scholarly journals Numerical simulation of the temperature fields in the shielding walls of frozen soil with multi-circle-pipe freezing in shaft sinking

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 647-652 ◽  
Author(s):  
Yugui Yang ◽  
Mengke Liao ◽  
Haibing Cai ◽  
Peijian Chen
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Numerical Method ◽  
Frozen Soil ◽  
Temperature Fields ◽  
Freezing Time ◽  
Frozen Soils ◽  
Soil Walls ◽  
Shaft Sinking ◽  
Initial Freezing

In this study, the temperature fields of frozen soil wall were calculated by using numerical method, and were analyzed after the soil was actively frozen with different freezing time. The results showed that the temperature field evolved from the freezing pipes, and then formed into frozen soil cylinders. After a certain freezing duration, the cylinders of frozen soil began to connect, and frozen soil walls started to form. At initial freezing stage, the thickness of frozen soil wall was mainly determined by the freezing pipes of the inner two circles. Then, connections were found to have occurred between the inner and outer frozen soil walls. Finally, the temperature fields of the unfrozen and frozen soils reached a state of stability. The results also showed that it was feasible to use numerical method to simulate the temperature fields of frozen soil walls during shaft sinking process, and potentially provided important references for the design and construction of deep alluvium shaft.

scholarly journals Analysis of moisture and temperature fields coupling process in freezing shaft

2019 ◽  
Vol 23 (3 Part A) ◽  
pp. 1329-1335
Author(s):  
Yugui Yang ◽  
Dawei Lei ◽  
Haibing Cai ◽  
Songhe Wang ◽  
Yanhu Mu
Keyword(s):  
Heat Capacity ◽  
Temperature Field ◽  
Specific Heat ◽  
Temperature Change ◽  
Frozen Soil ◽  
Temperature Fields ◽  
Freezing Time ◽  
Coupling Process ◽  
Evolution Characteristics ◽  
Initial Freezing

The temperature change of frozen soil wall and the evolution characteristics of the specific heat capacity are analyzed. The frozen soil cylinders form surrounding freezing pipes at initial freezing stage, and the temperature field of frozen soil presents a non-linear decrease. With the increase of freezing time, the radius of the frozen soil cylinder increases and a frozen soil wall is enclosed. After freezing 30 days, the thickness of the frozen soil wall is obtained as 1.7 m. After freezing 250 days, the thickness of frozen soil wall increases to about 11.0 m.

Determining the efficiency of functioning of systems of temperature stabilization of soils with horizontal evaporator filled with different refrigerants

2019 ◽  
Vol 5 (4) ◽  
pp. 37-57
Author(s):  
Alexey A. Ishkov ◽  
Anatoly A. Gubarkov ◽  
Gennady V. Anikin
Keyword(s):  
Carbon Dioxide ◽  
Soil Temperature ◽  
Negative Temperature ◽  
Frozen Soil ◽  
Temperature Fields ◽  
Positive Temperature ◽  
Stabilization System ◽  
Temperature Stabilization ◽  
Simultaneous Exposure ◽  
Frozen Soils

The construction of buildings and structures in the zones of distribution of frozen soils follows the principle I. The bearing capacity of frozen soils significantly depends on their value of negative temperature. When thawed, such soils shrink, which negatively affects the objects built on them. To prevent this, temperature stabilization systems for frozen soils are used. Simultaneous accounting of the thermal effect on the frozen soil of an engineering object, as well as the temperature stabilization system of soils, is a difficult task, the accuracy of determining the strength characteristics of the soil will depend on the correctness of its solution. This paper presents calculations of the temperature fields of frozen soils with simultaneous exposure to an object with intense heat (RVS with hot oil) and soil temperature stabilization system of the horizontal natural-acting tubular system (GET) type. The calculations follow the previously developed mathematical model of the temperature stabilization system with a horizontal evaporator. The authors consider the efficiency of the operation of the GET system charged with different refrigerants (ammonia and carbon dioxide) for different geocryological subzones of Western Siberia. Particular attention should be paid to the fact that the soil was initially at a close to positive temperature (−0,1 °C), but after calculating for 10 years, the entire soil mass around the evaporation part of the temperature stabilization system froze because of the soil temperature stabilization system. Systems charged with carbon dioxide showed better work efficiency. This is due to two factors: a lower value of the lower critical heat load, which gives more working days per year relative to the system charged with ammonia; and the evaporative part of the system on carbon dioxide, which has the average temperature 1 °C lower than ammonia systems. The results show that carbon dioxide as the heat carrier for the GET system is the most effective.

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.

The Analysis of Temperature and Displacement Coupling in Freeze-Thaw Process of Soil

2011 ◽  
Vol 97-98 ◽  
pp. 192-198
Author(s):  
Shu Guang Hou
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Numerical Computation ◽  
Geometric Model ◽  
Simulation Method ◽  
Frozen Soil ◽  
Displacement Fields ◽  
Soil Frost ◽  
Freeze Thaw ◽  
Thaw Settlement

Through the coupling analysis of temperature and displacement fields in freeze-thaw process of soil by ABAQUS software, a numerical simulation method of the two fields coupling in freeze-thaw process of soil is put forward. In computation, the temperature field is analyzed firstly, and then the physico-mechanical parameters are defined as functions of temperature field. The geometric model and boundary conditions of numerical simulation are identical with these in laboratorial tests. By comparing the computation results of soil freeze-thaw process with its laboratorial test results, it was found that on the curve of soil freeze-thaw process obtained from laboratorial tests there is a short frost-swelling phenomenon at the initial stage of freeze-thaw process, and then is continuous thaw condition, but on the numerical computation curve, the reflect of soil frost swelling stage isn’t obvious. With the exception of this the numerical computation result and laboratorial test result are more identical. The frost-swelling quantum is very small, so the main expression of overall deformation of soil is thaw-settlement deformation. Therefore the frost swelling phenomenon doesn’t influence the end quantum of settlement. For this reason, the computing method introduced in this paper can be used to conduct numerical simulation of the thaw-settlement of frozen soil and to a certain extent guide the designs of subgrade and pavement in permafrost zones.

Numerical Simulation Analysis of Temperature Field on Tympanites Roadbed

2013 ◽  
Vol 838-841 ◽  
pp. 1291-1294
Author(s):  
Jian Yi Yuan ◽  
Chun Feng Wang ◽  
Jian Hua Cheng ◽  
Ding Bang Zhang ◽  
Zhen Hua Wu
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Physical Model ◽  
Simulation Analysis ◽  
Frozen Soil ◽  
Permafrost Region ◽  
Key Points ◽  
Calculating Model

The physical model and calculating model of temperature field are founded according to the founded controlling equation. By simulating the changing progress of climate features, the temperature field of roadbed in permafrost region in different season was obtained. And some results are got by analyzing the diversity of temperature of key points. The last, the technology assumption of effectively controlling tympanites which combines replacing part frozen soil and resisting highway tympanites structure is brought up.

The Characteristics of Temperature Field in the Cup-Shaped Frozen Soil Walls for Horizontal Reinforcement of Shield Tunneling

2014 ◽  
Vol 638-640 ◽  
pp. 870-874
Author(s):  
Jiang Tao Xia ◽  
Li Li Wang ◽  
Ze Jun Liu ◽  
Hua Rong Shen ◽  
Shao Fei Zhang
Keyword(s):  
Growth Rate ◽  
Temperature Field ◽  
Frozen Soil ◽  
Shield Tunneling ◽  
Average Growth Rate ◽  
Average Growth ◽  
Whole Process ◽  
Soil Walls ◽  
Development Characteristic ◽  
The One

The variation of temperature distribution in the cup-shaped frozen soil wall is real-timely monitored during the whole process of the horizontal freezing reinforcement project in Yixian Bridge Station, the first phase in Line 2 of Nanjing Subway. The development characteristic of the temperature field at different depth is analyzed, and the formation time and developing speed of the frozen soil wall is further calculated. The monitoring results show that, the average growth rate of the temperature field at the interface between the frozen soil and the underground continuous wall is significantly faster than the one in the cylinder reinforced area.There is significant differences in the average growth rate of temperature field in the frozen soil wall at different area of the reinforcing plates.

scholarly journals Numerical simulation and measurement analysis of the temperature field of artificial freezing shaft sinking in Cretaceous strata

AIP Advances ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 025209 ◽  
Author(s):  
Zhishu Yao ◽  
Haibing Cai ◽  
Weipei Xue ◽  
Xiaojian Wang ◽  
Zongjin Wang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Measurement Analysis ◽  
Shaft Sinking ◽  
Artificial Freezing

Numerical Simulation of Temperature Field in Laser Remanufacturing

2014 ◽  
Vol 633-634 ◽  
pp. 845-849
Author(s):  
Ling Dong ◽  
Xi Chen Yang ◽  
Yun Shan Wang ◽  
Jian Bo Lei
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Temperature Field ◽  
Theoretical Model ◽  
Temperature Distribution ◽  
Simulation Method ◽  
Temperature Fields ◽  
Simulation Results

It plays an important role in guiding laser remanufacturing process and process control to research temperature field of laser remanufacturing. A numerical simulation method of temperature field based on MATLAB PDE Tool is proposed. Theoretical model of temperature field is presented. The temperature fields at different times are calculated and simulated with finite element method and MATLAB software with PDE Toolbox. The results show that this method can accurately calculate the temperature distribution of the laser remanufacturing process. The simulation results are helpful to optimize process parameters and to improve the quality of laser remanufacturing.

Melting of ice in a porous medium saturated with ice and gas while injecting warm water

2019 ◽  
Vol 13 (4) ◽  
pp. 112-117 ◽  
Author(s):  
V.Sh. Shagapov ◽  
M.N. Zapivakhina
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Low Temperature ◽  
Numerical Models ◽  
Warm Water ◽  
Temperature Fields ◽  
Initial State ◽  
Simplified Models ◽  
Frozen Soils ◽  
Porous Formation

The numerical models for the injection of warm water (in the temperature range from 300 to 340 K) into a cold porous formation are considered. Simplified models describing the processes of heat and mass transfer are proposed. The influence of the parameters determining the initial state of the porous medium, the boundary pressure, temperature and moisture content on the rate of propagation of hydrodynamic and temperature fields in the porous medium is investigated. It has been established that it is economically feasible to melt frozen soils saturated with ice and gas (air) at a sufficiently low temperature of the injected water (about 300 K).

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