavior of the open pit was performed by calibrating the strength parameters to represent the best documented rupture events. The three-dimensional model was made using the FLAC3D software. The results show that there is a good correlation between the results of the model and the reports of past instabilities. Finally, recommendations are presented for the inter-ramp angles for each lithology based on the calibrated stability analyzes performed. This work seeks to contribute to the knowledge in evaluation techniques for the three-dimensional behavior of open pits.

Lightweight Design for Hydraulic Support

2010 ◽  
Vol 450 ◽  
pp. 79-82
Author(s):  
Xin Zhang ◽  
Jian Wu Zhang ◽  
Qing Liang Zeng ◽  
Cheng Long Wang
Keyword(s):  
Lightweight Design ◽  
Three Dimensional ◽  
Bottom Plate ◽  
Three Dimensional Model ◽  
Hydraulic Support ◽  
Element Analysis ◽  
Side Plate ◽  
Mining Condition ◽  
The Stability ◽  
Inclined Angle

In large inclined angle mining condition, in order to decrease the effect of sliding force, a lightweight design for hydraulic support is presented in this paper. Taking minimum mass of top beam as optimization objective, the three-dimensional model of it is built firstly. The whole top beam is simplified into top plate, side plate, bottom plate and main reinforcement on the premise of unchanging its topology configuration, and only strength constraint is chosen as constraint, which reduces the number of constraint functions and calculation cycles. By means of ANSYS zero-order optimization module, the mass of top beam is decreased about 16.9%. Finally, the optimal lightweight structure is fully evaluated under the same load as pre-optimization, and finite element analysis results prove that its stress and strain satisfy the need of strength. This lightweight design measure is used in the practical manufacturing with a lower cost of materials, which also increases the stability of hydraulic support in large inclined angle mining condition.

scholarly journals Evaluation of Slope Stability Considering the Preservation of the General Patrimonial Cemetery of Guayaquil, Ecuador

Geosciences ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 103 ◽  
Author(s):  
Fernando Morante ◽  
Maribel Aguilar ◽  
Gonzalo Ramírez ◽  
Roberto Blanco ◽  
Paúl Carrión ◽  
...  
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Three Dimensional ◽  
Loss Of Stability ◽  
Dimensional Model ◽  
High Susceptibility ◽  
Three Dimensional Model ◽  
Practical Procedure ◽  
Slope Mass Rating ◽  
Made In

Inefficient blasting techniques and poor closure management of the old quarry that existed during the 1970s in the area of the actual General Patrimonial Cemetery of Guayaquil resulted in an almost vertical slope of approximately 50 m in height and an intense induced fracturing that weakened the rock mass. This led to the loss of stability and increased material detachment, which damaged the infrastructure of the graveyard representing a risk to visitors and workers. The aim of this research is to evaluate the slope stability through a geotechnical analysis that allows decision-making to recover and preserve the safety of the area. In this work, we used structural measurements and observations made in the field, as well as a three-dimensional model of the slant generated by photographs taken by a drone. Slope Mass Rating (SMR) and Chinese Slope Mass Rating (CSMR) rankings were used to evaluate stability, susceptibility to rockfall was determined using a theoretical–practical procedure, and the safety factor was calculated using the Morgenstern–Price method. The analysis of the geomechanical classifications yielded a low stability value of the slope, which was in accordance with the high susceptibility to rockfall and with the low safety factor. Based on these results, we recommend the application of systematic bolt and shotcrete for stabilization.

The assembly of ionic currents in a thalamic neuron I. The three-dimensional model

1989 ◽  
Vol 237 (1288) ◽  
pp. 267-288 ◽  
Keyword(s):  
Three Dimensional ◽  
State Diagram ◽  
Ionic Currents ◽  
Stability Diagram ◽  
Repetitive Firing ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Two Dimensional Model ◽  
The Stability

We have previously discussed qualitative models for bursting and thalamic neurons that were obtained by modifying a simple two-dimensional model for repetitive firing. In this paper we report the results of making a similar sequence of modifications to a more elaborate six-dimensional model of repetitive firing which is based on the Hodgkin–Huxley equations. To do this we first reduce the six-dimensional model to a two-dimensional model that resembles our original two-dimensional qualitative model. This is achieved by defining a new variable, which we call q . We then add a subthreshold inward current and a subthreshold outward current having a variable, z , that changes slowly. This gives a three-dimensional ( v, q, z ) model of the Hodgkin–Huxley type, which we refer to as the z -model. Depending on the choice of parameter values this model resembles our previous models of bursting and thalamic neurons. At each stage in the development of these models we return to the corresponding seven-dimensional model to confirm that we can obtain similar solutions by using the complete system of equations. The analysis of the three-dimensional model involves a state diagram and a stability diagram. The state diagram shows the projection of the phase path from v, q, z space into the v, z plane, together with the projections of the curves ż = 0 and v̇ = q̇ = 0. The stability of the points on the curve v̇ = q̇ = 0, which we call the v, q nullcurve, is determined by the stability diagram. Taken together the state and stability diagrams show how to assemble the ionic currents to produce a given firing pattern.

Three-Dimensional Simulation of the Influences of Operational Parameters on Stability of Formation-Cement Sheath-Casing Combination

2020 ◽  
Vol 980 ◽  
pp. 525-546
Author(s):  
Yong Wen Yuan ◽  
Yan Jun Cheng ◽  
Jin Xin Zhu ◽  
Liu Yi Li
Keyword(s):  
Cross Section ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Physical Parameters ◽  
Dimensional Model ◽  
Operational Parameters ◽  
Three Dimensional Model ◽  
Cement Sheath ◽  
The Stability ◽  
Casing Pressure

At present, most of the studies of the stability of the formation-cement sheath-casing combination have been mainly based on the plane, and the three-dimensional model established is only one example. There is no systematic study of the influence of physical parameters and process parameters on the stability of the combined body under the three-dimensional model and the action of triaxial crustal stress. Through the establishment of three-dimensional formation-cement sheath-casing linear elastic combination model, we can study the influence of operational parameters (cement sheath pressure, casing cross section pressure, inner casing pressure, ellipticity of borehole, centrality of casing, thickness of cement sheath) by the two interfaces’ Von Mises stress and the total displacement of the combination body. It is pointed out that the pressure of cement sheath, and casing cross section pressure have no effect on the stability of formation, cement sheath and casing; The higher the ellipticity of the borehole, the eccentricity of the casing (position 1, 2) and the thickness of the cement sheath, the higher the stability of the second interface of the cementing; The higher the inner casing pressure and the eccentricity of the casing(position 3), the lower the stability of the second interface of the cementing; The higher the eccentricity of the casing (position 2,3) and the thickness of the cement sheath, the higher the stability of the first interface of the cementing; The higher the inner casing pressure, the eccentricity of the casing (position 1) and the ellipticity of the borehole, the lower the stability of the first interface of the cementing; The higher the eccentricity of the casing (position 2,3) and thickness of the cement sheath, the higher the stability of the casing; The higher the inner casing pressure, the ellipticity of the borehole and the eccentricity of the casing(position 1), the lower the stability of the casing. Through this study, according to the formation stress, the formation physical parameters (elastic modulus, Poisson's ratio, density), optimize the operational parameters, ensure the long-term integrity of the combination.

scholarly journals A pedagogical overview on 2D and 3D Toric Codes and the origin of their topological orders

2019 ◽  
Vol 32 (02) ◽  
pp. 2030002
Author(s):  
M. F. Araujo de Resende
Keyword(s):  
Ground State ◽  
Three Dimensional ◽  
Topological Order ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Dimensional Torus ◽  
Three Dimensional Model ◽  
2D And 3D ◽  
New Situation ◽  
Toric Code

In this work, we will show how the topological order of the Toric Code appears when the lattice on which it is defined discretizes a three-dimensional torus. In order to do this, we will present a pedagogical review of the traditional two-dimensional Toric Code, with an emphasis on how its quasiparticles are conceived and transported. With that, we want to make clear not only how all these same quasiparticle conception and transportation fit into this three-dimensional model, but to make it clear how topology controls the degeneracy of ground state in this new situation.

scholarly journals Investigations on the Stability of a Two-Wheeled Vehicle with a Tendency to Topple Sideways

2021 ◽  
Vol 2070 (1) ◽  
pp. 012183
Author(s):  
R Sidharth ◽  
V K Pravav ◽  
G Nitheesh Kumar ◽  
Pramod Sreedharan ◽  
G Gayathri
Keyword(s):  
Sliding Mode ◽  
Three Dimensional ◽  
Sliding Mode Controller ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Wheeled Vehicle ◽  
The Stability ◽  
Wheeled Vehicles

Abstract Two-wheeled vehicles are the most commonly used means of transportation. Every day many unspoken tragedies are happening on the roads that kill the hope of many families. The primary cause of this is the inherent instability of the two-wheeled vehicle. In this paper, the precession effect of the gyroscope is used to prevent the sideway toppling of the bicycle. When the bicycle begins to tilt, the torque created by the gyroscope’s precession effect is applied to the gimbal, and the ensuing reaction moment keeps the bicycle upright. The movements of a bicycle with a gimbal placed on the bottom are measured, and a three-dimensional model with a sliding mode controller is created and simulated.

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