scholarly journals Research on the Stability Evaluation Model of Composite Support Pillar in Backfill-Strip Mining

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xiaojun Zhu ◽  
Guangli Guo ◽  
Hui Liu ◽  
Xueni Peng ◽  
Xiaoyu Yang
Keyword(s):  
Evaluation Model ◽  
Limit Equilibrium ◽  
Coal Pillar ◽  
Earth Pressure ◽  
Strip Mining ◽  
Stability Evaluation ◽  
Composite Support ◽  
Filling Materials ◽  
Support Pillar ◽  
The Stability

Backfill-strip mining, which combines the advantages of strip mining and backfill mining, is proposed to overcome high cost and shortage of filling materials in coal mines at present. The composite support pillar (CSP) is a combined support pillar of the filling body and coal pillar for supporting the overlying strata and achieving subsidence control. The stability of CSP is the key to the success of subsidence control in backfill-strip mining engineering. A stability evaluation model of the CSP mechanical model was proposed. First, the lateral stress between the coal pillar and filling body is calculated in consideration of their interaction relation in CSP based on the earth pressure theory. Then, the width calculation models of the broken and plastic zones of three types of CSPs are established on the basis of limit equilibrium theory. On this basis, the mathematical model of the safety design width of the three types of CSPs is proposed to ensure the stability of CSP. Meanwhile, an engineering case of stability width design of CSP is shown. This study can provide theoretical reference and technical support for the engineering design of backfill-strip mining.

scholarly journals Stability Evaluation of an Expressway Construction Site above an Abandoned Coal Mine Based on the Overlay and Index Method

2019 ◽  
Vol 11 (19) ◽  
pp. 5163 ◽  
Author(s):  
Qingbiao Guo ◽  
Guangli Guo ◽  
Yingming Li ◽  
Lei Wang ◽  
Xingwang Zhao
Keyword(s):  
Coal Mine ◽  
Traffic Safety ◽  
Evaluation Model ◽  
Scoring Functions ◽  
Construction Site ◽  
Stability Evaluation ◽  
Index Method ◽  
Expressway Construction ◽  
The Stability ◽  
Abandoned Coal Mine

In recent years, more and more expressways pass through the abandoned coal mine, while the surface residual subsidence of the abandoned coal mine threatens the operation safety of the expressway. It is of significance to evaluate the stability of the construction site and take reasonable managements for effectively guaranteeing the traffic safety. How to accurately evaluate the stability of the construction site is the primary problem. This study proposes a stability evaluation model using the overlay and index method and points out that the evaluation scores and weights of evaluation indices are key parameters to determine the reliability of evaluation results. To reasonably determine the evaluation score, the scoring criteria of qualitative indices is obtained by the equidistant method, while the scoring criteria of quantitative indices is obtained by establishing scoring functions. The weights of evaluation indices are got by adopting the FAHP (fuzzy analytic hierarchy process). Then the built model is applied to evaluate the stability of the Wuyun Expressway construction site, and the results show that the Wuyun Expressway construction site is basic stable. Finally, the sensitivity of indices weights on the evaluation result is analyzed with the maximum C k ( C m , p c ) of 5.9% far lower than the weight change of ±30%, and the average residual subsidence velocity of the maximum subsidence point is 0.0456 mm/d using a high-resolution leveling, proving the credibility of the proposed model. Research results provide new ideas and systematic technical references for the stability evaluation of the construction site above an abandoned coal mine.

The Stability Evaluation of the Landslide in the Northwest Sit of Certain a Substation

2012 ◽  
Vol 170-173 ◽  
pp. 187-190
Author(s):  
Pei Xi Guo
Keyword(s):  
Limit Equilibrium ◽  
Two Dimensional ◽  
Stability Evaluation ◽  
Soil C ◽  
Limit Equilibrium Theory ◽  
Transformer Substation ◽  
Geological Conditions ◽  
Calculation Process ◽  
The Stability ◽  
Investigation Report

The landslide which located in the northwest of the transformer substation was studied and the evaluation of the stability was contained.Through analyzing the regional geological conditions and landslide engineering conditions, summary of the reason of the landslide was made. Based on two-dimensional rigid body limit equilibrium theory, residual thrust method was used in calculation. Through the researching of the landslide, some factors that play important role were found. According to the investigation report, select the main slip profile as the basis for calculating. Combining with soil C&φ, the value of the inversion parameters can be got. Calculation process contained two engineering conditions. In the natural condition, the landslide is stable, and in the rainstorm condition, the landslide is not stable.

Seismic Strengthening Methods and Analysis of Instability of Gravity Retaining Walls

2014 ◽  
Vol 971-973 ◽  
pp. 2141-2146
Author(s):  
Tian Zhong Ma ◽  
Yan Peng Zhu
Keyword(s):  
Safety Factor ◽  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Theoretical Formula ◽  
Seismic Strengthening ◽  
Gravity Retaining Wall ◽  
Overturning Stability ◽  
The Stability

Using the frame supporting structure of pre-stressed anchor bolt seismic strengthening technology reinforced the instability of gravity retaining wall. Earth pressure of retaining wall in seismic reinforcement after shall take between active and static earth pressure for the form of the distribution . In this paper, based on the limit equilibrium theory, and the whole stability for retaining walls is analysis, the theoretical formula of the stability safety factor between stability against slope and overturning safety factor is derived. By calculation and comparative analysis with an example, the stability safety factor of gravity retaining wall with introducing this strengthening technology is improved obviously. Keywords: frame anchor structure; seismic strengthening; anti-slip and anti-overturning; stability coefficient;

Stability Analysis of Tailing Dam under the Action of Seepage

2014 ◽  
Vol 556-562 ◽  
pp. 812-816
Author(s):  
Hui Ying Zhang ◽  
Ai Min Gong ◽  
Hai Yan Huang
Keyword(s):  
Working Conditions ◽  
Limit Equilibrium ◽  
Element Model ◽  
Seepage Flow ◽  
Tailings Dam ◽  
Stability Evaluation ◽  
Seepage Force ◽  
Stability Against Sliding ◽  
Tailing Dam ◽  
The Stability

A finite element model of tailings dam model was used to simulate the steady seepage field and analysis the stability under different working conditions. The head contour, velocity, seepage flow and seepage gradient was analyzed. The stability against sliding in this tailings dam was analyzed with the help of the simplified Bishop method which is based on rigid body limit equilibrium coupled with seepage force. The security coefficient under different working conditions was calculated. The analysis result shows that the safety factor meets the specification requirements, and which provides reference for the stability evaluation of tailings dam.

STABILITY OF WATERFRONT RETAINING WALL SUBJECTED TO PSEUDO-DYNAMIC EARTHQUAKE FORCES AND TSUNAMI

2008 ◽  
Vol 02 (02) ◽  
pp. 107-131 ◽  
Author(s):  
SYED MOHD. AHMAD ◽  
DEEPANKAR CHOUDHURY
Keyword(s):  
Sliding Mode ◽  
Tsunami Wave ◽  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Inertia Force ◽  
Dynamic Approach ◽  
Modes Of Failure ◽  
Mode Of Failure ◽  
The Stability

The paper pertains to a study in which the waterfront retaining wall has been analyzed for its stability when it is exposed to the forces jointly coming from an earthquake and tsunami. Closed form solutions following the simple limit equilibrium principles have been proposed. For the calculation of the seismic passive earth pressure and the wall inertia force, pseudo-dynamic approach has been considered, while the hydrodynamic and the tsunami wave pressures have been calculated using different approximating solutions available in literature. The results presented in the sliding and overturning modes of failure of the wall show that the stability of the wall gets seriously challenged when it gets jointly exposed to the effects of the tsunami and earthquake. About 92% decrease is observed in the value of the factor of safety in sliding mode of failure of the wall as the ratio of tsunami wave height to the upstream still water height increases from 0 to 1.5. Also, the critical mode of failure of the wall has been found to be that of the overturning. Effect of different parameters involved in the analysis has also been studied and it has been observed that quite a few of them like kh, kv, ϕ, δ, ru have a significant effect on the stability of the wall. Comparison with a previously existing methodology using pseudo-static approach suggests that the present pseudo-dynamic approach is more realistic and comparatively less conservative and hence can be used as a handy simple economic method for the design of the waterfront retaining walls exposed to the combined effects of earthquake and tsunami.

scholarly journals Evaluation of Reservoir Slope Stability Considering Friction Angle Uncertainty and Earthquakes

2020 ◽  
Vol 20 (5) ◽  
pp. 273-280
Author(s):  
Seungwon Shin ◽  
Seongnoh Ahn ◽  
Sungsu Lee ◽  
Jongwon Jung
Keyword(s):  
Water Level ◽  
Evaluation Method ◽  
Limit Equilibrium ◽  
Weather Conditions ◽  
Friction Angle ◽  
Soil Strength ◽  
Seismic Events ◽  
Stability Evaluation ◽  
Strength Parameters ◽  
The Stability

Approximately 76% of the reservoirs built in Korea are facilities that are more than 50 years old. The risk of disasters has increased because of reservoir aging and the deepening polarization of drought and floods caused by abnormal weather conditions. In addition, the number of earthquakes has been gradually increasing in Korea, and anxiety has increased significantly because of the recent series of large earthquakes since the earthquakes in Pohang and Gyeongju. Accordingly, risk assessment and preparation are required through the stability evaluation of earthquakes in old reservoirs. The stability evaluation method, based on the limit equilibrium method, depends highly on the soil strength parameters; hence, it is essential to identify the soil strength parameters accurately. However, even though the soil strength parameters are of the same layer, they have different values because of the heterogeneity of the ground. It is difficult to select the representative value of the soil strength parameters because of the time and economic constraints of the ground survey. Therefore, in this study, the probability of failure of an old reservoir owing to seismic events was calculated, and the stability was evaluated. The water level and the uncertainty of the strength constant of the reservoir were considered. The analysis showed that the probability of collapse has increased because of the increase in the water level and the coefficient of variation of the friction angle, and the stability of the reservoir, considering the seismic events, was found to not satisfy the minimum factor of safety for slope activities.

scholarly journals Comparative analysis of stability of large diameter steel cylinder based on FEM and limit equilibrium

2020 ◽  
Vol 198 ◽  
pp. 03026
Author(s):  
Chang-yi Yu ◽  
Ming-yue Lu
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Reduction Method ◽  
Limit Equilibrium ◽  
Large Diameter ◽  
Earth Pressure ◽  
Steel Cylinder ◽  
The Earth ◽  
Analysis Of Stability ◽  
The Stability

The stability mechanism of large-diameter steel cylinder under fill load has not yet formed a complete theory. In order to calculate the stability of the steel cylinder island arm structure in a certain project, the limit equilibrium and finite element method are used in this paper. The limit equilibrium method is based on the limit equilibrium of the soil inside and outside the steel cylinder, taking into account the earth pressure and friction force on the cylinder, and using moment equilibrium to calculate its stability coefficient. Secondly, the finite element strength reduction method is adopted to analyze the stability of the steel cylinder island arm structure by using strength parameters to correlate with the temperature field and changing the boundary conditions of the temperature field. The results and analysis methods of this paper provide references for the construction and design of the same type of projects.

Slope Stability Evaluation by the Improved AHP and Extenics Theory

2013 ◽  
Vol 405-408 ◽  
pp. 106-110 ◽  
Author(s):  
Guo Song Liu ◽  
Chun Ming Qi ◽  
Chun Long Nie ◽  
Jie Hu
Keyword(s):  
Correlation Function ◽  
Slope Stability ◽  
Evaluation Model ◽  
Stability Evaluation ◽  
Analytic Hierarchy ◽  
Judgment Matrix ◽  
The Stability ◽  
Hierarchy Process ◽  
The Relationship ◽  
Element Theory

According to the improved 3 scales (0, 1, 2) Analytic Hierarchy Process (E-AHP) and Extenics theory, an evaluation model is built to evaluate the slope stability. The model takes into account nine indexes that affect the slope stability. The classical matter element and extensional matter elemen are established by collectting actural data. And combined with the specific example, this model accurately calculated the stability state of the slope. The results shown that it not only can take advantage of Extenics Matter-Element theory and the correlation function to study the relationship between index and slope stability, but also can avoid the shortcomings of the traditional AHP judgment matrix inconsistent. It is a new model to evaluate the slope stability.

The Fuzzy Matter-Element Comprehensive Evaluation Model for Erosion Stability of Geocell Protection of Slope and its Application

2012 ◽  
Vol 594-597 ◽  
pp. 2945-2950
Author(s):  
Guang Yue Wang ◽  
Jan Wu Zhao
Keyword(s):  
Index System ◽  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Element Model ◽  
Stability Evaluation ◽  
Correlation Degree ◽  
Comprehensive Evaluation Model ◽  
The Index System ◽  
The Stability ◽  
Matter Element Model

To solve the existing fuzziness in the grading of stability evaluation of geocell protected slope and inconsistent between evaluation result by single index and the fact, this paper establishes index system of the stability evaluation of geocell protection of slope and propose a method. First, two-grade Fuzzy Matter-element Model is established based on the index system. Second, factor weights of evaluation index are calculated by AHP. Finally, the grade of the stability of geocell protection of slope is obtained based on Correlation Degree. Analysis results show that based on comprehensive consideration of subjective factors and objective factors, this method is effective and agrees well with engineering practical.

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