scholarly journals Stability Analysis of Host Claystone under T-M Coupling of HLW Disposal Repository in China: Experiments and Numerical Simulation

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Haian Liang ◽  
Tan Tang ◽  
Longpeng Zhang ◽  
Xiaodong Liu ◽  
Shuai Liu ◽  
...  
Keyword(s):  
Numerical Model ◽  
Heat Release ◽  
Failure Modes ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
Clay Rock ◽  
Deformation And Failure ◽  
Rock Samples ◽  
The Stability

This paper focuses on the stability of the high-level radioactive waste (HLW) in the proposed clay rock in Tamusu area of China. The in-situ stress as well as the variational characteristics of ambient temperature caused by nuclide decay during HLW storage should be noticeable. A series of thermal property tests and thermo-mechanical coupled strength (T-M) tests of rock samples in the target formation are carried out. Then the stability of surrounding rock of an HLW under the combination of heat release from HLW and in-situ stress is simulated and analyzed by numerical method. Thermal properties of Tamusu clay rock samples are obtained by testing their thermal conductivity. In order to obtain the characteristics and the failure modes of rock samples at different temperatures, the T-M coupling experiments in the temperature range of 100°C are conducted. Numerical model for simulating the state of operation of the nuclear waste tank buried in the tunnel within 100 years is constructed. A thermal boundary by the heat release equation of HLW and the real in-situ stress level in Tamusu area are considered in the model. While, the variation law of surrounding rock’s temperature, stress, and deformation corresponding to the embedding time is obtained from the numerical calculation. Finally, the stability of the deep geological repository is comprehensively evaluated. The results show that the temperature has a significant impact on the T-M coupling characteristics of Tamusu clay rock, and the proposed repository numerical model has no large deformation and failure problems in 100 years. However, the temperature of the surrounding rock of the repository may exceed the safety standard value during the operation period.

scholarly journals Analytical Solution of Tunnel Surrounding Rock for Stress and Displacement Based on Lade–Duncan Criterion

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
MingZheng Zhu ◽  
Yugui Yang ◽  
Feng Gao ◽  
Juan Liu
Keyword(s):  
Internal Friction ◽  
Plastic Zone ◽  
Yield Criterion ◽  
Surrounding Rock ◽  
Rock Stress ◽  
Deformation And Failure ◽  
Displacement Based ◽  
The Stability ◽  
Coulomb Criterion

The deformation and failure of tunnel surrounding rock is the result of tunnel excavation disturbance and rock stress release. When the local stress of surrounding rock exceeds the elastic limit of rock mass, the plastic analysis of surrounding rock must be carried out to judge the stability of tunnel. In this study, the Lade–Duncan yield criterion is used to calculate the analytic solutions for the surrounding rock in a tunnel, and the radius and displacement of the plastic zone are deduced using an equilibrium equation. The plastic zone radius and displacement based on Lade–Duncan criterion and Mohr–Coulomb criterion were compared by using single-factor analysis method under the different internal friction angles, in situ stresses, and support resistances. The results show that the solutions of the radius and displacement of plastic zone calculated by the Lade–Duncan criterion are close to those of Mohr–Coulomb criterion under the high internal friction angle and support resistance or low in situ rock stress; however, the radius and displacement of the plastic zone calculated by the Lade–Duncan criterion are larger under normal circumstances, and the Lade–Duncan criterion is more applicable to the stability analysis of the surrounding rock in a tunnel.

Study of the Trellis Support of Working Face Roadway in Impact Coal Seam

2014 ◽  
Vol 941-944 ◽  
pp. 2558-2564
Author(s):  
Yu Kai Lv ◽  
Cong Jiang ◽  
Yao Dong Jiang
Keyword(s):  
In Situ Stress ◽  
Surrounding Rock ◽  
Mine Pressure ◽  
Working Face ◽  
Coal Bumps ◽  
Roadway Support ◽  
The Stability ◽  
The Impact ◽  
Physical And Mechanical Characteristics

Coal bumps happened many times in mining at No.5 seam of Tangshan coal mine. Strengthen the roadway’s support of working face can effectively reduce disaster losses. With the research background of the 3654 working face, the mine pressure monitoring for the existing support form of roadway has been carried on. Perform a numerical simulation for the original roadway support, base on the in-situ stress and physical and mechanical characteristics of surrounding rock in experimental; study the impact of the stability of roadway’s surrounding rock, while the space change of trellis and change of supporting intensity; optimizing the original support form, so as to maximum reducing the impact of the coal bumps.

Theoretical Study on Coal Mine In Situ Stress’s Monitoring Method

2013 ◽  
Vol 446-447 ◽  
pp. 1113-1117 ◽  
Author(s):  
Hong Biao Wang ◽  
Chao An ◽  
Shan Dong Zhang
Keyword(s):  
Coal Mine ◽  
In Situ Stress ◽  
Mining Engineering ◽  
Stress Monitoring ◽  
Working Process ◽  
Monitoring Method ◽  
Deformation And Failure ◽  
The Stability ◽  
Dynamic Phenomena

For mine mining, In-situ stress is the fundamental force that causes the deformation and failure of surrounding rock in the mining engineering and supporting, and produces mine dynamic phenomena. Among many factors which affecting the stability of mining engineering, In-situ stress is the main and one of the most fundamental factors. According to the In-situ stress monitoring method some coal mine adopted, this paper introduces the concrete principle and working process.

scholarly journals Effect of Axial In-Situ Stress in Deep Tunnel Analysis Considering Strain Softening and Dilatancy

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1502
Author(s):  
Kang Yi ◽  
Zhenghe Liu ◽  
Zhiguo Lu ◽  
Junwen Zhang ◽  
Shuangyong Dong
Keyword(s):  
Plastic Flow ◽  
Strain Softening ◽  
Axial Stress ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
Deep Tunnel ◽  
Support Design ◽  
Deformation And Failure ◽  
Initial Yield

In many previous tunnel analyses, the axial in-situ stress was ignored. In this work, its effect on the deformation and failure of the surrounding rock of a deep tunnel was revealed, considering the objective strain softening and dilatancy behavior of the surrounding rock. Analysis based on the incremental plastic flow theory was conducted, and C++ was used to write a constitutive model for numerical simulation to verify and further analyze this effect. Then, the results were validated by the field monitoring data of a coal mine gateway. Results show that the effect of the axial in-situ stress σa0 is more significant when strain softening is considered, compared with the results of a perfectly elastoplastic model. When the axial stress σa is σ1 or σ3 at the initial yield, an increase or decrease in σa0 intensifies the deformation and failure of the surrounding rock. When σa is σ2 at the initial yield, 3D plastic flow partly controlled by σa may occur, and an increase in σa0 intensifies the deformation and failure of the surrounding rock. The effect of σa0 will be amplified by considering dilatancy. Considering both strain softening and dilatancy, when σa0 is close to the tangential in-situ stress σt0 or significantly greater than σt0 (1.5 times), σa will be σ2 or σ1 at the initial yield, and then 3D plastic flow will occur. In the deformation prediction and support design of a deep tunnel, σa0 should not be ignored, and the strain softening and dilatancy behavior of the surrounding rock should be accurately considered.

Study on Excavation Procedure of Dawangou Shallow Tunnel under Unsymmetrical Pressure

2013 ◽  
Vol 353-356 ◽  
pp. 1539-1542
Author(s):  
Su Chao Xu ◽  
T. Y. Liu ◽  
C.Y. Jin
Keyword(s):  
Rock Mass ◽  
In Situ Stress ◽  
Comprehensive Analysis ◽  
Surrounding Rock ◽  
Shallow Tunnel ◽  
Mechanical Index ◽  
Plastic Zones ◽  
Simulation Results ◽  
The Stability

The performance of a tunnel is influenced by such factors as the size and shape of the opening, the in-situ stress and the deformation field and also properties of the rock mass. Different excavation procedures have great important influence on the stability of the surrounding rock, especially for tunnels under unsymmetrical pressure. In this paper, flac3D is used in the simulation of different excavation sequence for Dawanggou tunnel in order to analyze the variation of plastic zones and deformation of the surrounding rock. The numerical results indicate that the mechanical index is different due to variant excavation plans and an optimized plan is determined based on the comprehensive analysis of the index gained from the simulation results.

The Stress Distribution and Calculation of the Different Zone of Wellbore Surrounding Rock Based on the Damaged Theory

2012 ◽  
Vol 170-173 ◽  
pp. 1052-1055
Author(s):  
Wan Chun Zhao ◽  
Chen Yan Sun ◽  
Ting Ting Wang ◽  
Yu Liu ◽  
Cai Ping Yang
Keyword(s):  
Stress Distribution ◽  
Stress Field ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
Oil Well ◽  
Damage Area ◽  
Stress Direction ◽  
The Stability ◽  
Adjacent Rock

In order to describe the stability of borehole face and the theory of hydraulic fracture fissure stretch in real, the stress field of adjacent rock in the hole should be constituted exactly .The article is based on the damnification dynamics theory, meanwhile, considered the rock is fracture-pore dual medium and the damnification characteristic of the rock in hole .Adjacent formation is sectioned three areas: damage-area, damnification-area, elasticity-area. And we have calculated the ambient stress distribution of one oil-well .The results show that the destructive radius of the minimum in-situ stress direction is 1.247m, the damage radius is 8.082m, the destructive radius of the maximum in-situ stress direction is 0.998m, and the damage radius is 6.5865m.

Analysis on Types of In Situ Stress Field and its Effect to Roadway in Deep Coal Mines

2011 ◽  
Vol 90-93 ◽  
pp. 353-358
Author(s):  
Chao Ru Liu
Keyword(s):  
Stress Concentration ◽  
Plastic Zone ◽  
Coal Mines ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
Stress Fields ◽  
Different Types ◽  
The Stability ◽  
Two Sides

By analyzing a large number of in-situ stress data measured in underground deep coal mines, two types of in-situ stress fields exit in deep coal mines, σHvh and σvHh, which influences on the stability of underground deep roadways are analyzed by means of numerical simulation. The results show that the destruction of surrounding rock varies greatly in equal value stress fields with different types. In σHvh, the plastic zone of roof and floor of roadways is larger than the two sides, and stress concentration appears in front of heading face and in roof and floor of roadways, but not in two sides, more considerations should be given to the roof and floor supporting. In σvHh, plastic zone of two sides is larger than the roof and floor, and stress concentration appears in front of heading face and the sides of roadways, but not in the roof and floor, so more supporting considerations should be given to the two sides while protecting the roof.

Research on 2D Limit Equilibrium Method of Slopes Considering the Effect of Horizontal In Situ Stress

2013 ◽  
Vol 671-674 ◽  
pp. 245-250
Author(s):  
Wen Hui Tan ◽  
Ya Liang Li ◽  
Cong Cong Li
Keyword(s):  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
In Situ Stress ◽  
Open Pit ◽  
Open Pit Mines ◽  
Equilibrium Method ◽  
Iron Mine ◽  
The Stability ◽  
Slice Method

At present, in-situ stress was not considered in Limit Equilibrium Method (LEM) of slopes, the influence of in-situ stress is very small on the stability of conventional slopes, but in deep-depressed open-pit mines, the influence should not be neglected. Formula for calculating the Factor of Safety (FOS) under the effect of horizontal in-situ stress was deduced using General Slice Method (GSM) of two-dimensional (2D) limit equilibrium method in this paper，a corresponding program SSLOPE was built, and the software was used in a deep- depressed open-pit iron mine. The results show that the FOS of the slope decreased by 20% when horizontal in-situ stress is considered, some reinforcements must be taken. Therefore, the influence of in-situ stress on slope stability should be taken into account in deep open –pit mines.

Judgement Method for Surrounding Rock Stability of Guanjiao Tunnel Based on Catastrophe Theory

2011 ◽  
Vol 90-93 ◽  
pp. 2307-2312 ◽  
Author(s):  
Wen Jiang Li ◽  
Su Min Zhang ◽  
Xian Min Han
Keyword(s):  
Plastic Strain ◽  
Catastrophe Theory ◽  
Soft Rock ◽  
Surrounding Rock ◽  
In Situ Monitoring ◽  
Engineering Practice ◽  
Stability Of Surrounding Rock ◽  
The Stability ◽  
Rock Tunnel

The stability judgement of surrounding rock is one of the key jobs in tunnel engineering. Taking the Erlongdong fault bundle section of Guanjiao Tunnel as the background, the stability of surrounding rock during construction of soft rock tunnel was discussed preliminarily. Based on plastic strain catastrophe theory, and combining numerical results and in-situ data, the limit displacements for stability of surrounding rock were analyzed and obtained corresponding to the in-situ monitoring technology. It shows that the limit displacements obtained corresponds to engineering practice primarily. The plastic strain catastrophe theory under unloading condition provides new thought for ground stability of deep soft rock tunnel and can be good guidance and valuable reference to construction decision making and deformation managing of similar tunnels.

Study on Deformation and Damage of Rock Mass Subject to High In Situ Stress by Using a Elastoplastic Damage Model and Considering the Impact of Weak Planes

2013 ◽  
Vol 838-841 ◽  
pp. 705-709
Author(s):  
Yun Hao Yang ◽  
Ren Kun Wang
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Damage Model ◽  
Back Analysis ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
High In Situ Stress ◽  
Underground Caverns ◽  
The Impact

Large scale underground caverns are under construction in high in-situ stress field at Houziyan hydropower station. To investigate deformation and damage of surrounding rock mass, a elastoplastic orthotropic damage model capable of describing induced orthotropic damage and post-peak behavior of hard rock is used, together with a effective approach accounting for the presence of weak planes. Then a displacement based back analysis was conducted by using the measured deformation data from extensometers. The computed displacements are in good agreement with the measured ones at most of measurement points, which confirm the validities of constitutive model and numerical simulation model. The result of simulation shows that damage of surrounding rock mass is mainly dominated by the high in-situ stress rather than the weak planes and heavy damage occur at the cavern shoulders and side walls.

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