Stability Effect to Railway Tunnel of Underground Mining Using ABAQUS

2011 ◽  
Vol 361-363 ◽  
pp. 236-240
Author(s):  
Li Wei Yuan ◽  
Long Zhe Jin

The paper used the software ABAQUS to the numerical simulation research of the strata movement process during the underground mining according to the actual characteristics of certain mine. Through the research and theory analysis of numerical simulation, the numerical value of deformation in horizontal and vertical direction of the strata movement at the railway tunnel is included. It showed that the exploitation of No.2 ore body would not affect the safety of railway tunnel nearly the mine, which provide decision-making basis for the railway departments and mining enterprises, reduce the waste of resources.

2013 ◽  
Vol 448-453 ◽  
pp. 3884-3887 ◽  
Author(s):  
You Ling Fang

The process of fractures developing of coal and rock and overlying strata movement is a temporal dynamic evolution process. In this paper, based on the research object a working face of a mine, using the UDEC numerical simulation software to research the movement of the working face upper strata in mining process, the results showed that the overlying strata forms "vertical three zones" in the vertical direction from bottom to top. Overlying strata above the goaf displays a fracture table with a trapezoid shape entirely; the cut side of the fracture angle is slightly larger than the working face side of the fracture angle. Numerical simulation calculation of the height of two zones will get a close consistent result to empirical formula. The conclusions have important guiding significance for reasonable arrangement of the gas exploitation.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jiabo Geng ◽  
Qihang Li ◽  
Xiaoshuang Li ◽  
Tao Zhou ◽  
Zhifang Liu ◽  
...  

This study is based on the engineering background of pit no. 2 in Jinning Phosphate Mine, China. In order to systematically analyze the movement, deformation, and failure laws of surrounding rocks in underground stopes. The room and pillar method is used to excavate and stop the ore bodies in the mining area. Combined with the similar physical model experiments and discrete element MatDEM numerical simulations, it reveals the deformation and failure laws and evolution characteristics of the surrounding rock of the stope in the process of converting from open-pit to underground mining. The results show the following: (1) Along the inclination of the ore body, the farther the horizontal and vertical displacements are from the underground stope, the less the impact of mining stress. On the other hand, along the inclined vertical direction of the ore body, the farther the measuring point is from the stope, the smaller the range of mining influence will be. (2) In the process of ore body recovery, the rupture of the overlying strata of the stope has an obvious layered structure, with collapse zones, fissure penetrating zones, and microfracture loosen zones appearing from the bottom to top. In addition, the movement and destruction of the overlying strata of the entire stope is an “elliptical arch.” Therefore, the results of similar simulation experiments and numerical simulation are basically consistent.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiaoshuang Li ◽  
Jian Song

Ground pressure characteristics of the ore body and the overburden deformation of the stope depend highly on the combined influence of geological conditions and mining disturbance. The ore body inclination, as a natural geological factor, has a nonnegligible effect on the underground mining. The ore angle plays a great role in the stress distribution of the overlying rock layer, resulting in the movement and destruction of the rock layer. The variation of the ore angle dominates the stress distribution of the overburden rock, the forms of movement, destruction, and the surface moving basin. Here, taking the geological mining conditions of the deep ore body mining in Jinning Phosphate Mine as the engineering background, we adopt a similar material ratio scheme of each rock layer in the mining area via the similarity theory and the principle of orthogonal experiment. We conduct systematic study on the strata movement, mining failure characteristics, and movement of the overlying rock in stope using a similar simulation test under two different ore angles of 20° and 50°. We found that, as the ore body inclination increases from 20° to 50°, the overburden unloading area of the stope extending to the deep part of the rock layer in the vertical direction is more obvious and its shape is more asymmetric about the stope center. The unloading area is more concentrated in the middle and upper part of the stope, while the upward development trend is more obvious. The relevant results can provide a certain reference for the underground mining of the mines and those with similar conditions.


2013 ◽  
Vol 318 ◽  
pp. 460-464
Author(s):  
Tao Ping Chen ◽  
Chao Jiang ◽  
Li Li Wang

Conceptual models of lateral accretion interbed (the point bar lateral sandbody model contains three lateral accretion interbed .And the lateral accretion interbeds extends to two-thirds of reservoir thickness)is builded making use of numerical simulation software Eclipse. The effect of injection water on water drive recovery is analysised. The location of remaining oil enrichment is also determined. Horizontal well is placed in remaining oil enrichment and its vertical direction and horizontal hole section are optimization. Horizontal well and vertical well are combined to exploit residual oil. Results indicates that: Injectiong water in the direction of lateral accretion interbed can obtain higher water drive recovery than in the opposite direction. The closer to top the horizontal well is , the greater recovery enhancement values is.Horizontal hole section starts from the location of four-fifths of lateral sandbody I left and terminats nine-tenths of lateral sandbody III, where the recovery is highest. Horizontal well is placed after vertiacal well injecting polymer in which recovery can increase 9.8%. According to numerical simulation optimization results, we have made a physical model with lateral accretion interbeds to do experiments. Numerical simulation results agree with experimental results. Hence horizontal and vertical well uinting together can exploit the remaining oil of lateral accretion interbed effectively .


BMJ Open ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. e030430
Author(s):  
Thomas Ott ◽  
Jascha Stracke ◽  
Susanna Sellin ◽  
Marc Kriege ◽  
Gerrit Toenges ◽  
...  

ObjectivesDuring a ‘cannot intubate, cannot oxygenate’ situation, asphyxia can lead to cardiac arrest. In this stressful situation, two complex algorithms facilitate decision-making to save a patient’s life: difficult airway management and cardiopulmonary resuscitation. However, the extent to which competition between the two algorithms causes conflicts in the execution of pivotal treatment remains unknown. Due to the rare incidence of this situation and the very low feasibility of such an evaluation in clinical reality, we decided to perform a randomised crossover simulation research study. We propose that even experienced healthcare providers delay cricothyrotomy, a lifesaving approach, due to concurrent cardiopulmonary resuscitation in a ‘cannot intubate, cannot oxygenate’ situation.DesignDue to the rare incidence and dynamics of such a situation, we conducted a randomised crossover simulation research study.SettingWe collected data in our institutional simulation centre between November 2016 and November 2017.ParticipantsWe included 40 experienced staff anaesthesiologists at our tertiary university hospital centre.InterventionThe participants treated two simulated patients, both requiring cricothyrotomy: one patient required cardiopulmonary resuscitation due to asphyxia, and one patient did not require cardiopulmonary resuscitation. Cardiopulmonary resuscitation was the intervention. Participants were evaluated by video records.Primary outcome measuresThe difference in ‘time to ventilation through cricothyrotomy’ between the two situations was the primary outcome measure.ResultsThe results of 40 participants were analysed. No carry-over effects were detected in the crossover design. During cardiopulmonary resuscitation, the median time to ventilation was 22 s (IQR 3–40.5) longer than that without cardiopulmonary resuscitation (p=0.028), including the decision-making time.ConclusionCricothyrotomy, which is the most crucial treatment for cardiac arrest in a ‘cannot intubate, cannot oxygenate’ situation, was delayed by concurrent cardiopulmonary resuscitation. If cardiopulmonary resuscitation delays cricothyrotomy, it should be interrupted to first focus on cricothyrotomy.


2021 ◽  
Vol 1838 (1) ◽  
pp. 012061
Author(s):  
Qihui Zhou ◽  
Zhanjun Huang ◽  
Yong Wu ◽  
Huipeng Zhang ◽  
Yufeng Shi ◽  
...  

2021 ◽  
pp. 019394592110216
Author(s):  
Audrey Rosenblatt ◽  
Michael Kremer ◽  
Olimpia Paun ◽  
Barbara Swanson ◽  
Rebekah Hamilton ◽  
...  

Millions of young children undergo surgery and anesthesia each year, yet there is a lack of scientific consensus about the safety of anesthesia exposure for the developing brain. Also poorly understood is parental anesthesia-related decision-making and how neurotoxicity information influences their choices. The theoretical model of parental decision-making generated in this research explicates this process. Interviews with 24 mothers yielded a theoretical framework based on their narratives developed using a qualitative grounded theory analysis. Five major themes emerged from these interviews: emotional processing, cognitive processing, relationships as resources, the mother/child dyad, and the health care context. Mothers described a non-linear, iterative process; they moved fluidly through emotional and cognitive processing supported by relationships as resources and influenced by the health care context. A key element was the subtheme of the medical translator, an individual who provided context and information. The mother/child dyad grounded the model in the relationship with the child.


2018 ◽  
Vol 60 ◽  
pp. 00029 ◽  
Author(s):  
Vladimir Golik ◽  
Yuriy Razorenov ◽  
Volodymyr Morkun ◽  
Nataliia Morkun

The article is aimed at improving development mining to prepare an ore body for stoping by access ramps to provide comfortable conditions and high technical and economic indices in underground mining. Efficient parameters of underground mining are chosen in the course of simulating data on the mining theory and practice considering ore losses and dilution on the basis of critical analysis of uranium mining enterprises’ activities. The research provides data on geological and engineering zoning of an ore deposit and physical-mechanical properties of ore bearing rocks. The advanced experience is systemized and there is provided system analysis of modern development mining schemes with access ramps (ring, spiral, one-way inclined, central inclined and across the strike). The research recommends schemes of development mining and substantiates their advantages. There are quantitative indices of physical simulation of development variants as to drawn ore quality according to criteria of soil location in ore draw points. The scientific novelty implies developing the criterion of optimality and ranking variants of development mining according to technical-economic and geomechanical indices considering some technological factors as well as the number of stopes operating simultaneously on the level. The study consists in increasing authenticity of development projects through applying complex schemes of access ramps according to the complex criterion of increasing mining depths, equipment application, ventilation and underground mine capacity.


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