scholarly journals Numerical Simulation Study on the Influence of Mine Earthquake on the Bolt Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiaoqian Zhang ◽  
Heng Zhang ◽  
Chengmin Wei
Keyword(s):  
Safety Factor ◽  
Coal Mine ◽  
Axial Stress ◽  
Microseismic Monitoring ◽  
Earthquake Hypocenter ◽  
Mine Roadway ◽  
Bolt Stress ◽  
The Stability ◽  
The Impact ◽  
Bolt Support

Mine earthquake, as an underground disaster that occurs frequently, has a great impact on coal mine roadway and support. The stability analysis of the bolt support in roadway under different mine earthquake magnitudes is a key issue to be solved urgently in mining fields. This paper attempted to simulate the occurrence state of mine earthquake with explosive blasting process and verified it with actual coal mine microseismic monitoring data. ANSYS/LSDYNA software was used to analyze the impact of magnitude and location of mine earthquake hypocenter on the stability of bolt support and the dynamic stress characteristics of bolt. The results showed that with the increase in source energy of mine earthquake, the damage location of bolt mainly appears in the front of bolt and the loading position has no obvious change, but there is stress wave superposition effect, which deepens the damage of bolt. The bolts in the middle of the lane and the middle of the roof are greatly affected, so the support strength should be strengthened in these places. In addition, this paper compared the safety factor of bolt and the supporting effect of different schemes from three aspects such as roof subsidence, axial stress of bolt, and safety factor of bolt and then put forward a more economical and effective supporting scheme.

scholarly journals Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jucai Chang ◽  
Kai He ◽  
Zhiqiang Yin ◽  
Wanfeng Li ◽  
Shihui Li ◽  
...  
Keyword(s):  
Coal Mine ◽  
Stability Index ◽  
Surrounding Rock ◽  
Full Length ◽  
Control Effect ◽  
Support Design ◽  
Rock Stability ◽  
Working Face ◽  
The Stability ◽  
Bolt Support

In view of the influence of mining stress on the stability of the surrounding rock of inclined roof mining roadways in deep mines, the surrounding rock stability index is defined and solved based on the rock strength criterion and the stress distribution. The mining roadway of the 17102(3) working face of the Pansan Coal Mine is used as the engineering background and example. The surrounding rock’ stabilities under the conditions of no support and bolt support are analyzed according to the surrounding rock’s stability index and the deformation data. The results show that the areas of low wall and high wall instability are 1.68 m2 and 2.12 m2, respectively, and the low wall is more stable than the high wall; the areas of the roof and floor instability are 0.33 m2 and 0.35 m2, respectively, and the roof and floor are more stable than the two sides. During mining, the area of instability greatly increases at first, then decreases to 0, and reaches a maximum value at the peak of the abutment pressure. The stability of the surrounding rock decreases first and then increases. Compared with the end anchoring bolt support, the full-length anchoring bolt support reduces the area of instability to a greater extent, and the full-length anchoring bolt support effect is better. The surrounding rock in the end anchoring zone and the full-length anchoring zone began to deform significantly at 200 m and 150 m from the working face, respectively. This indicates that the control effect of the full-length anchoring bolt support is better and verifies the rationality of the surrounding rock stability index to describe the instability characteristics. This research method can provide a theoretical reference for analysis of the stability characteristics and support design of different cross-section roadways.

scholarly journals Analysis of Stability Factors of Roadway Roof and Determination of Unsupported Roof Distance

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Sen Yang ◽  
Xinzhu Hua ◽  
Xiao Liu ◽  
Chen Li
Keyword(s):  
Influencing Factors ◽  
Geological Conditions ◽  
Mine Roadway ◽  
Flac 3D ◽  
Roof Stability ◽  
Analysis Of Stability ◽  
The Stability ◽  
The Impact ◽  
The Relationship

To determine the impact of influencing factors on unsupported roof stability in coal mine roadway, a mechanical model of the unsupported roof was built. FLAC 3D numerical simulation was utilized to study the stability of the unsupported roof under the influence of the depth of the roadway, the thickness of the roof, and the unsupported-support distance. In view of the key influencing factors, the geological conditions of the site, and the relationship between the tensile stress and tensile strength of the unsupported roof, the maximum unsupported roof distance during roadway excavation was determined. Considering the surplus safety factor of the unsupported roof, the reasonable unsupported roof distance during the excavation of roadway 150802 was finally determined to be 2.08 m. The comprehensive roadway excavation speed increased by 62.7%, achieving a monthly progress over 500 m.

scholarly journals ANALISIS STABILITAS DAN PERKUATAN LERENG MENGGUNAKAN PLAXIS2D DI DESA SUKARESMI, SUKABUMI, JAWA BARAT

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
A'isyah Salimah ◽  
Muhammad Fathur Rouf Hasan ◽  
Suripto Suripto ◽  
Yelvi Yelvi ◽  
Imam H Sasongko
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Retaining Wall ◽  
Soil Surface ◽  
Retaining Walls ◽  
Environmental Damage ◽  
Field Investigations ◽  
Base Transceiver Station ◽  
The Stability ◽  
The Impact

Permukaan tanah tidak semua berbentuk bidang datar, namun memiliki perbedaan ketinggian dan kemiringan pada setiap daerah. Perbedaan ketinggian tanah mampu mengakitbatkan terjadinya pergerakan tanah yaitu longsor. Keberadaan bangunan base transceiver station (BTS) tower di Desa Sukaresmi, Cisaat, Sukabumi yang berada pada daerah lereng curam dengan kondisi retaining wall dan pagar dalam keadaan retak dan mengalami penurunan tanah menjadi salah satu faktor yang mengancam keselamatan. Untuk mengantisipasi dampak kerusakan lingkungan bertambah parah dibutuhkan penanganan khusus. Penelitian ini bertujuan untuk melakukan analisis stabilitas dan perkuatan lereng menggunakan software Plaxis2D. Adapun metode penelitian dilakukan dengan melakukan investigasi lapangan secara langsung, pengujian laboratorium, analisis stabilitas perkuatan lereng dengan software Plaxis2D serta rekomendasi perbaikan drainase. Upaya perkuatan lereng dengan mengganti dan memperdalam retaining wall existing. Hasil perkuatan lereng dapat meningkatkan nilai safety factor menjadi 1,369, nilai ini lebih besar dari safety factor existing sebesar 1,302. Kata kunci: cisaat, longsor, Plaxis2D, stabilitas lereng. The soil surface is believed to have differences in height and slope in each region. The different elevation could cause land movements namely landslides. The existence of tower base transceiver station (BTS) buildings in Sukaresmi Village, Cisaat,  Sukabumi on a deep slope area with cracked retaining walls and fences condition which experienced settlement is one of the factors that threaten safety. To anticipate the impact of environmental damage getting worse requires special handling. The aim  of this study is to analyze the stability and slope reinforcement using Plaxis2D software. The research method is carried out by conducting direct field investigations, laboratory tests, reinforced slope stability analysis with Plaxis2D software and drainage refinement recommendations. Countermeasures to strengthen the slope are done by replacing and deepening the existing retaining wall. The result of this measure is the increase of the safety factor value to 1,369, this value is greater than the value of the existing safety factor of 1,302. Keywords : cisaat, landslide, Plaxis2D, slope stability.

Study on the Role of Geogrid-Reinforced for Fly Ash Retaining Wall Basing on the Analysis of FLAC3D

2011 ◽  
Vol 368-373 ◽  
pp. 599-603
Author(s):  
Wei Shi ◽  
Jin Han ◽  
Yong Bin Li
Keyword(s):  
Fly Ash ◽  
Safety Factor ◽  
Lateral Displacement ◽  
Retaining Wall ◽  
Vertical Displacement ◽  
Design Parameters ◽  
Finite Element Software ◽  
The Stability ◽  
The Impact

Geogrid-reinforced retaining wall is widely used in civil engineering, the role of geogrid reinforcement and the calculations of reinforcement material in the retaining wall design need further refinement.This paper analyzes the fly ash retaining wall with and without reinforcement by using finite element software of FLAC3D,studys the impact of geogrid-reinforced function on the stability of fly ash retaining wall ,gets the design parameters of geogrid-reinforced fly ash retaining wall.The numerical results show that: the fly ash retaining walls' safety factor is lower when its height is greater than 6m,reinforcement is needed for fly ash retaining wall to improve its safety factor to ensure the stability of retaining wall.Simulate and analyze the 8m high geogrid reinforced fly ash retaining wall,the results show that: increasing the reinforcement spacing can increase the lateral and vertical displacement of geogrid reinforced fly ash retaining wall, the maximum vertical displacement of retaining wall is in the upper wall,maximum lateral displacement occurs in the lower parts of the retaining wall;the reasonable distance of 8m high fly ash retaining wall is 0.8m.

scholarly journals Geotechnical Study of The Impact of Groundwater Level For Slope Stability in Coal Mine

2019 ◽  
Vol 1 (1) ◽  
pp. 12-21
Author(s):  
Jioni Santo Frans ◽  
Muhammad Hafizh Nurfalaq
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Safety Factor ◽  
Coal Mine ◽  
Groundwater Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Slope Angle ◽  
Primary Data ◽  
The Impact

Rock mass has force equilibrium which can be disturbed due to changes in rock mass conditions, both by naturally as well as human activities. In response, rock masses could have instability to reach new equilibrium and trigger landslides. Unstable slopes will affect the safety, economic and social factors. Groundwater has its own problems in mining management. Pore water pressure can cause uplift force and reduce the strength of the rock mass forming slopes and affect the slope stability. The study area has groundwater level relatively close to surface and causes the slope to be in nearly saturated condition. This research aims to study of the effect of groundwater levels on the stability of coal mine slopes in the study area. The research method includes collecting primary data through field observations to collect related technical data and secondary data collection through literature studies. Slope stability analysis was carried out to obtain recommendations with a minimum Safety Factor of 1.30. The results showed the ground water level has an inverse relationship to Safety Factor value. The recommendation is  depressurisation using drain holes. The target of groundwater level reduction in the mine wall is RL+40 in the sidewall area and RL+65 in the highwall area. Another alternative is is by resloping the overall slope angle of the mine wall in the study area. The mine slope is recommended for layback with an overall slope angle of around 24 °.

scholarly journals The Impact of the Low Throw Fault on the Stability of Roadways in a Hard Coal Mine

2017 ◽  
Vol 39 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Piotr Małkowski ◽  
Łukasz Ostrowski ◽  
Piotr Bachanek
Keyword(s):  
Fault Zone ◽  
Coal Mine ◽  
Geological Structure ◽  
Hard Coal ◽  
Convergence Results ◽  
Roadway Stability ◽  
Special Measuring ◽  
The Stability ◽  
Degree Of Convergence ◽  
The Impact

Abstract Ensuring roadways stability in hard coal mines is one of the main challenges faced by engineers. A changeable geological structure have caused the roadway’s conditions to vary, thus influencing its stability. One of the causes of those changes is the presence of a previously undiscovered fault zone (small faults crossed the roadway) within which a significant convergence or support deformation may occur. The paper presents the impact of low throw faults on the degree of convergence of roadways. Convergence is determined for two roadways in the hard coal mine. A special measuring stations have been installed in one of the roadways, and they have carried out constant measurements for 15 months. In the other roadway, the degree of convergence has been determined on the basis of an on-site verification and comparison of the measurements obtained and the initial values, based on the roadway’s records. On the basis of the obtained convergence results, the impact of a single fault and the entire fault zone on the roadway stability has been determined. The impact of a single, low throw fault results in a 30% higher vertical convergence than in the case of roadways free of geological disturbance. In the roadway section located in the fault zone, vertical convergence is 4 times higher than in the case of sections free of disturbance impact. The floor heaving constitutes ca. 90% of vertical convergence both for roadway sections situated within the faulted zones and for sections free of the influence of any additional factors.

Classification of Surrounding Rock of Bolt Supported in Coal Mine Roadway

2014 ◽  
Vol 986-987 ◽  
pp. 775-778 ◽  
Author(s):  
Feng Shan Han ◽  
Li Song
Keyword(s):  
Coal Mine ◽  
Classification System ◽  
Knowledge Engineering ◽  
Surrounding Rock ◽  
Rock Classification ◽  
Coal Roadway ◽  
Mine Roadway ◽  
Important Significance ◽  
Bolt Support

Classification of Surrounding rock of roadway of Coal mine bolt supporting is the basis of bolting design, To scientifically design coal roadway bolting, classification of surrounding rock of coal roadway bolting must first be carry out. in this paper, the comprehensive application of knowledge engineering, rock mechanics, we developed the surrounding rock classification system for the bolt support of coal mine roadway engineering, the surrounding rock classification system is practical easy to use, the bolt supporting of roadway surrounding rock classification results to the coal mine roadway bolt support has important significance and practical value.

Dietary Vitamin and Stability of Oral Anticoagulation: Proposal of a Diet with Constant Vitamin K1 Content

1997 ◽  
Vol 77 (03) ◽  
pp. 504-509 ◽  
Author(s):  
Sarah L Booth ◽  
Jacqueline M Charnley ◽  
James A Sadowski ◽  
Edward Saltzman ◽  
Edwin G Bovill ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Vitamin K ◽  
High Performance ◽  
Case Reports ◽  
Food Composition ◽  
Dietary Guidelines ◽  
Dietary Vitamin ◽  
Vitamin K1 ◽  
The Stability ◽  
The Impact

SummaryCase reports cited in Medline or Biological Abstracts (1966-1996) were reviewed to evaluate the impact of vitamin K1 dietary intake on the stability of anticoagulant control in patients using coumarin derivatives. Reported nutrient-drug interactions cannot always be explained by the vitamin K1 content of the food items. However, metabolic data indicate that a consistent dietary intake of vitamin K is important to attain a daily equilibrium in vitamin K status. We report a diet that provides a stable intake of vitamin K1, equivalent to the current U.S. Recommended Dietary Allowance, using food composition data derived from high-performance liquid chromatography. Inconsistencies in the published literature indicate that prospective clinical studies should be undertaken to clarify the putative dietary vitamin K1-coumarin interaction. The dietary guidelines reported here may be used in such studies.

IMPACT OF GOVERNMENT DEBT ON FINANCIAL SECURITY OF UKRAINE

2017 ◽  
Author(s):  
Olena Pikaliuk ◽  
◽  
Dmitry Kovalenko ◽  
Keyword(s):  
Economic Development ◽  
Public Debt ◽  
Positive Impact ◽  
The State ◽  
Financial Security ◽  
State Budget ◽  
The Public ◽  
Debt Security ◽  
The Stability ◽  
The Impact

One of the main criteria for economic development is the size of the public debt and its dynamics. The article considers the impact of public debt on the financial security of Ukraine. The views of scientists on the essence of public debt and financial security of the state are substantiated. An analysis of the dynamics and structure of public debt of Ukraine for 2014-2019. It is proved that one of the main criteria for economic development is the size of public debt and its dynamics. State budget deficit, attracting and using loans to cover it have led to the formation and significant growth of public debt in Ukraine. The volume of public debt indicates an increase in the debt security of the state, which is a component of financial security. Therefore, the issue of the impact of public debt on the financial security of Ukraine is becoming increasingly relevant. The constant growth and large amounts of debt make it necessary to study it, which will have a positive impact on economic processes that will ensure the stability of the financial system and enhance its security.

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