Numerical Simulation on Deformation Features and Filling Efficiency of Channel Goaf Foundation

2013 ◽  
Vol 353-356 ◽  
pp. 3707-3712
Author(s):  
Zhi Dong Zhou ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Hong Ya Yue
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Comprehensive Analysis ◽  
Obvious Effect ◽  
Before And After ◽  
Check Gate ◽  
Deformation Features ◽  
Natural Foundation ◽  
The Stability

For analyzing and evaluating the deformation features of channel goaf foundation and its effect on superstructure, according to the foundation reinforcement engineering of Ji-Liang Channel Check Gate, the comparative analysis on the differential settlement between the unfavorable foundation and natural foundation was performed by numerical simulation with FLAC3D. The computer results showed that the present foundation had obvious effect on the stability and security of the superstructure, so the engineering treatment are needed. Based on technical-economic comprehensive analysis among three treatment methods for strengthening the channel golf foundation with different kinds of filling, the reasonable method is put forward in this paper. By comparing mechanical characteristic of flashboard in channel goaf before and after strengthening, we confirmed the foundation stability of channel goaf and the security of the ground building which can satisfy the long term usage requirements.

Study on the Capacity Increasing and Dam Heighten of Plain Reservoirs

2013 ◽  
Vol 353-356 ◽  
pp. 2531-2536
Author(s):  
Xiu Guang Song ◽  
Zhi Dong Zhou ◽  
Hong Bo Zhang ◽  
Hong Ya Yue
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Site Investigation ◽  
Seepage Flow ◽  
Differential Settlement ◽  
Construction Technology ◽  
Dam Stability ◽  
The Stability ◽  
Design Construction

In order to solve the problem of differential settlement, seepage flow and stability between the new and old dam boundary in capacity increasing of the plain reservoirs, the comparative analysis on the stability of the dam slope with different methods on dealing with the new and old dam boundary was performed by numerical simulation with FLAC3D. The result shows that combining the new and old dam by using geogrid indicates superiority for reducing differential settlement, improving the dam stability and safety, etc. In the meantime, on the basis of actual site investigation and theoretical analysis, combined with the requirements of design, construction and management in capacity increasing of the plain reservoirs, the key construction technology was put forward and widely applied foreground, which can improve the quality of the construction, reduce engineering disease and provide references for capacity increasing engineering of in plain reservoirs.

Influence of Long-Term Exposure in the Concrete of FRP Rebars on Bond Characteristics

2017 ◽  
Vol 263 ◽  
pp. 3-6
Author(s):  
Andrey Benin ◽  
Sergey Semenov ◽  
Ekaterina Bogdanova
Keyword(s):  
Comparative Analysis ◽  
Glass Fiber Reinforced Plastic ◽  
Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
Before And After ◽  
One Year ◽  
Bond Glass ◽  
Bond Characteristics

The current experimental research is devoted to comparison of bond glass fiber reinforced plastic with concrete before and after long-term (quarter year, half year and one year) exposure in the concrete on the air and in the water. The comparative analysis of experimental results was performed.

scholarly journals Performance of three iGrav superconducting gravity meters before and after transport to remote monitoring sites

2020 ◽  
Vol 223 (2) ◽  
pp. 959-972
Author(s):  
Florian Schäfer ◽  
Philippe Jousset ◽  
Andreas Güntner ◽  
Kemal Erbas ◽  
Jacques Hinderer ◽  
...  
Keyword(s):  
Geothermal Field ◽  
Absolute Gravity ◽  
Absolute Calibration ◽  
Noise Levels ◽  
Before And After ◽  
Gravity Measurements ◽  
Superconducting Gravity ◽  
The Stability ◽  
Comparison Measurements

SUMMARY High spatial and temporal resolution of gravity observations allows quantifying and understanding mass changes in volcanoes, geothermal or other complex geosystems. For this purpose, accurate gravity meters are required. However, transport of the gravity meters to remote study areas may affect the instrument's performance. In this work, we analyse the continuous measurements of three iGrav superconducting gravity meters (iGrav006, iGrav015 and iGrav032), before and after transport between different monitoring sites. For 4 months, we performed comparison measurements in a gravimetric observatory (J9, Strasbourg) where the three iGravs were subjected to the same environmental conditions. Subsequently, we transported them to Þeistareykir, a remote geothermal field in North Iceland. We examine the stability of three instrumental parameters: the calibration factors, noise levels and drift behaviour. For determining the calibration factor of each instrument, we used three methods: First, we performed relative calibration using side-by-side measurements with an observatory gravity meter (iOSG023) at J9. Secondly, we performed absolute calibration by comparing iGrav data and absolute gravity measurements (FG5#206) at J9 and Þeistareykir. Thirdly, we also developed an alternative method, based on intercomparison between pairs of iGravs to check the stability of relative calibration before and after transport to Iceland. The results show that observed changes of the relative calibration factors by transport were less than or equal to 0.01 per cent. Instrumental noise levels were similar before and after transport, whereas periods of high environmental noise at the Icelandic site limited the stability of the absolute calibration measurements, with uncertainties above 0.64 per cent (6 nm s–2 V–1). The initial transient drift of the iGravs was monotonically decreasing and seemed to be unaffected by transport when the 4K operating temperatures were maintained. However, it turned out that this cold transport (at 4 K) or sensor preparation procedures before transport may cause a change in the long-term quasi-linear drift rates (e.g. iGrav015 and iGrav032) and they had to be determined again after transport by absolute gravity measurements.

The Effect of VikaneTm on the Stability of Cellulosic and Ligneous Materials -- Measurement of Deterioration by Chemical and Physical Methods

1990 ◽  
Vol 185 ◽  
Author(s):  
Helen D. Burgess ◽  
Nancy E. Binnie
Keyword(s):  
Hydrolytic Degradation ◽  
Degree Of Polymerization ◽  
Accelerated Ageing ◽  
Total Acid ◽  
Long Term Stability ◽  
Before And After ◽  
Pulp Fibres ◽  
General Scientific ◽  
The Stability

AbstractVikaneTM (sulphuryl fluoride) is a commercial fumigant[1] which is used for the control of pests in museum collections. This paper summarizes the results obtained through an investigation of the effect of VikaneTM on twenty-five paper and textile samples. Samples chosen were representative of artifacts present in North American collections (cotton, linen, jute, and wood pulp fibres, from 1622 to present).The effect of the fumigation treatment has been evaluated by chemical and physical analyses: (1) Acidity -- surface pH, cold extracted pH, total acid (iodometric titration), (2) Oxidative and Hydrolytic Degradation - viscometric average degree of polymerization, carbonyl content (hydrazone derivatization), (3) and Fumigant Residues (specific ion electrode). Analysis of unfumigated and fumigated samples was carried out before and after accelerated ageing (70°C and 50% relative humidity) in order to estimate the long term stability of fumigated samples.The data obtained show that commercial grade VikaneTM degrades cellulosic and ligneous fibres. A second set of experiments on two fibre types using a new experimental grade of VikaneTM gave significantly less degradation. The presentation of this work will concentrate upon a general scientific interpretation of results.It is anticipated that the conclusions will be applicable to a broad range of artifacts.

scholarly journals Plugging and Its Stability Evaluation for the Ore Pass in the Nonempty Condition Based on Controllable Grouting of Cement-Sodium Silicate Grout

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ye Yuan ◽  
Dengpan Qiao ◽  
Shibo Yu
Keyword(s):  
Rock Mass ◽  
Setting Time ◽  
Stress Monitoring ◽  
Diffusion Distance ◽  
Vertical Diffusion ◽  
Obvious Effect ◽  
The Stability ◽  
Ore Pass ◽  
Loose Rock

Aimed at the problem to plug the main ore pass with the large collapse at Xingshan Iron Mine, the viscosity-time test and the heap perfusion test of cement-silicate grout in a loose rock mass are carried out. The relationship between the vertical diffusion distance of cement-silicate grout and setting time of grout is studied, and research results are applied to the design of plugging engineering of the main ore pass in -330 m. Based on the numerical simulation of the plugging structure and the long-term stress monitoring of the cable sensors, the stability of the plugging structure itself and the control for the movement of shafts nearby are comprehensively evaluated. The test results show that for a specific loose rock mass, the vertical diffusion distance of cement-silicate grout in the loose rock mass is a power function of grout setting time. Based on the design concept to plug the main ore pass with the large collapse using artificially constructed “bite-bonded arch,” the plugging design and construction procedures are proposed. A numerical model and long-term monitoring of cable stress show that the plugging structure is stable and has an obvious effect on the control movement of abutment shafts.

Stability Analysis of Tunnel during the Excavation Based on ANSYS

2014 ◽  
Vol 577 ◽  
pp. 1135-1138
Author(s):  
Bing He ◽  
Guang Zhi Yin
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Stress Condition ◽  
Stability Control ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Rock Stability ◽  
Before And After ◽  
The Stability

This paper combines the geological condition of Miaoziwan tunnel and numerical simulation software ANSYS to analyze the displacement and stress condition of surrounding rock before and after the excavation. Furthermore, the stability of overlying rock in the tunnel was studied based on the displacement and stress condition of surrounding rock. The breaking law of overlying rock was studied considering the influencing factors to the stability of surrounding. The study and analysis to the breaking law of overlying rock can be helpful to the improvement of surrounding rock stability control and supporting system. Moreover, the result can be the guidance to the excavation.

scholarly journals Numerical Simulation and Model of Deformation Features of Destabilized Mining Slope Under Fault-Controlled Conditions

2020 ◽  
Vol 24 (1) ◽  
pp. 61-69
Author(s):  
Yiqing Lv
Keyword(s):  
Numerical Simulation ◽  
Underground Mining ◽  
Research Area ◽  
Shanxi Province ◽  
Future Studies ◽  
Deformation Features ◽  
Tectonic Development ◽  
The Stability ◽  
Coal Measures ◽  
Communication Towers

This paper took the Fengmaoding slope, typically found in the mountainous areas of central Shanxi province, as its research area. The stratum structure of the Fengmaoding slope is a typical coal measures stratum covered by a layer of loess. There are communication towers on the slope mass and top of the slope; railways, roads, and rivers at the foot of the slope. There are many villages across from the slope, therefore, the buildings and structures nearby, even the lives of the villagers are threatened by the damages caused by the deformation of the slope. Tectonic development and mining activities have very profound effects on the stability of the slope. Considering the above, this paper analyzed the effects of the fault in controlling the deformation features of the destabilized slope during underground mining by adopting the method of numerical simulation from these perspectives including displacement, stress, strain, among others. under different circumstances (the faulted and unfaulted) so as to provide guidance for future studies about landslides of the same type and give preventive proposals for reference.

Numerical Simulation Analysis on Stability of Coal Pillar of Empty Mine Goaf in North of Shanxi Province

2013 ◽  
Vol 470 ◽  
pp. 205-210
Author(s):  
Hao Tang ◽  
Zi Guang He ◽  
Hai Bo Lian
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Coal Pillar ◽  
Shanxi Province ◽  
Analysis Model ◽  
Term Stability ◽  
Long Term Stability ◽  
The Law ◽  
The Stability

The analysis model of coal pillar of a empty mine goaf in north of Shanxi province was constructed and the process of coal pillar from formation to weathering was simulated through the application of software of FLAC3D in this article. The stressstrain and the law of plasticity transformation of coal pillar from formation to weathering were analyzed and the long-term stability of coal pillar was forecasted. The result showed that the stability of coal pillar was bad for excessive excavated and weathering and the coal pillar will be broken easier for pressure and shear.

scholarly journals Comparative analysis of change in budget income from the increased VAT rates

2021 ◽  
Vol 12 (1) ◽  
pp. 66-74
Author(s):  
Ekaterina A. Tolmacheva ◽  
Ekaterina S. Podbornova
Keyword(s):  
Comparative Analysis ◽  
Value Added ◽  
Tax System ◽  
Factors Affecting ◽  
Indirect Taxes ◽  
Points Of View ◽  
The Stability ◽  
Additional Income

Indirect taxes play an important role in the Russian tax system, one of which is VAT. Value added tax is one of the most complex taxes in the Russian tax system. The article is devoted to the study of changes in budget income from the increased VAT rate. A comparative analysis of changes in budget income from an increased VAT rate is carried out. The list of basic and special indicators of changes in budget income from the increased VAT rate has been clarified. Particular attention is paid to the facts that have a significant impact on changes in budget income with an increased VAT rate. VAT is capable of ensuring the stability of the entire Russian system of public finance in the long term, not to mention the fact that stability is especially important in a crisis. Therefore, any steps to change the tax, especially in the direction of increasing, should be carefully calculated from all possible points of view, and not only from the side of additional income to the budget. In this regard, the objectives of this study are to determine the significance of factors affecting the quality of VAT administration, to identify the main constraints that reduce the efficiency of VAT collection in the OECD countries and Russia, and to develop recommendations for improving the quality of VAT administration in Russia.

The Application of FLAC Software in Stability Analysis of Highway Slope Reinforced by Prestressed Anchor Cable

2012 ◽  
Vol 241-244 ◽  
pp. 2158-2162
Author(s):  
Hui Min Wang ◽  
Liang Cao ◽  
Ji Yao ◽  
Ze Li
Keyword(s):  
Numerical Simulation ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Stability Factor ◽  
Anchor Cable ◽  
Equilibrium Method ◽  
Before And After ◽  
Calculation Results ◽  
The Stability ◽  
Prestressed Anchor

rigid limit equilibrium method and numerical simulation of FLAC software based on strength reduction method was used in this paper, and the stability of a highway slope before and after the reinforcement by prestressed anchor cable was analyzed. The calculation results showed that, the stability of designed excavated slope could not meet the requirements, while the stability of reinforced sloped by prestressed anchor cable could. The sliding surface of the slope and the corresponding stability factor could be obtained in two ways, but the numerical simulation of FLAC software considered the material deformation, so the calculation results was smaller than the results of rigid limit equilibrium method.

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