Research on Surrounding Rock Stability by Ideal Point-Rough Set Efficacy Coefficient Method

2013 ◽  
Vol 353-356 ◽  
pp. 415-420 ◽  
Author(s):  
Guo Ren Lu ◽  
Le Wen Zhang ◽  
Dao Hong Qiu ◽  
Xiao Feng

The ideal point method is a kind of multiple-goal decision analysis method, the basic idea is to construct the ideal and anti-ideal solution of multi attribute problem, with degree that near ideal solution and away from the anti-ideal solution as the basis to judge each evaluation object. Based on the basic principle of ideal point method, and comprehensive consideration of the actual geological conditions of Qingdao metro, we selected rock compressive strength, integrity coefficient, structure surface behavior, groundwater and softening coefficient as the evaluation factors of surrounding rock stability, and used the rough set theory to determine the index weight. At last, established the evaluate model for the surrounding rock stability of metro based on the rough set efficacy coefficient method. The research show that the stability analysis results are consistent with the actual excavation, so using rough set efficacy coefficient method to analysis surrounding rock stability of Qingdao Metro is feasible, which provides a new idea for the stability analysis of surrounding rock.

2014 ◽  
Vol 501-504 ◽  
pp. 1732-1735
Author(s):  
Jie Liu ◽  
Liang Tang ◽  
Ya Zuo ◽  
Jin Long Guo

Analyzing and Evaluating the stability of the surrounding rock is an indispensable and important part in the tunnel design. In this paper, the surrounding rock stability of Danba hydropower station diversion tunnel is dealt with, FLAC3Dsoftware is used for stability analysis. Selecting three different cross sections for calculation models, comparing with the displacement and principal stress and the plastic zone which calculated by FLAC3D, we can evaluate their stability and get the best diversion tunnel design.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yingchao Wang ◽  
Ning Zhao ◽  
Hongwen Jing ◽  
Bo Meng ◽  
Xin Yin

The classification of surrounding rock stability is the critical problem in tunneling engineering. In order to decrease engineering disasters, the surrounding rock stability should be accurately evaluated. The ideal point method is applied to the classification of surrounding rock stability. Considering the complexity of surrounding rock classification, some factors such as rock uniaxial compressive strengthen, integrality coefficient of rock mass, the angle between tunnel axis and the main joint, joints condition, and seepage measurement of groundwater are selected as evaluation indices. The weight coefficients of these evaluation indices are determined by the objective and subjective weighting method, consisting with the delphi method and the information entropy theory. The objective and subjective weighting method is exact and reliable to determine the weights of evaluation indices, considering not only the expert’s experiences, but also objectivity of the field test data. A new composite model is established for evaluating the surrounding rock stability based on the ideal point method and the objective and subjective weighting method. The present model is applied to Beigu mountain tunnel in Jiangsu province, China. The result is in good agreement with practical situation of surrounding rock, which proves that the ideal point method used to classify the surrounding rock in tunnels is reasonable and effective. The present model is simple and has very strong operability, which possesses a good prospect of engineering application.


2014 ◽  
Vol 577 ◽  
pp. 1135-1138
Author(s):  
Bing He ◽  
Guang Zhi Yin

This paper combines the geological condition of Miaoziwan tunnel and numerical simulation software ANSYS to analyze the displacement and stress condition of surrounding rock before and after the excavation. Furthermore, the stability of overlying rock in the tunnel was studied based on the displacement and stress condition of surrounding rock. The breaking law of overlying rock was studied considering the influencing factors to the stability of surrounding. The study and analysis to the breaking law of overlying rock can be helpful to the improvement of surrounding rock stability control and supporting system. Moreover, the result can be the guidance to the excavation.


2011 ◽  
Vol 105-107 ◽  
pp. 1555-1560 ◽  
Author(s):  
Si Yang Chen ◽  
Zhong Li ◽  
Tian Yu Zhang ◽  
Hua Wen Ou

This paper analyzes the tunnel rock ultimate displacement,proposes using acceleration to determine the tunnel surrounding rock stability.Acceleration compared to determine the stability of surrounding rock ultimate displacement method obtained consistent results.Acceleration improved the ultimate displacement method to determine the shortcomings are difficult to quantify.Acceleration of rock deformation by the positive and negative judgments, rock deformation can clearly reflect the trends and status, you can clearly see which one works in a specific state of rock a dangerous warning signal.With a typical project examples validate the method used to determine the displacement acceleration stability of surrounding rock is accurate, feasible.Research and analysis to help build a tunnel surrounding rock stability analysis of the forecasting system.


2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua

Based on the special geological conditions of a tunnel in Qingyuan section of Huizhou-Zhanzhou Expressway, FLAC3d numerical simulation software is used to simulate the rheological properties and instability of surrounding rock in large-section fully weathered sandstone section, and the stability and loss of surrounding rock are analyzed. The deformation of the dome and the face at steady state is analyzed. It is found that: 1) when the surrounding rock is in a stable state, the deformation curve of the dome is smooth. When the surrounding rock of the face is unstable, the front of the face appears ahead. Deformation should be first strengthened on the surrounding rock in front of the face. 2) The arched foot is an important part of the instability of the surrounding rock. In order to prevent the expansion of the collapsed part, the arched part should be reinforced. 3) In order to obtain the limit state of surrounding rock stability, the strength of surrounding rock is reduced, and the strength reduction coefficient corresponding to the displacement sudden point is taken as the safety factor of rock stability around the hole, and the stability safety coefficients of surrounding rock of each construction step are greater than 1.2. 4) The dynamic standard values of deformation control in the whole construction stage are obtained by analyzing the deformation curves of each data monitoring point with time in the corresponding time period of each construction step.


2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.


2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jucai Chang ◽  
Kai He ◽  
Zhiqiang Yin ◽  
Wanfeng Li ◽  
Shihui Li ◽  
...  

In view of the influence of mining stress on the stability of the surrounding rock of inclined roof mining roadways in deep mines, the surrounding rock stability index is defined and solved based on the rock strength criterion and the stress distribution. The mining roadway of the 17102(3) working face of the Pansan Coal Mine is used as the engineering background and example. The surrounding rock’ stabilities under the conditions of no support and bolt support are analyzed according to the surrounding rock’s stability index and the deformation data. The results show that the areas of low wall and high wall instability are 1.68 m2 and 2.12 m2, respectively, and the low wall is more stable than the high wall; the areas of the roof and floor instability are 0.33 m2 and 0.35 m2, respectively, and the roof and floor are more stable than the two sides. During mining, the area of instability greatly increases at first, then decreases to 0, and reaches a maximum value at the peak of the abutment pressure. The stability of the surrounding rock decreases first and then increases. Compared with the end anchoring bolt support, the full-length anchoring bolt support reduces the area of instability to a greater extent, and the full-length anchoring bolt support effect is better. The surrounding rock in the end anchoring zone and the full-length anchoring zone began to deform significantly at 200 m and 150 m from the working face, respectively. This indicates that the control effect of the full-length anchoring bolt support is better and verifies the rationality of the surrounding rock stability index to describe the instability characteristics. This research method can provide a theoretical reference for analysis of the stability characteristics and support design of different cross-section roadways.


2018 ◽  
Vol 175 ◽  
pp. 04016
Author(s):  
NIU Yan ◽  
Ji Yafei ◽  
Wang Zhao

Tunnel excavation will lead to the immediate surrounding rock unloading caused by the surrounding rock stress release, the stability of the surrounding rock have a certain impact. In this paper, finite element software ANSYS and finite difference software FLAC3D are used to simulate the excavation and lining process of circular tunnel. The influence of excavation on the rock stability around circular tunnel is analyzed, and the effect of applying lining on the stability of surrounding rock is analyzed. Evaluation criteria selection hole displacement, stress and plastic area of three factors.


2013 ◽  
Vol 353-356 ◽  
pp. 398-402
Author(s):  
Xiao Yu Zhang ◽  
Feng Ming Liu ◽  
Gang Chen

The initial stress of rock is a basic parameter, which can be used for surrounding rock stability analysis, exploitation and support design. By utilizing stress relief method of hollow inclusion with its characters of high precision and obtaining three dimensional stress at one time, we have measured three dimensional stress magnitude and direction in north wing roadway (-850m) and 710 open-off cut (-1000m), respectively. The results show that the horizontal tectonic stress is obvious in this coal area.


2011 ◽  
Vol 90-93 ◽  
pp. 1900-1903
Author(s):  
Fu Ming Wang ◽  
Xiao Long Li ◽  
Yan Hui Zhong ◽  
Xiao Guang Chen

Taking Chaijiazhuang Tunnel of Lingnan Expressway as project background, the stability analysis of surrounding rock was performed based on the coupled fluid-solid theory. The distributions of stress field, displacement field and plastic zone of rock mass after excavation of tunnel were discussed considering coupled effect between flow and stress under the condition of different rock level and tunnel depth. Compared with the calculation results of not considering coupling effect, the maximum deformation, maximum principle stress and plastic zone size of wall rock were obviously increased when considering coupling effect, which showed a remarkable influence of coupled fluid-solid effect on the stability of tunnel surrounding rock. Some conclusions were drawn and may provide some guidance to the design and construction of tunnels in water-rich strata.


Sign in / Sign up

Export Citation Format

Share Document