scholarly journals A Nonlinear Creep Model of Rock Salt and Its Numerical Implement in FLAC3D

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xinrong Liu ◽  
Xin Yang ◽  
Junbao Wang
Keyword(s):  
Numerical Simulation ◽  
Rock Salt ◽  
Creep Model ◽  
Secondary Development ◽  
Nonlinear Creep ◽  
Creep Properties ◽  
Long Term Stability ◽  
Creep Characteristics ◽  
Salt Creep

Creep characteristics are integral mechanical properties of rock salt and are related to both long-term stability and security of rock salt repository. Rock salt creep properties are studied in this paper through employing combined methods of theoretical analysis and numerical simulation with a nonlinear creep model and the secondary development in FLAC3Dsoftware. A numerical simulation of multistage loading creep was developed with the model and resulting calculations were found consequently to coincide with previously tested data.

scholarly journals Creep Behaviours of Argillaceous Sandstone: An Experimental and Modelling Study

2020 ◽  
Vol 10 (21) ◽  
pp. 7602
Author(s):  
Huaiguo Zheng ◽  
Qingxiang Cai ◽  
Wei Zhou ◽  
Xiang Lu ◽  
Ming Li ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Creep Model ◽  
Nonlinear Creep ◽  
Underground Excavations ◽  
Creep Theory ◽  
Term Stability ◽  
Long Term Stability ◽  
Rock Creep ◽  
Confining Pressures

Understanding the creep behaviours of rocks is essential for the long-term stability of underground excavations in mining engineering. Creep behaviours are more important when the mining depth is greater, which leads to the emergence of weak rock masses and high in situ stresses. In this study, the creep behaviours of argillaceous sandstone (AS) were systematically investigated. For the experimental investigation, creep tests were conducted on AS with different confining pressures (3, 6, 9, 12, 15, and 18 MPa) using an MTS815.02 rock mechanics test system. The mechanical characteristics of AS were analysed. For the numerical study, a nonlinear creep model of AS under equal and different confining pressures was established based on rock creep theory and plastic theory. The results showed that confining pressure could effectively improve the creep failure strength of AS, accelerating its creep deformation rate and process and reducing the final expansion volume. The nonlinear creep model was embedded in the FLAC3D software, and the experimental and numerical results agreed well. The experimental investigation and proposed creep model can provide important guidance in underground mines for safe long-term stability of underground excavations.

scholarly journals Experimental and Analytical Study on Creep Characteristics of Box Section Bamboo-Steel Composite Columns under Long-Term Loading

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 983
Author(s):  
Shixu Wu ◽  
Keting Tong ◽  
Jianmin Wang ◽  
Yushun Li
Keyword(s):  
Load Level ◽  
Experimental Results ◽  
Creep Model ◽  
Composite Column ◽  
Composite Columns ◽  
Creep Coefficient ◽  
Creep Characteristics ◽  
Section Size ◽  
Steel Composite

To expand the application of bamboo as a building material, a new type of box section composite column that combined bamboo and steel was considered in this paper. The creep characteristics of eight bamboo-steel composite columns with different parameters were tested to evaluate the effects of load level, section size and interface type under long-term loading. Then, the deformation development of the composite column under long-term loading was observed and analyzed. In addition, the creep-time relationship curve and the creep coefficient were created. Furthermore, the creep model of the composite column was proposed based on the relationship between the creep of the composite column and the creep of bamboo, and the calculated value of creep was compared with the experimental value. The experimental results showed that the creep development of the composite column was fast at first, and then became stable after about 90 days. The creep characteristics were mainly affected by long-term load level and section size. The creep coefficient was between 0.160 and 0.190. Moreover, the creep model proposed in this paper was applicable to predict the creep development of bamboo-steel composite columns. The calculation results were in good agreement with the experimental results.

Analysis of Creep Characteristics of Shallow Mined-Out Areas Roof under Low Stress Conditions

2011 ◽  
Vol 105-107 ◽  
pp. 832-836 ◽  
Author(s):  
Shu Ren Wang ◽  
Hui Hui Jia
Keyword(s):  
Creep Deformation ◽  
Thick Plate ◽  
Plate Theory ◽  
Technical Problem ◽  
Stress Conditions ◽  
Creep Model ◽  
Term Strength ◽  
Creep Characteristics ◽  
Over Time

Under low stress conditions, when the load exerting on the mined-out areas roof is less than the rock long-term strength, the rock roof will generate some creep deformation. In order to prevent the roof of the mined-out areas suddenly collapse, and to ensure the operator and construction equipment above the mined-out areas safety, it is an important security technical problem to reveal the creep characteristics of the shallow mined-out areas roof. Taking the mined-out areas of Antaibao Surface Mine as background, considering the rheological properties of rock roof, and assuming the roof was a rectangular thick plate, the creep characteristics of mined-out areas roof were analysed by applying the thick plate theory and Kelvin creep model. The regression equation of the roof deflection increment over time was given, and the creep characteristics of the shallow mined-out areas roof were revealed also.

Creep Characteristics Analysis of Oil Shale and its Application

2010 ◽  
Vol 29-32 ◽  
pp. 2614-2619 ◽  
Author(s):  
Jun Guang Wang ◽  
Bing Liang
Keyword(s):  
Oil Shale ◽  
Stability Control ◽  
Creep Model ◽  
Test Results ◽  
Creep Properties ◽  
Creep Stage ◽  
Creep Characteristics ◽  
Roadway Stability ◽  
Theoretical Significance ◽  
Characteristics Analysis

to study oil shale creep properties, we use rock SJ-1B three-axis creep instrument on oil shale to carry three axis creep test. Through test results, the creep of oil shale is nonlinear, and in accelerating creep stage oil shale injury increased dramatically. Using Burgers creep model introduced damage variable to analyse the oil shale surrounding stress and displacement field and Systematically analyse the creep properties under various support intensity. So it has important theoretical significance and value for the oil shale resource development and roadway stability control.

scholarly journals Nonlinear Creep Model of Deep Gangue Backfilling Material and Time-Dependent Characteristics of Roof Deformation in Backfilling Mining

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Peng Huang ◽  
Jixiong Zhang ◽  
Qi Zhang ◽  
Ntigurirwa Jean Damascene ◽  
Yuming Guo
Keyword(s):  
Large Scale ◽  
High Stress ◽  
Viscoelastic Model ◽  
Creep Model ◽  
Mine Pressure ◽  
Nonlinear Creep ◽  
Viscoelastic Foundation ◽  
The Impact ◽  
Roof Deformation

With the gradual increase in mining depth of coal resource exploitation, deep backfilling mining has effectively solved the impact of strong deep mine pressure and strong mining disturbances. However, after deep backfilling mining, the backfilling material is subjected to high stress for a long time, and its viscoelasticity has a significant impact on the roof control effect. This paper uses a large-scale bulk confinement test device to analyze the viscoelastic properties of gangue, establishes a high-precision fractional viscoelastic creep model, and identifies the gangue parameters. The established fractional viscoelastic model was used as the foundation model of the beam, and the roof model based on the fractional viscoelastic foundation was solved. The top deformation characteristics of elastic foundation and fractional foundation were compared and analyzed, and the time effect, viscoelastic effect, and order effect of the fractional order viscoelastic foundation beam were discussed. The results show that the viscosity of gangue increased under the action of deep high stress. As time increased, the roof deformation also increased. In order to more effectively control the long-term deformation of the roof, the viscosity coefficient of the backfilling material should be greater than 20 MPa. This research provides relevant guidance for the requirements of backfilling materials for deep backfilling mining and the prediction of long-term dynamic deformation of the roof in underground excavations.

Variable Parameters-Based Damage Creep Model of Weak Rock Layer and its Engineering Application

2014 ◽  
Vol 607 ◽  
pp. 835-838
Author(s):  
Wen Dong Yang ◽  
Jin Ping Chen ◽  
Feng Sun ◽  
Yan Mei Zhang
Keyword(s):  
Engineering Application ◽  
Creep Model ◽  
Dam Foundation ◽  
Weak Layer ◽  
Long Term Stability ◽  
Deterioration Effect ◽  
Loading Tests ◽  
Generalized Kelvin Model ◽  
Rock Parameters

In order to study the deformation mechanism of the weak layer in diabase dikes under long-term loading at a hydropower dam foundation, in situ plate loading tests were performed. A damage creep model which improved the five-parameter generalized Kelvin model was established to describe the creep behavior of the weak layer. In this model, the deterioration effect of the rock parameters is considered and the creep parameters of the rock deteriorate gradually. This model is applied in a slope design for a dam foundation at a hydropower station. Long-term stability of the slope after excavation is evaluated. It shows that when damage creep is considered, the displacement is larger compared with the case of ignoring damage creep. The study shows that the deterioration effect of the rock parameters is of full importance for the project design and construction safety.

Long-Term Reliability of Historical Monuments Built with Low Quality Sandstone

2010 ◽  
Vol 133-134 ◽  
pp. 331-336 ◽  
Author(s):  
Els Verstrynge ◽  
Luc Schueremans ◽  
Dionys Van Gemert ◽  
Evert Bourel
Keyword(s):  
Compressive Strength ◽  
Creep Model ◽  
Original Material ◽  
Dead Load ◽  
Test Program ◽  
Long Term Stability ◽  
Sustained Loading ◽  
Historical Monuments ◽  
Set Up

The presented research concerns the long-term stability of a series of historical monuments, which were constructed with low-strength, ferrous sandstone. The main issues are the overall low compressive strength of the sandstone, the large scatter on these strength values, the sensitivity of its characteristics to water absorption and the lack of new original sandstone to replace the damaged zones. The sandstone reacts poorly under sustained high load levels, a situation which typically occurs at the base of bell towers and medieval city towers, as the dead load is considerably high compared to the compressive strength of the sandstone material. To assess the long-term behaviour of the sandstone, a test program has been set up to obtain information on its strength characteristics under monotonic and sustained loading. Therefore, test specimens were taken from the original material of a collapsed church tower. The results of these laboratory tests were used to adapt the parameters of an existing creep model to simulate the long-term behaviour of the sandstone under specific stress levels. Additionally, a number of strengthening solutions are discussed.

scholarly journals Simulation Analysis of the Long-Term Stability for Frozen Soil Roadbed

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Xiaohui Liu ◽  
Jianqing Jia ◽  
Yibo Zhang
Keyword(s):  
Numerical Simulation ◽  
Global Warming ◽  
Tibetan Plateau ◽  
Simulation Analysis ◽  
Frozen Soil ◽  
Temperature Fields ◽  
Term Stability ◽  
Long Term Stability ◽  
Horizontal Displacements

The global warming will lead to rising temperature in Tibetan plateau which will cause some trouble to the long-term stability of frozen soil roadbed. Of course, the temperature is the most important to stability analysis and study of frozen soil roadbed. In this paper, taking the frozen soil roadbed in Tibetan plateau as an example, the numerical simulation model is established. Firstly, the characteristics of temperature fields of frozen soil roadbed in the future 50 years are analyzed, and then the vertical and horizontal displacements without load and under dynamic load are analyzed.

Numerical Simulation Study on Setting Stopping Line of Working Face in Shuguang Mine

2014 ◽  
Vol 580-583 ◽  
pp. 2554-2557
Author(s):  
Hua Jun Xue ◽  
Jun Chen ◽  
Bo Liu ◽  
Jie Kong ◽  
Zhi Jun Hao
Keyword(s):  
Numerical Simulation ◽  
Recovery Rate ◽  
Coal Pillar ◽  
Economic Benefits ◽  
Surrounding Rock ◽  
Long Term Stability ◽  
Rock Stability ◽  
Working Face ◽  
Stopping Line

The surrounding rock deformation of pedestrian roadway was serious under the influence of the working face. And it has affected the safety and normal use of roadway. To ensure the long-term stability of the pedestrian roadway surrounding rock and increase the coal recovery rate of working face, the paper studied the position of stopping line of 1203 working face by numerical simulation. The results show that setting 115m wide of security coal pillar between 1203 working face and pedestrian roadway that the area of stress concentration near the working face has less effect on the pedestrian roadway could better control the surrounding rock stability of the pedestrian roadway and meet the need of the long-term normal production use. It narrows the width of security coal pillar, increase the coal resources recovery rate and achieve the better economic benefits.

scholarly journals Experimental Study on the Creep Characteristics of Cemented Backfill in a Goaf under Water Pressure

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
JingYu Zhang ◽  
Huafeng Deng ◽  
GuoYong Duan ◽  
LiangPeng Wan ◽  
Zuosen Luo ◽  
...  
Keyword(s):  
Creep Rate ◽  
Creep Strain ◽  
Axial Stress ◽  
Water Pressure ◽  
Steady Creep ◽  
Long Term Stability ◽  
Groundwater Environment ◽  
Creep Characteristics ◽  
North Water

As the groundwater environment changes in a goaf, the creep deformation of the backfill underwater pressure is worthy of attention. This paper takes the undercut goaf filling in the Yuzhou section of the middle route of the South-to-North Water Transfer Project as an example. Grading loading creep testing of the backfill under different water pressures was carried out using equipment developed by our research team. Based on the experimental results, the following key points were observed: (1) under the same axial stress, the creep strain and steady creep rate increase with increasing water pressure. Under the same water pressure, the creep strain and steady creep rate also increase with increasing axial stress. (2) The long-term strength of a backfill sample decreases with increasing water pressure and has a nonlinear relationship with water pressure. (3) The increase in water pressure exacerbates the damage of a backfill sample, which is manifested by the secondary crack propagation at the time of failure. Therefore, the increase in water pressure degrades the mechanical properties of the backfill to some extent. The results of this paper provide a reliable theoretical basis for the long-term stability analysis of goaf filling underwater pressure.

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