scholarly journals Applicability of failure strain for the stability evaluation of square pillars in room and pillar mining

2017 ◽  
Author(s):  
Gian Napa-Garcia ◽  
Vidal Navarro Torres
Keyword(s):  
Failure Strain ◽  
Stability Evaluation ◽  
Room And Pillar Mining ◽  
Pillar Mining ◽  
The Stability

Optimization of Stope Structural Parameters in Phosphorite Mine and its Stability Analysis

2014 ◽  
Vol 580-583 ◽  
pp. 1268-1272 ◽  
Author(s):  
Xiang Xing Li ◽  
Ke Gang Li
Keyword(s):  
Structural Parameters ◽  
Simulation Method ◽  
Surrounding Rock ◽  
Room And Pillar Mining ◽  
Rock Stability ◽  
Mining Depth ◽  
Ground Pressure ◽  
Pillar Mining ◽  
Phosphate Deposit ◽  
The Stability

A mine plans to exploit the low dip thin phosphate deposit by room-and-pillar mining. But a township highway is just above the orebody, and its distance is only 80m, in order to better control the ground pressure in stopes and ensure the operation security, the size of room and pillar must be reasonably designed to maintain the stability of stopes and surrounding rock. The 3D-σ numerical simulation method was applied to analyze the surrounding rock stability in different stope structure parameters. The results show that when holding the size of pointed prop unchanged, the surrounding rock stability would decline with the increase of room width and pillar spacing, for security, the mining plan, the pointed prop is 3×3 m, the stope width and pillar spacing is not more than 9 m, were considered to be one of the optimal. In addition, it is important to emphasize that if the mining depth exceeds 300m, some methods, such as decreasing the spacing of stope and pointed props or increasing the pillar size, need to be taken to avoid the stope instability caused by greater ground pressure.

scholarly journals Determination of the stability of residual pillars in a room-and-pillar mining goaf under eccentric load

2021 ◽  
Vol 7 ◽  
pp. 9122-9132
Author(s):  
Nan Zhou ◽  
Erbao Du ◽  
Meng Li ◽  
Jixiong Zhang ◽  
Chaowei Dong
Keyword(s):  
Eccentric Load ◽  
Room And Pillar Mining ◽  
Pillar Mining ◽  
The Stability

scholarly journals EVALUATION OF THE STABILITY OF A TEMPORARY PILLAR WHEN MIINING ORE HORIZONS WITH BACKFILLING AND CAVING

2021 ◽  
Vol 2 (3) ◽  
pp. 123-134
Author(s):  
Sergey Yu. Vasichev ◽  
Alexander A. Neverov
Keyword(s):  
Raw Materials ◽  
Ore Deposits ◽  
Geomechanical Model ◽  
Mining System ◽  
Room And Pillar Mining ◽  
Mining Front ◽  
Pillar Mining ◽  
The Stability ◽  
Enclosing Rocks ◽  
Safe Mining

A method is proposed for mining thick and flat ore deposits at great depths in conditions of a decline in the value of extracted mineral raw materials. It is found that safe mining with solidifying backfill and caving is achieved by determining the parameters of stable spans of rooms, in place of which artificial supports and temporary ore pillars are formed. These pillars are recovered with a lag behind room-and-pillar mining by caving of ore and enclosing rocks. It is shown that, depending on the type of geomechanical model of geomedium and orientation of the initial natural stresses acting in the rock mass relative to the mining front, the field of application of the mining system is limited by the depth and parameters of excavation. Predictive areas of possible rock failure are determined applicably to rock masses with different degree of disturbance.

scholarly journals Stability Evaluation Method of Hole Wall for Bored Pile under Blasting Impact

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 79
Author(s):  
Qiuwei Yang ◽  
Zhikun Ba ◽  
Zhuo Zhao ◽  
Xi Peng ◽  
Yun Sun
Keyword(s):  
Pile Foundation ◽  
Evaluation Method ◽  
Impact Load ◽  
Stability Evaluation ◽  
Foundation Construction ◽  
Concentration Problem ◽  
Hole Wall ◽  
Failure Theory ◽  
Collapse Failure ◽  
The Stability

Blasting impact load may be encountered during the construction of some pile foundation projects. Due to the effect of blasting impact, hole collapse can easily occur in the hole-forming stage of pile foundation construction. In order to prevent hole collapse, it is very necessary to evaluate the stability of a pile hole wall before pile foundation construction. The calculation of hole collapse can usually be attributed to an axisymmetric circular hole stress concentration problem. However, the existing collapse failure theory of pile hole hardly considers the effect of blasting impact load. In view of this, this paper proposes the stability evaluation method of a pile hole wall under blasting impact. Compared with the existing collapse failure theory, the proposed method fully considers the effect of blasting impact stress. Using Mohr–Coulomb strength theory and symmetry analysis, the strength condition of collapse failure is established in this work for accurate evaluation of the stability of a hole wall. The proposed stability evaluation method is demonstrated by a pile foundation construction project of a bridge. Moreover, a shaking table test on the pile hole model was performed to verify the proposed method by experimental data. The results indicate the effectiveness and usability of the proposed method. The proposed method provides a feasible way for the stability analysis of a pile hole wall under blasting impact.

scholarly journals Modeling of the emulsion stability using fractal dimensions

2008 ◽  
Vol 14 (3) ◽  
pp. 153-158 ◽  
Author(s):  
Snezana Pasalic ◽  
Predrag Jovanic
Keyword(s):  
Emulsion Stability ◽  
Fractal Dimensions ◽  
Ccd Camera ◽  
Stability Evaluation ◽  
Stable States ◽  
Water Emulsion ◽  
Box Counting Method ◽  
The Stability ◽  
The Moment ◽  
Life Circle

There are many developed strategies in the emulsion stability evaluation, for purpose of determining the life circle of emulsions. Most of them are based on the reological properties of the emulsions. There are very few which relay on the direct emulsion observations. In this paper we present the developed method for the emulsion stability evaluation by the direct observation of optical properties. As the stability quantification measure we propose the fractal dimension approach. The method is based on the measure of the emulsion transmittance properties, which are directly dependent on the emulsion stability at the moment of measurement. As the test emulsion the oil in the water emulsion was used. The system is classified as the stable emulsion and our intention was to find the moment when the emulsion starts to break. The emulsion transmittance properties were measured using an acquisition system, consisting of a CCD camera and a fast PC configuration equipped with the capturing software. The fractal dimensions were determined by the so called box counting method. The experimental emulsions were measured continuously within the period of 1200 h, from the moment of the emulsion creation. The changes of fractal dimensions were observed which indicates that the emulsion changed its state and therefore the stability during the time. Three regions of the emulsion life circle were divided according to the fractal dimensions measurement, which can be connected with the stable, unstable, and meta-stable states of the emulsion life circle. In the end, the model of the emulsion behavior was developed for the purpose of quantifying the changes in the experimental emulsion.

scholarly journals Quantum Mechanical-Based Stability Evaluation of Crystal Structures for HIV-Targeted Drug Cabotegravir

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7178
Author(s):  
Yanqiang Han ◽  
Hongyuan Luo ◽  
Qianqian Lu ◽  
Zeying Liu ◽  
Jinyun Liu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ab Initio ◽  
Crystal Structures ◽  
Structure Prediction ◽  
Hiv Infections ◽  
Integrase Inhibitor ◽  
Hiv Integrase ◽  
Stability Evaluation ◽  
The Stability ◽  
Long Acting

The long-acting parenteral formulation of the HIV integrase inhibitor cabotegravir (GSK744) is currently being developed to prevent HIV infections, benefiting from infrequent dosing and high efficacy. The crystal structure can affect the bioavailability and efficacy of cabotegravir. However, the stability determination of crystal structures of GSK744 have remained a challenge. Here, we introduced an ab initio protocol to determine the stability of the crystal structures of pharmaceutical molecules, which were obtained from crystal structure prediction process starting from the molecular diagram. Using GSK744 as a case study, the ab initio predicted that Gibbs free energy provides reliable further refinement of the predicted crystal structures and presents its capability for becoming a crystal stability determination approach in the future. The proposed work can assist in the comprehensive screening of pharmaceutical design and can provide structural predictions and stability evaluation for pharmaceutical crystals.

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