Modeling of tunneling-induced ground surface movements using stochastic medium theory

2004 ◽  
Vol 19 (2) ◽  
pp. 113-123 ◽  
Author(s):  
J.S. Yang ◽  
B.C. Liu ◽  
M.C. Wang
Keyword(s):  
Ground Surface ◽  
Stochastic Medium ◽  
Medium Theory

scholarly journals Analytical Solution of Three-Dimensional Heaving Displacement of Ground Surface during Tunnel Freezing Construction Based on Stochastic Medium Theory

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Hai-bing Cai ◽  
Meng-kai Li ◽  
Xiao-fang Li ◽  
Sheng Li ◽  
Rong-bao Hong
Keyword(s):  
Analytical Solution ◽  
Prediction Model ◽  
Inclination Angle ◽  
Three Dimensional ◽  
Ground Surface ◽  
Stochastic Medium ◽  
Medium Theory ◽  
Calculation Results ◽  
Practical Engineering ◽  
Center Axis

Many studies indicate that the heaving displacement during tunnel freezing construction can be regarded as a plane strain problem. However, due to the fact that many of the frozen pipes are placed obliquely in practical engineering, it should be a three-dimensional problem. Therefore, considering stochastic medium theory, the analytical solution of three-dimensional heaving displacement of ground surface during tunnel freezing construction is established, and the analytical solution is applied to the project case in Beijing. The calculation results show that, considering the inclination angle between the freezing pipe and the center axis of the tunnel, the maximum heaving displacement of the ground surface occurs at the tunnel center. When the inclination angle is equal to 0°, the analytical solution of three-dimensional ground surface heaving displacement is in good agreement with that of the two-dimensional prediction model, which further verified the reliability of the established analytical solution of the three-dimensional frost heave prediction model.

scholarly journals Ground Movement Analysis Based on Stochastic Medium Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Meng Fei ◽  
Wu Li-chun ◽  
Zhang Jia-sheng ◽  
Deng Guo-dong ◽  
Ni Zhi-hui
Keyword(s):  
Distribution Function ◽  
Back Analysis ◽  
Movement Analysis ◽  
Measured Data ◽  
Ground Movement ◽  
Pile Driving ◽  
Normal Distribution Function ◽  
Stochastic Medium ◽  
Medium Theory ◽  
Vertical Ground

In order to calculate the ground movement induced by displacement piles driven into horizontal layered strata, an axisymmetric model was built and then the vertical and horizontal ground movement functions were deduced using stochastic medium theory. Results show that the vertical ground movement obeys normal distribution function, while the horizontal ground movement is an exponential function. Utilizing field measured data, parameters of these functions can be obtained by back analysis, and an example was employed to verify this model. Result shows that stochastic medium theory is suitable for calculating the ground movement in pile driving, and there is no need to consider the constitutive model of soil or contact between pile and soil. This method is applicable in practice.

scholarly journals A New Modified Peck Formula for Predicting the Surface Settlement Based on Stochastic Medium Theory

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Zhanping Song ◽  
Xiaoxu Tian ◽  
Yuwei Zhang
Keyword(s):  
Friction Angle ◽  
Surface Settlement ◽  
Calculation Error ◽  
Stochastic Medium ◽  
Medium Theory ◽  
Comparison Results ◽  
Calculation Process ◽  
The Difference ◽  
Shallow Buried Tunnel ◽  
Prediction Approach

Peck method and stochastic medium method are the two most commonly used methods to estimate surface settlement caused by tunnel excavation. However, the Peck method was not suitable for a shallow-buried tunnel, and the calculation process of the stochastic medium theory was complicated. To solve this problem, in this paper, a simple and accurate prediction approach for surface settlement was obtained by improving the Peck method based on the basic idea of stochastic medium theory. In detail, the over-excavation area of the tunnel was divided into n independent units, and the surface settlement caused by the collapse of each unit was calculated, respectively. Then, the total surface settlement can be obtained by superimposing surface settlement induced by each unit. Taking the shallow-buried section of Mulingguan tunnel entrance as a case, the surface settlement calculated by the modified Peck formula and original Peck formula was compared with the observed data, respectively. The comparison results indicated that the surface settlement calculated by the modified Peck formula is closer to the observed data than that calculated by the original Peck formula in the calculation process of surface settlement of shallow-buried tunnel. The table of recommendation for the number of units can be obtained by a discussion of reasonable n values. Finally, the difference between the original Peck formula and the modified Peck formula was analysed, and the results showed that the change rule of the surface settlement is consistent under the tunnel depth, internal friction angle, and ground loss of the tunnel. However, the calculation error of the surface settlements calculated by the original Peck formula is more significant than that calculated by modified Peck formula under the tunnel diameter ratio being less than 1.75. The modified Peck formula is more suitable for calculating the surface settlement under internal angle friction being less than 20° or greater than 40°. The research results expand the scope of application of the original Peck formula and enrich the calculation approach of surface settlement induced by underground excavation in tunnel construction.

Influence Mechanism of Isolation Layer to Granular Media Flow

2012 ◽  
Vol 256-259 ◽  
pp. 2514-2518
Author(s):  
Yun Xiang Liu ◽  
Qing Fa Chen ◽  
Hong Qi Chen
Keyword(s):  
Granular Media ◽  
Working Condition ◽  
Underground Mining ◽  
Particle Flow Code ◽  
Radius Of Curvature ◽  
Stochastic Medium ◽  
Medium Theory ◽  
Isolation Layer ◽  
Influence Mechanism ◽  
Shrinkage Method

By using particle flow code (PFC2D), influence mechanism of isolation layer to granular media flow was studied by simulating two ore-drawing modes of filling mining method (working condition Ⅰ) and synchronous filling shrinkage method(working condition Ⅱ). After analyzed simulation results, some laws were gotten: (1) by the fitting process conducted on released volume and height, it is found that the relationship of released volume and height was power equation, which is same as the stochastic medium theory for ore-drawing; (2) The released volume, the size in most width of loosing body and the location of working condition Ⅱ was both bigger than those of working condition Ⅰ; (3) the radius of curvature of drawn-funnel of working conditionⅡ was bigger than those of working conditionⅠ, but the volume of residual ore was opposite. Analysis shows that the isolation layer reduced the contact force in ore drawing regional, made the porosity bigger, so as to improve liquidity. The results provide a theoretical reference for the changes in underground mining techniques and ore-drawing control.

Caving mechanisms of loose top-coal in longwall top-coal caving mining based on stochastic medium theory

2018 ◽  
Vol 11 (20) ◽  
Author(s):  
Dijie Zhu ◽  
Zhonghui Chen ◽  
Weisheng Du ◽  
Lingfan Zhang ◽  
Zihan Zhou
Keyword(s):  
Stochastic Medium ◽  
Medium Theory ◽  
Longwall Top Coal Caving

Analysis of Ground Movement in Pile Driving Based on Stochastic Medium Theory

2013 ◽  
Vol 438-439 ◽  
pp. 1404-1408 ◽  
Author(s):  
Fei Meng ◽  
Jia Sheng Zhang ◽  
Hui Ying Liu
Keyword(s):  
Axisymmetric Problem ◽  
Back Analysis ◽  
Measured Data ◽  
Ground Movement ◽  
Pile Driving ◽  
Normal Distribution Function ◽  
Stochastic Medium ◽  
Medium Theory ◽  
Vertical Ground ◽  
Soil Interface

In order to calculate the ground movement induced by displacement piles driven into horizontal layered soil, it is simplified to an axisymmetric problem. Then the vertical and horizontal ground movement functions were deduced based on stochastic medium theory. The vertical ground movement is a normal distribution function, while the horizontal ground movement is an exponential function. Utilizing field measured data, parameters of these functions can be obtained by back analysis. The example indicates that the stochastic medium theory is suitable for calculating the ground movement in pile driving, and there is no need to consider the constitutive model of soil or contact model of pile-soil interface in calculation. This method is fairly applicable in practice, and can provide a reference for related research.

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