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.

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 Investigation of Ground and Air Temperature Fields of a Cold-Region Road Tunnel in NW China

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Hao Wu ◽  
Yujian Zhong ◽  
Wei Xu ◽  
Wangshuaiyin Shi ◽  
Xinghao Shi ◽  
...  
Keyword(s):  
Temperature Field ◽  
Wind Speed ◽  
Longitudinal Direction ◽  
Frost Damage ◽  
Temperature Fields ◽  
Tibet Plateau ◽  
Test Results ◽  
Road Tunnel ◽  
Cold Region ◽  
Drainage Pipe

To fully understand the temperature distribution of cold regions and the variation law of temperature fields in cold-region tunnels, this paper presents a case-history study on a tunnel located on the eastern Qinghai-Tibet Plateau, China. The conclusion is as follows: the temperature outside the tunnel and the ambient temperature are affected by wind speed and light. The law of the temperature field in the tunnel is greatly affected by wind speed and wind direction. According to the field test, the wind speed in the tunnel is about 2.8 m/s in winter, and the daily average temperature at the exit of the tunnel is basically lower than that at the entrance. From the central to the entrance, the temperature in the tunnel decreases by 0.11°C every 10 meters along the longitudinal direction; from the central to the exit, the temperature in the tunnel increases by 0.07°C every 10 meters. In this regard, for the problems of lining frost damage and central drainage pipe freezing, it is suggested to adopt the way of heating and drainage, but heating the freezing area outside the drainage pipe should be avoided. The test results can provide references for the design, construction, and research of the temperature field of the tunnel antifreezing system in the cold region. It is hoped that the test results can be useful in the design and construction of frost damage prevention systems and the investigation of temperature fields in cold-region tunnels.

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

Strip Insulating Layer in Tunnel in Cold Region and its Temperature Field Analysis

2012 ◽  
Vol 170-173 ◽  
pp. 1679-1684 ◽  
Author(s):  
Kang Cheng Lu ◽  
Chao Chao Ma ◽  
Zhe Ji ◽  
Peng Xu
Keyword(s):  
Temperature Field ◽  
Drainage System ◽  
Field Analysis ◽  
Insulation Layer ◽  
Cold Region ◽  
Element Analysis ◽  
Drain Pipe ◽  
Insulating Layer ◽  
Warming Period ◽  
Drainage Pipe

Strict waterproof is the key to prevent frost damage to tunnel in the cold region. Improving drainage system has benefits to obtain good waterproof effect. Aim at the drain pipe freeze in cooling and warming period, we design a strip partial insulating layer to the drainage system :(1) The girth drainage pipe connects to the central drainage pipe directly, and the lengthways drainage pipe connects to the girth drainage pipe by tee. (2) Interval decorating insulation layer to the tunnel girth drainage pipe, using the strip insulation layer behind the lining and setting annular insulation around drainage pipe under the tunnel road. (3) The strip insulation layer is sandwiched by two layers of flashing; one of them forms a whole system with the tunnel flashing and the other posts on its surface. The temperature field finite element analysis of surrounding rock and lining concrete show that: As the girth drainage pipe if there is insulation layer is placed with a certain interval between each other. Two kinds of drain pipe's freeze-thaw state has a time gap. It is beneficial to solve the problem of the poor drainage after the lining in the cooling and warming period.

scholarly journals An Analytical Solution for the Frost Heaving Force considering the Freeze-Thaw Damage and Transversely Isotropic Characteristics of the Surrounding Rock in Cold-Region Tunnels

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Jiabing Zhang ◽  
Xiaohu Zhang ◽  
Helin Fu ◽  
Yimin Wu ◽  
Zhen Huang ◽  
...  
Keyword(s):  
Analytical Solution ◽  
Transversely Isotropic ◽  
Frost Damage ◽  
Surrounding Rock ◽  
Cold Region ◽  
Frost Heaving ◽  
Power Series Method ◽  
Variable Theory ◽  
Freeze Thaw ◽  
Bedding Angle

Frost damage is a frequent occurrence in cold regions and can threaten the normal use and structural stability of tunnel engineering projects. To accurately determine the frost heaving force and effectively evaluate the frost damage in cold-region tunnels, an analytical solution for the frost heaving force considering the freeze-thaw (F-T) damage and transversely isotropic characteristics of surrounding rock is presented based on complex variable theory and the power series method. The calculation results indicate that the frost heaving force acts on the lining considering that the transversely isotropic characteristics of surrounding rock are significantly greater than those when assuming the surrounding rock is homogeneous isotropic media. This demonstrates that the transversely isotropic characteristics of surrounding rock have a considerable impact on the frost heaving force and should be considered. The frost heaving force continuously increases as the bedding angle increases from 0° to 90°, and the maximum frost heaving force in the Guanjiao tunnel (the rock mass bedding angle is 30°) of the Xining-Geermu Railway in China is approximately 1.04 MPa. In addition, the influence of F-T cycles on the frost heaving force in cold-region tunnels is investigated based on the analytical solution of the frost heaving force proposed in this paper. The frost heaving force acting on the lining decreases with an increasing number of F-T cycles due to the deterioration of the mechanical parameters of the surrounding rock.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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