scholarly journals Evolution Mechanism and Stability Analysis of Roof Deflection of Composite Structure Roadway Under Dynamic Load Disturbance

2021 ◽  
Author(s):  
Zequan Sun ◽  
Hao Feng ◽  
Wenhai Wang ◽  
Tao Guo ◽  
Qingwei Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Dynamic Load ◽  
Composite Structures ◽  
Surrounding Rock ◽  
Model Group ◽  
Rock Stability ◽  
The Stability ◽  
Center Deflection ◽  
Hard Type

Abstract The lithology of the roof of the mining roadway is compound and the thickness of each layer varies greatly, and it is disturbed by dynamic load all the year round. The above factors have caused a huge difference in the stability of the roadway surrounding rock. Taking the 11020 lower tunnel of a mine in Henan Province as the engineering geological background, using on-site investigation, formula derivation, numerical simulation and other methods, the composite roof roadway model group was established to study the deflection evolution characteristics of the surrounding rock under dynamic load disturbance, and summarize the plastic zone of the surrounding rock of the roadway Deformation and evolution of roof surrounding rock to evaluate the stability of surrounding rock with different roof structures. The research results show that the change of the roof surrounding rock structure will also lead to the change of the center deflection of the roadway roof. Therefore, the center deflection of the surrounding rock of various roof composite structures is different, and the deflection is the most direct indicator of the stability of the surrounding rock. The center deflection (ω0) of the soft rock type is the largest, the center deflection (ω0) of the upper soft and the lower hard type, and the soft and hard type is larger, and the soft and hard progressive type, thin, hard and thick soft type (ω0) is the smallest, and the dynamic load The relationship between the magnitude of deflection before and after the disturbance is consistent. By constructing a composite roof roadway numerical model group, By constructing a composite roof roadway numerical model group, using the plastic failure zone of the roadway as the evaluation standard, the surrounding rock stability is evaluated and divided, and then the cross-point field measurement method is used to verify the stability of the surrounding rock on the roof of different composite structures. And the development of composite roof roadway surrounding rock deformation and failure mechanism and numerical simulation method has important theoretical significance and practical value for the analysis and control of composite roof roadway surrounding rock stability.

Application of ABAQUS in Surrounding Rock Stability Analysis of Shallow Large Cross-Section Tunnel

2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strong Support ◽  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
Rock Bolting ◽  
Excavation Support ◽  
The Stability

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.

Stability Analysis of Tunnel during the Excavation Based on ANSYS

2014 ◽  
Vol 577 ◽  
pp. 1135-1138
Author(s):  
Bing He ◽  
Guang Zhi Yin
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Stress Condition ◽  
Stability Control ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Rock Stability ◽  
Before And After ◽  
The Stability

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.

scholarly journals Study on instability failure mode and monitoring early warning standard of surrounding rock in fully weathered argillaceous sandstone section of large section tunnel

2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua
Keyword(s):  
Limit State ◽  
Stable State ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Large Section ◽  
Rock Stability ◽  
Geological Conditions ◽  
Construction Step ◽  
The Face ◽  
The Stability

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.

scholarly journals Surrounding Rock Movement of Steeply Dipping Coal Seam Using Backfill Mining

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Wenyu Lv ◽  
Kai Guo ◽  
Jianhao Yu ◽  
Xufeng Du ◽  
Kun Feng
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Surrounding Rock ◽  
Maximum Deflection ◽  
Coal Seams ◽  
Physical Similarity ◽  
Working Face ◽  
Rock Structure ◽  
Backfill Mining ◽  
The Stability

The movement of the overlying strata in steeply dipping coal seams is complex, and the deformation of roof rock beam is obvious. In general, the backfill mining method can improve the stability of the surrounding rock effectively. In this study, the 645 working face of the tested mine is used as a prototype to establish the mechanical model of the inclined roof beam using the sloping flexible shield support backfilling method in a steeply dipping coal seam, and the deflection equation is derived to obtain the roof damage structure and the maximum deflection position of the roof beam. Finally, numerical simulation and physical similarity simulation experiments are carried out to study the stability of the surrounding rock structure under backfilling mining in steeply dipping coal seams. The results show the following: (1) With the support of the gangue filling body, the inclined roof beam has smaller roof subsidence, and the maximum deflection position moves to the upper part of working face. (2) With the increase of the stope height, the stress and displacement field of the surrounding rock using the backfilling method show an asymmetrical distribution, the movement, deformation, and failure increase slowly, and the increase of the strain is relatively stable. Compared with the caving method, the range and degree of the surrounding rock disturbed by the mining stress are lower. The results of numerical simulation and physical similarity simulation experiment are generally consistent with the theoretically derived results. Overall, this study can provide theoretical basis for the safe and efficient production of steeply dipping coal seams.

scholarly journals Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jucai Chang ◽  
Kai He ◽  
Zhiqiang Yin ◽  
Wanfeng Li ◽  
Shihui Li ◽  
...  
Keyword(s):  
Coal Mine ◽  
Stability Index ◽  
Surrounding Rock ◽  
Full Length ◽  
Control Effect ◽  
Support Design ◽  
Rock Stability ◽  
Working Face ◽  
The Stability ◽  
Bolt Support

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.

scholarly journals Study on Stability of Round Tunnel Surrounding Rock

2018 ◽  
Vol 175 ◽  
pp. 04016
Author(s):  
NIU Yan ◽  
Ji Yafei ◽  
Wang Zhao
Keyword(s):  
Evaluation Criteria ◽  
Surrounding Rock ◽  
Rock Stress ◽  
Stress Release ◽  
Circular Tunnel ◽  
Tunnel Excavation ◽  
Finite Element Software ◽  
Rock Stability ◽  
The Stability ◽  
Surrounding Rock Stress

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.

Numerical Simulation on Supporting of Deep Surrounding Rock with Zonal Disintegration Tendency

2013 ◽  
Vol 671-674 ◽  
pp. 230-234
Author(s):  
Yu Jun Zuo ◽  
De Kang Zhu ◽  
Wan Cheng Zhu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Surrounding Rock ◽  
Zonal Disintegration ◽  
Finite Element Software ◽  
Stability Of Surrounding Rock ◽  
Ground Stress ◽  
Zonal Disintegration Phenomenon ◽  
The Stability ◽  
The Zonal Disintegration Phenomenon

In order to study the supporting of deep surrounding rock with zonal disintegration tendency, the zonal disintegration phenomenon of deep surrounding rock under three supporting forms is analyzed by the ABAQUS finite element software in this paper, and three supporting forms are un-supporting, bolting and grouting, and combined “Bolting and grouting plus Anchor rope” supporting. The results show that the different effects to zonal disintegration under different supporting forms will occur. Supporting can help to restrain the zonal disintegration of the reinforcement part advantageously, and also lower rupture degree of zonal disintegration and reduce the size of rupture zone. Meanwhile, the stability of surrounding rock is improved. But zonal disintegration may occur outside reinforcement part under greater ground stress. The results are great importance to a better understanding of the deep roadway supporting.

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
Keyword(s):  
Stability Analysis ◽  
Rough Set ◽  
Ideal Point ◽  
Surrounding Rock ◽  
Ideal Solution ◽  
Rock Stability ◽  
The Stability ◽  
Efficacy Coefficient Method ◽  
Coefficient Method ◽  
The Ideal

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.

scholarly journals Numerical simulation of cutting layer in internal corners milling

Mechanik ◽  
2019 ◽  
Vol 92 (7) ◽  
pp. 412-414
Author(s):  
Jan Burek ◽  
Rafał Flejszar ◽  
Barbara Jamuła
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Cross Section ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
The Cross ◽  
The Stability

The analytical and numerical model of the cross-section of the machined layer in the process of milling of concave rounding is presented. Simulation tests were carried out to determine the cross-sectional area of the cutting layer. A strategy has been developed that allows to increase the stability of the cross-section area of the cutting layer when the mill enters the inner corner area.

Displacement Back Analysis Research on Bolt-Grouting Supporting Parameter of Rock Mass in Jointed Rock Roadway

2004 ◽  
Vol 261-263 ◽  
pp. 1563-1568
Author(s):  
Le Wen Zhang ◽  
Shu Chen Li ◽  
Shu Cai Li
Keyword(s):  
Rock Mass ◽  
Mass Parameter ◽  
Back Analysis ◽  
Jointed Rock ◽  
Singular Value ◽  
Surrounding Rock ◽  
Elastic Model ◽  
Rock Stability ◽  
The Stability ◽  
Rock Roadway

The method of bolt-grouting supporting, grouting into surrounding rock mass by bolts in jointed rock mass roadway, is obtained wide application. However, it is difficult to determine rock mass parameter of bolt-grouting supporting. This paper begins with the displacement, which is measured easily in practice. The method of back analysis is adopted to calculate the equivalent mechanics parameters of bolt-grouting rock mass. In process of back analysis three mechanics models is supposed which are homogeneous elastic model, inhomogeneous elastic model and elastic-plastic model and corresponding algorithm is established. What's more, this paper discusses the stability of inverse algorithm and copes the problem of back analysis parameter probably instable with QR decomposed algorithm and singular value decomposed algorithm, which will be a theoretical base to determine the mechanics parameter of bolt-grouting supporting rock mass and to estimate the surrounding rock stability. In a word, the method is established to estimate mechanics parameters of bolt-grouting jointed surrounding rock mass, and some significant results are obtained, which are of reference for actual project.

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