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.

Study on Nonlinear Viscoelasto-Plastic Creep Model of Deep Soft Rock

2012 ◽  
Vol 430-432 ◽  
pp. 168-172 ◽  
Author(s):  
Yan Chun Wang ◽  
Yong Yan Wang
Keyword(s):  
Least Squares Method ◽  
Soft Rock ◽  
Creep Model ◽  
Nonlinear Creep ◽  
Test Results ◽  
Mechanical Behaviors ◽  
Exponential Equation ◽  
Creep Stage ◽  
Three Stages ◽  
Plastic Creep

Based on the mechanical behaviors of deep soft rock at the accelerating creep stage, a nonlinear rheological cell containing exponential equation replaces classic linear cell, a new nonlinear viscoelasto-plastic creep model of deep soft rock is established on the basis of Nishihara model, and the model can describe the three stages of rock nonlinear creep. Using the least squares method of Matlab to investigate test results, the result shows the new nonlinear creep model accords better with the creep test curves, and verify correctness of the new model.

scholarly journals A Study on the Creep Characteristics of Airport Viscous Subsoil Based on Unsaturated Stress Level

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jun Feng ◽  
Yue Ma ◽  
Zaobao Liu
Keyword(s):  
Stress Level ◽  
Unsaturated Soil ◽  
Three Dimensional ◽  
Matric Suction ◽  
Creep Model ◽  
Creep Stage ◽  
One Dimensional ◽  
Creep Characteristics ◽  
Stress Levels ◽  
The One

The present study takes the ratio of the matric suction to the net vertical stress and the ratio of the matric suction to the net mean stress as new unsaturated stress levels f and F , respectively. Based on the laboratory tests and theoretical derivation, the modified one-dimensional Mesri creep model and three-dimensional creep model were established, which takes the unsaturated stress level into account. Then, the one-dimensional and three-dimensional creep characteristics of the unsaturated viscous subsoil of an airport under different unsaturated stress levels were analyzed. The following conclusions could be drawn: (1) under different stress levels, the one-dimensional creep deformation of unsaturated soil has a power function relationship with time, and the change rate exponentially decreases with the stress level, which can be well-expressed by the proposed modified one-dimensional Mesri creep model; (2) under different stress levels, the three-dimensional creep strain of the unsaturated soil shows a hyperbolic curve with time and a near-linear relationship at the semilogarithmic coordinate, which can be well-expressed by the proposed modified three-dimensional creep model; (3) under different stress levels, both the one-dimensional creep and three-dimensional creep of the unsaturated soil can be divided into two stages, which are the accelerated creep stage and stable creep stage.

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 Experimental investigation on creep behavior of clastic rock

2020 ◽  
Vol 165 ◽  
pp. 03051
Author(s):  
Zhang Yu ◽  
Zhang Yan ◽  
Mei Song-hua
Keyword(s):  
Axial Strain ◽  
Triaxial Compression ◽  
Testing Machine ◽  
Creep Model ◽  
Test Results ◽  
Creep Failure ◽  
Creep Properties ◽  
Clastic Rock ◽  
Confining Pressures ◽  
The Relationship

Many deflected fault zones exist under the dam foundation Xiang-jiaba Hydropower Station in southwestern China. Clastic rock is the main medium with poor physical and mechanical properties. In or-der to study the creep properties of the clastic rock, triaxial compression creep experiments were carried out on a rock servo-controlling rheology testing machine. From the test results, it can be concluded that the clastic rock has obvious creep characteristics, and the time-dependent deformation is large. Based on the test results, the relationship between axial strain and time under different confining pressures is studied. The relationship between axial strain rates and deviatoric stress under different stress levels is also discussed in de-tail. Furthermore, the creep failure mechanism under different confining pressures is analyzed as well. Therefore, the creep law of the clastic rock specimen is gained. The relationship between the Burgers creep model and its parameters is obtained by fitting the creep curve with Burgers creep model. The result shows that Burgers model can accurately describe the creep properties of the clastic rock in Xiang-jiaba Hydro-power Project.

Failure Reasons and Support Countermeasure of Intersecting Roadwayss in Deep Soft Rock

2013 ◽  
Vol 275-277 ◽  
pp. 2740-2743
Author(s):  
Jing You Yin ◽  
Er Qiang Li ◽  
Jia Wei Liu
Keyword(s):  
Soft Rock ◽  
Stability Control ◽  
Impact Factors ◽  
Underground Engineering ◽  
Deformation And Failure ◽  
Engineering Construction ◽  
Roadway Stability ◽  
Characteristics Analysis ◽  
Soft Rock Roadway ◽  
The Impact

In mining engineering construction, more and more involved in deep soft rock roadway stability control problem, also encountered deep soft rock underground engineering intersection problem, but its classification and support measures are far from perfect and systematic. This paper begins with a brief deep soft rock mine intersection classification, then summarize the deformation and failure characteristics, analysis of the impact factors and the reasons of its destruction, for roadway intersection supporting method is recommended.

Modelling and Data Interpretation of Small Punch Creep Testing

2011 ◽  
Author(s):  
R. Li ◽  
T. H. Hyde ◽  
W. Sun ◽  
B. Dogan
Keyword(s):  
Large Deformation ◽  
Test Data ◽  
Creep Test ◽  
Creep Model ◽  
Test Results ◽  
Creep Tests ◽  
Creep Properties ◽  
Small Punch ◽  
Draft Code ◽  
Uniaxial Creep

The small punch testing (SPT) technique has been proposed for use in determining the creep properties of materials for which only a very small volume of material is available. A draft code of practice on SPT has been produced. However it is not, as yet, generally accepted that the data obtained from small punch tests can be directly related to those which would be obtained from conventional uniaxial creep tests. For this reason, the development of techniques suitable for the interpretation of SPT data has become very important. In this paper, a set of uniaxial creep test data has been characterised in such a way as to gain an improved understanding of the correlation between the data from small punch tests and corresponding uniaxial creep tests. Finite element (FE) analyses of small punch creep tests, using a damage mechanics based creep model, have been performed. The effect of large deformation on the determination of material properties for a creep damage model, has been investigated to take into account the large deformation nature of small punch tests. An equivalent stress, σeq, proposed by the draft code, was used to relate the SPT results to the corresponding uniaxial creep test results. A preliminary assessment of the use of small punch test results, in determining creep properties, has been presented, which includes comparisons of the failure life and equivalent minimum strain rate results obtained from SPTs with the corresponding uniaxial creep test data. Future work related to the interpretation of SPT is briefly addressed.

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.

scholarly journals Experimental Study on the Creep Characteristics of Coal Measures Sandstone under Seepage Action

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 110 ◽  
Author(s):  
Ziheng Sha ◽  
Hai Pu ◽  
Ming Li ◽  
Lili Cao ◽  
Ding Liu ◽  
...  
Keyword(s):  
Creep Deformation ◽  
Deformation Rate ◽  
Confining Pressure ◽  
Test System ◽  
Stability Control ◽  
Surrounding Rock ◽  
Natural State ◽  
Saturation State ◽  
Creep Characteristics ◽  
Coal Measures

The seepage action of underground water accelerates the deformation of roadway surrounding rock in deep mines. Therefore, the study of creep characteristics of surrounding rock under seepage action is the basis for the stability control of roadway surrounding rock in deep water-rich areas. In this paper, a seepage-creep coupling test system for complete rock samples was established. Combined with a scanning electron microscopy (SEM) test system, the seepage-creep law of coal measures sandstone and the damage mechanism were revealed. The study results showed that the maximum creep deformation of sandstone under natural and saturation state decreased gradually with the increase of confining pressure, and the maximum creep deformation under saturation state was greater than the corresponding value under natural state when the confining pressure was same. When the confining pressure was constant, the creep deformation, the constant creep deformation rate and the accelerated creep deformation rate of sandstone increased rapidly with the increase of infiltration pressure. With the change of time, the change of permeability parameters went through three cycles; each cycle was divided into two stages, slow change stage and rapid change stage, and the rate of variation increased with the increase of the seepage pressure. Based on the macroscopic and microscopic characteristics of sandstone rupture, the connection between macroscopic and microscopic mechanism on sandstone rupture was established. The results in this paper can provide a theoretical basis for stability control of roadway surrounding rock in water-rich areas.

scholarly journals Experimental Research on Creep Characteristics of Nansha Soft Soil

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Qingzi Luo ◽  
Xiaoping Chen
Keyword(s):  
Pearl River Delta ◽  
Soft Soil ◽  
Creep Damage ◽  
Pearl River ◽  
Test Results ◽  
Creep Failure ◽  
Consolidation Pressure ◽  
Creep Characteristics ◽  
Triaxial Creep ◽  
Shear Box

A series of tests were performed to investigate the creep characteristics of soil in interactive marine and terrestrial deposit of Pearl River Delta. The secondary consolidation test results show that the influence of consolidation pressure on coefficient of secondary consolidation is conditional, which is decided by the consolidation state. The ratio of coefficient of secondary consolidation and coefficient of compressibilityCa/Ccis almost a constant, and the value is 0.03. In the shear-box test, the direct sheer creep failure of soil is mainly controlled by shear stress rather than the accumulation of shear strain. The triaxial creep features are closely associated with the drainage conditions, and consolidation can weaken the effect of creep. When the soft soil has triaxial creep damage, the strain rate will increase sharply.

Temporary-Creep and Postcreep Properties of Aquaculture Netting Materials With UHMWPE Fibers

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Heidi Moe-Føre ◽  
Per Christian Endresen ◽  
Østen Jensen
Keyword(s):  
Creep Strain ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Tensile Tests ◽  
Test Results ◽  
Elongation At Break ◽  
Creep Properties ◽  
Mean Values ◽  
Ultrahigh Molecular Weight ◽  
Polyester Fibers ◽  
Uhmwpe Fibers

This paper presents test results on temporary-creep properties, recovery of strain postcreep and postcreep tensile properties of a Raschel knitted netting material with a combination of ultrahigh molecular weight polyethylene (UHMWPE) and polyester fibers. Specimens of the material were subjected to uniaxial loading over a period of 30 mins, at a constant creep target load of 10–90% of average tensile strength. The specimens were wet and tested in room temperature. The netting structure experienced creep strain with mean values in the range of 1.3–4.5%, increasing with increased creep target load. In addition, the netting experienced 2% creep strain during on-loading. The creep strains were elastic, while large proportions of the elongation accumulated during on-loading (structural strain of 8.8–27.8%) were long lasting and possibly permanent. Tensile tests showed that for the highest creep target load, strength, and elongation at break increased by 17%.

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