Study on the influence of airflow on the temperature of the surrounding rock in a cold region tunnel and its application to insulation layer design

2014 ◽  
Vol 67 (1-2) ◽  
pp. 320-334 ◽  
Author(s):  
Xianjun Tan ◽  
Weizhong Chen ◽  
Diansen Yang ◽  
Yonghao Dai ◽  
Guojun Wu ◽  
...  
Keyword(s):  
Surrounding Rock ◽  
Insulation Layer ◽  
Cold Region

Numerical Analysis of Optimization Design for Insulation Layer in Cold Regions Tunnel

2014 ◽  
Vol 1065-1069 ◽  
pp. 368-372 ◽  
Author(s):  
He Song ◽  
Chao Liang Ye ◽  
Jun Feng Mi
Keyword(s):  
Optimization Design ◽  
Frost Damage ◽  
Surrounding Rock ◽  
Temperature Fields ◽  
Insulation Layer ◽  
Cold Region ◽  
Element Analysis ◽  
Penetration Length ◽  
Dimensional Finite Element ◽  
Frost Penetration

Setting of insulation layer is widely recognized to prevent frost damage for tunnels constructed in cold region. Optimization design of insulation layers, however, still need deeply investigate. In this paper, taking Houanshan tunnel as example, two-dimensional finite element analysis on the optimization design of insulation layers has been carried out by ABAQUS. The tunnel temperature fields due to various thickness and length of insulation layer are numerically analyzed. It shows that ,1)4.85°C increased at backside of insulation layer with thickness of 5cm, while 5.8°C increased for thickness of 7cm;2) frozen depth of surrounding rock decrease with the increase of insulation layer thickness. The farther distance to tunnel portal, the smaller thickness of insulation layer required to prevent the surrounding rock from freezing;3)According to analysis, frost penetration length should be 450~500m before tunnel holing-through ,while 720m~830m after tunnel holing-through.

Study on the Range of Freeze-Thaw of Surrounding Rock from a Cold-Region Tunnel and the Effects of Insulation Material

2011 ◽  
Vol 399-401 ◽  
pp. 2222-2225 ◽  
Author(s):  
Peng Qi ◽  
Jing Zhang ◽  
Zhi Rong Mei ◽  
Yue Xiu Wu
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Surrounding Rock ◽  
Insulation Material ◽  
The Finite Element Method ◽  
Cold Region ◽  
Coupled Problem ◽  
Fluid Transfer ◽  
Tunnel Depth ◽  
The Relationship

A mathematical models for the coupled problem is established by considering heat and mass transfer and phase change for rock mass at low temperature, according to the theory of heat and mass transfer for porous media. It is considered of the influences of fluid transfer on the heat conduction and the temperature gradient on the seepage. By adopting the finite element method, the numerical simulation is done to study the range of frost-thaw of surrounding rock and the effects of insulation material in cold regions, which analysis the influence of tunnel depth and surrounding rock class on the range of frost-thaw, the change law of the frost-thaw area of different insulation material and the relationship between the frost-thaw area and the thickness of insulation material.

scholarly journals Investigation of the Thermal Performance of Energy Tunnel Equipped with the Insulation Layer Considering Ventilation and Groundwater Seepage

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Guozhu Zhang ◽  
Ziming Cao ◽  
Xu Zhao ◽  
Yongli Xie ◽  
Xiaohua Liu ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Groundwater Flow ◽  
Exchange Rates ◽  
Thermal Performance ◽  
Surrounding Rock ◽  
Interface Temperature ◽  
Insulation Layer ◽  
Groundwater Seepage ◽  
Ground Heat Exchangers ◽  
Reduction Effect

The insulation layer is usually installed in the tunnel structure, whereas the influence of the insulation layer on the thermal behavior of energy tunnel ground heat exchangers (GHEs) is rarely investigated. The model tests were performed in this study to evaluate the heat transfer potential of the energy tunnel with the insulation layer under ventilation and groundwater seepage. The results can be obtained as follows: first, the fluctuations of air temperature and surrounding rock temperature at different locations are relevant to insulation layer, ventilation, and groundwater seepage. Second, the reduction effect of ventilation on the interface temperature of tunnel lining and surrounding rock is alleviated when using an insulation layer, and the interface temperature at upstream section of groundwater seepage is more easily affected by the energy tunnel GHEs. Third, the variation range of ground temperature is wider at the downstream section of groundwater flow. Moreover, the heat exchange rates of tunnel without the insulation layer improve by 5.82% and 6.45% with increasing wind speed at two groundwater flow velocities of 1 × 10 − 4 and 5 × 10 − 4  m/s, and there are only 2.03% and 0.77% enhancements of heat exchange rates by ventilation for the tunnel with the insulation layer. However, the thermal performance of the energy tunnel improved by groundwater is less relevant to the existence of the insulation layer. The relevant findings can provide an effective guidance for the following research and design of the energy tunnel.

Analysis on Coupling of Temperature Field and Stress Field for Tunnel Surrounding Rock in Cold Region

2012 ◽  
Vol 594-597 ◽  
pp. 2578-2581
Author(s):  
Hui Mei Zhang ◽  
Yuan Liang ◽  
Chuan Gao Chen ◽  
Hai Bo Cao
Keyword(s):  
Theoretical Model ◽  
Theoretical Basis ◽  
Mutual Influence ◽  
Surrounding Rock ◽  
Stress Fields ◽  
Cold Region ◽  
Rock Body ◽  
Volume Load ◽  
Engineering Parameters ◽  
Mountain Tunnel

Based on the theory of mass and energy transfer, the coupling theoretical model of temperature and stress fields in the process of rock freeze-thaw was established considering the volume load caused by temperature change within the rock body. Taking Daban mountain tunnel surrounding rock at its exit as example, the heat--stress coupling process was numerically calculated, and the mutual influence and varied laws of temperature and stress fields were researched. The simulating result is similar to the current results and engineering experience, which can verify the correctness of the theoretical model and the reliability of calculation method, and also provide some theoretical basis for determining the engineering parameters scientifically, optimizing the lining and supporting scheme and ensuring the safety of design and construction.

scholarly journals Finite Element Analysis of Surrounding Rock with a Thermal Insulation Layer in a Deep Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hao Wang ◽  
Qianyu Zhou
Keyword(s):  
Finite Element ◽  
Thermal Insulation ◽  
Heat Dissipation ◽  
Heat Insulation ◽  
Surrounding Rock ◽  
Insulation Layer ◽  
Distribution Law ◽  
Element Analysis ◽  
Climate Conditions ◽  
Deep Mine

As the main heat source, surrounding rock heat dissipation is a very important factor in the prediction of mine climate conditions, especially in deep high-temperature mines. To reveal the heat control mechanism of surrounding rocks due to the thermal insulation of deep roadways, a mathematical model of the surrounding rocks around deep roadways with heat insulation was established with the finite element method, and a corresponding calculation program was developed. A series of results were determined to show how setting an insulation layer could affect the distribution law of the temperature field within and around tunnels. Therefore, rules of the variation in wall temperature and temperature gradient with thermal conductivity coefficients were obtained within and around tunnels. The heat release capacity of the surrounding rocks of the roadways is significantly reduced after introducing a thermal insulation layer into the roadway design under different schemes; these design schemes were determined by further engineering example analysis. It was found that the heat insulation layer design can cool the surrounding rocks of deep mine roadways.

scholarly journals Experimental Study on the Temperature Field of Cold Region Tunnel under Various Groundwater Seepage Velocities

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shiding Cao ◽  
Taishan Lu ◽  
Bo Zheng ◽  
Guozhu Zhang
Keyword(s):  
Temperature Field ◽  
Coupling Effect ◽  
Calculation Model ◽  
Surrounding Rock ◽  
Laboratory Model ◽  
Interface Temperature ◽  
Cold Region ◽  
Seepage Velocity ◽  
Groundwater Seepage ◽  
Tunnel Cross Section

Groundwater seepage significantly affects the temperature field of a cold region tunnel. Laboratory model tests are carried out to evaluate its effects, yielding four main results. First, groundwater seepage can increase tunnel air temperature and decrease the thickness and length of the tunnel insulation layer. Second, groundwater seepage and tunnel ventilation exert a coupling effect on the surrounding rock temperature. This effect is related to the surrounding rock depth. Third, the influence of the groundwater seepage velocity on the temperature of the interface between the lining and surrounding rock demonstrates a spatial difference, and the groundwater seepage leads to an uneven temperature distribution at the interface between the lining and surrounding rock. Furthermore, under groundwater seepage, the shape and size of the tunnel cross section have significant effects on the interface temperature. Fourth, the cold region tunnel has an antifreezing capability that is mainly related to the frost heaving of the surrounding rock and the groundwater seepage velocity. This capability should be fully utilized in the design of cold region tunnels. The experimental data presented can be used to verify the reliability of the theoretical calculation model for tunnel temperatures in cold regions.

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