Analysis of a Couple of Problemsof Ground Stress and Temperature Stress Fields in Tunnel of Fissured Surrounding Rock in Cold Region

Logistics ◽  
2009 ◽  
Author(s):  
Bing Sun ◽  
Wenge Qiu ◽  
Mingfang Wu
Keyword(s):  
Temperature Stress ◽  
Surrounding Rock ◽  
Stress Fields ◽  
Cold Region ◽  
Ground Stress

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 Analysis of Tunnel Water Inrush Considering the Influence of Surrounding Rock Permeability Coefficient by Excavation Disturbance and Ground Stress

2021 ◽  
Vol 11 (8) ◽  
pp. 3645
Author(s):  
Helin Fu ◽  
Pengtao An ◽  
Long Chen ◽  
Guowen Cheng ◽  
Jie Li ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Water Pressure ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Water Inflow ◽  
Calculation Error ◽  
External Water Pressure ◽  
Ground Stress ◽  
External Water ◽  
Inflow Prediction

Affected by the coupling of excavation disturbance and ground stress, the heterogeneity of surrounding rock is very common. Presently, treating the permeability coefficient as a fixed value will reduce the prediction accuracy of the water inflow and the external water pressure of the structure, leading to distortion of the prediction results. Aiming at this problem, this paper calculates and analyzes tunnel water inflow when considering the heterogeneity of permeability coefficient of surrounding rock using a theoretical analysis method, and compares with field data, and verifies the rationality of the formula. The research shows that, when the influence of excavation disturbance and ground stress on the permeability coefficient of surrounding rock is ignored, the calculated value of the external water force of the tunnel structure is too small, and the durability and stability of the tunnel are reduced, which is detrimental to the safety of the structure. Considering the heterogeneity of surrounding rock, the calculation error of water inflow can be reduced from 27.3% to 13.2%, which improves the accuracy of water inflow prediction to a certain extent.

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.

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.

Grey Correlation Analysis on the Sensitive Factors of Plastic Zone Extension of Surrounding Rock

2013 ◽  
Vol 438-439 ◽  
pp. 1210-1216
Author(s):  
Xuan Rong Zheng
Keyword(s):  
Correlation Analysis ◽  
Plastic Zone ◽  
Deformation Modulus ◽  
Friction Angle ◽  
Surrounding Rock ◽  
Unit Weight ◽  
Analysis Method ◽  
Grey Correlation ◽  
Grey Correlation Analysis ◽  
Ground Stress

As lack of explicit analysis method on the sequence of many factors influencing the plastic zone extension of surrounding rock, the grey correlation analysis method is adopted to study the relationship between the plastic zone extension radius Rp and the six factors such as cohesive c, internal friction angle φ, deformation modulus E, unit weight γ, initial ground stress σ and the radius of chamber r. By dealing with dimensionless, the corresponding sequences composed with the sensitive factors as sub-sequence and the plastic zone extension radius as mother sequence are obtained. The gray correlation analysis model of sensitive factors which evaluates the results with grey correlation degree is built by the methods of dimensionless and extreme difference variation. Then, an engineering example is analyzed with grey correlation. Based on the analysis results, the sorting of sensitive factors is φ > σ > c > r > E > γ. It implies that the influences of internal friction angle φ and initial ground stress σ are the most prominent, and the sensitivities of deformation modulus E and unit weight γ are lowest. These are in good agreement with the analytical formula of classical theory, and can be used in guiding the further optimization and improvement of the analytical expression of the plastic zone extension radius Rp of surrounding rock.

scholarly journals Comparative Study of Wellhole Surrounding Rock under Nonuniform Ground Stress

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Zhongyu Jiang ◽  
Guoqing Zhou
Keyword(s):  
Homogeneous Equation ◽  
Pressure Coefficient ◽  
Circumferential Stress ◽  
Surrounding Rock ◽  
Special Solution ◽  
Operator Matrix ◽  
Specific Expression ◽  
Symplectic Algorithm ◽  
Ground Stress ◽  
The Relationship

The stress analysis of the wellhole surrounding rock and the regular failure of the wellhole has always been a concern for the well builders. Firstly, the Hamilton canonical equations are obtained by using the Hamiltonian variational principle in the sector domain, and the zero eigensolution and nonzero eigensolutions of the homogeneous equation are solved. According to the Hamiltonian operator matrix with the orthogonal eigenfunction system, the special solution form of the nonhomogeneous boundary condition equation is obtained. Then, according to the principle of the same coefficient being equal, the relationship equation between the direction eigenvalue and the angle coefficient is obtained, from which the specific expression of the special solution of the equation can be determined. Furthermore, the analytical solution of the wellhole surrounding rock problem under nonuniform ground stress is obtained by using the linear elastic accumulative principle. Finally, a concrete example is given to compare the finite element method and the symplectic algorithm. The results are consistent, which ensures the accuracy and the reliability of the symplectic algorithm. The relationship between the circumferential stress distribution around the hole and the lateral pressure coefficient is further analyzed.

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