Design and Field Test of Bolt-Mesh-Cable Support of Extraction Drift in Soft Thick Seam with a Large Angle

2011 ◽  
Vol 243-249 ◽  
pp. 3565-3571
Author(s):  
Dong Ming Guo ◽  
Jing Zhao Zhuang ◽  
Yi Zhang ◽  
Yan Bin Wang ◽  
Ren Shu Yang
Keyword(s):  
Large Angle ◽  
Support Effect ◽  
Surrounding Rock ◽  
Surface Load ◽  
Thick Seam ◽  
Rock Stability ◽  
Ground Pressure ◽  
Geological Conditions ◽  
Stability Classification ◽  
Bolt Support

Considering the poor support results of extraction drift in soft thick seam with a large angle in Dujiacun Mine, and there’s no similar design in such engineering geological conditions. Firstly, determined surrounding rock stability classification of the drift and obtained that roadway surrounding rock of this mine is type. According to the approximate range of this type roadway surrounding rock, selected parameters of bolt support, then using FLAC3Dsoftware simulated support effect of the roadway with different parameters of bolt support, analyzed the extent of the support effect of various parameters. The simulation results show that the optimal program is φ2200mm round steel bolt in the roof andφ2500mm equal strength thread steel in the two sides. Monitoring results of ground pressure displacement of surface, load of bolt and amount of roof separation show that bolt-mesh-cable support is safe and effective.

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 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 and Application on Stability Classification of Tunnel Surrounding Rock Based on Uncertainty Measure Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Hujun He ◽  
Yumei Yan ◽  
Cuixia Qu ◽  
Yue Fan
Keyword(s):  
Measure Theory ◽  
Influence Factors ◽  
Surrounding Rock ◽  
Uncertainty Measure ◽  
In Situ Data ◽  
Rock Stability ◽  
Practical Engineering ◽  
Stability Classification ◽  
Recognition Criterion

Based on uncertainty measure theory, a stability classification and order-arranging model of surrounding rock was established. Considering the practical engineering geologic condition, 5 factors that influence surrounding rock stability were taken into account and uncertainty measure function was obtained based on the in situ data. In this model, uncertainty influence factors were analyzed quantitatively and qualitatively based on the real situation; the weight of index was given based on information entropy theory; surrounding rock stability level was judged based on credible degree recognition criterion; and surrounding rock was ordered based on order-arranging criterion. Furthermore, this model was employed to evaluate 5 sections surrounding rock in Dongshan tunnel of Huainan. The results show that uncertainty measure method is reasonable and can have significance for surrounding rock stability evaluation in the future.

The Analysis of the Bolted Roadway Stability with Discrete Element Method

2011 ◽  
Vol 121-126 ◽  
pp. 1504-1508
Author(s):  
Rong Chao Wang ◽  
Chun Qiu Wang ◽  
Lei Zhang
Keyword(s):  
Surrounding Rock ◽  
Practical Application ◽  
Rock Stability ◽  
Joint Characteristics ◽  
Joint Surfaces ◽  
Roadway Stability ◽  
Geological Conditions ◽  
Horizontal Compressive Stress ◽  
Supporting Effect ◽  
Block Sizes

The model is generated in the paper taking the fully mechanized caving face in Yang-village mine, Yima group as engineering background, using UDEC software to analyze the influence of joint characteristics parameters on surrounding rock stability of fully-mechanized caving roadway, and from the aspects of the horizontal compressive stress between joint surfaces of roof, the roof sinking magnitude and surrounding rock failure, the fully-mechanized caving roadway is simulated with different anchorage forms and bolt length, with pallet and steel belt or not, different block sizes and different buried depths[1]. Through improved roadway supporting technology, the supporting effect was increased, the damage and destruction of the supporting to rock mass was reduced. The computed results were consistent with practical application. This shows that the technology has some directive significance for mining under the same geological conditions, and supports theoretical and practical basis for the mine's safety in production and sustainable development.

Optimization of Stope Structural Parameters in Phosphorite Mine and its Stability Analysis

2014 ◽  
Vol 580-583 ◽  
pp. 1268-1272 ◽  
Author(s):  
Xiang Xing Li ◽  
Ke Gang Li
Keyword(s):  
Structural Parameters ◽  
Simulation Method ◽  
Surrounding Rock ◽  
Room And Pillar Mining ◽  
Rock Stability ◽  
Mining Depth ◽  
Ground Pressure ◽  
Pillar Mining ◽  
Phosphate Deposit ◽  
The Stability

A mine plans to exploit the low dip thin phosphate deposit by room-and-pillar mining. But a township highway is just above the orebody, and its distance is only 80m, in order to better control the ground pressure in stopes and ensure the operation security, the size of room and pillar must be reasonably designed to maintain the stability of stopes and surrounding rock. The 3D-σ numerical simulation method was applied to analyze the surrounding rock stability in different stope structure parameters. The results show that when holding the size of pointed prop unchanged, the surrounding rock stability would decline with the increase of room width and pillar spacing, for security, the mining plan, the pointed prop is 3×3 m, the stope width and pillar spacing is not more than 9 m, were considered to be one of the optimal. In addition, it is important to emphasize that if the mining depth exceeds 300m, some methods, such as decreasing the spacing of stope and pointed props or increasing the pillar size, need to be taken to avoid the stope instability caused by greater ground pressure.

Monitoring and Reinforcement Technology of Passing Weak and Broken Rock Strata for Tunnel Boring Machine

2012 ◽  
Vol 204-208 ◽  
pp. 2819-2823
Author(s):  
Tao Li ◽  
Kai Bin Liu ◽  
Wei Hong Yang ◽  
Bo Liu ◽  
Ying Chao Liu
Keyword(s):  
Tunnel Boring Machine ◽  
Stability Control ◽  
Surrounding Rock ◽  
Tunnel Boring ◽  
Rock Stability ◽  
Tunnel Convergence ◽  
Geological Conditions ◽  
The Stability ◽  
Large Tunnel ◽  
Rock Strata

The stability control of surrounding rock is a relatively important problem in tunnel boring machine (TBM) construction. The tunnel convergence deformation value was monitored in field while TBM passing weak and broken section of hydraulic tunnel. The correlation between tunnel convergence and surrounding rock stability is analyzed. The monitoring results show that: the characteristic of weak and broken Strata is closely correlated with some geological conditions, such as fault development, intrusive contact of orthophyre and lamprophyre veins. These supporting measures can well ensure the stability of surrounding rock in weak and broken section, such as sealing the inverted arch by using concrete of C25,reinforcing the inverted arch by steel arch of I10 and anchor construction in the roof. There is great difference between the properties of the weak and broken rocks on both sides, which is the main reason of the large tunnel convergence deformation. The monitoring results can provide reference for similar engineering in the future.

Application of Grouting Reinforcement Technology in Pingshan Shaft Station

2014 ◽  
Vol 580-583 ◽  
pp. 1347-1351
Author(s):  
Liang Tian ◽  
Jing Yi Xi ◽  
Jian Liu ◽  
Xiao Dong Liu ◽  
Feng Shang ◽  
...  
Keyword(s):  
Roof Rock ◽  
Soft Rock ◽  
Difficult Problem ◽  
Surrounding Rock ◽  
Ground Pressure ◽  
Geological Conditions ◽  
Floor Heave ◽  
Cable Force ◽  
Grouting Reinforcement ◽  
Roadway Support

Support of soft rock is a big challenge in all mines at home and abroad. Soft rock is of different kinds of rheological property for geological conditions, mine ground pressure and so on. It brings about really difficult problem to roadway support. In order to ensure safety application and prolong usage, shaft station need to be reinforced. Sight instrument was used to analyze broken conditions. The results show that the broken depth in roof rock is 5~6 m, and greater than 4 m in sidewalls. According to failure characters and sight results, we determine that rock of shaft station belongs to high geo-stress and jointed soft rock. On this basis, technology of grouting reinforcement combined with cable anchor support is carried out. Monitoring results of surface convergence and cable force show that bearing capacity of surrounding rock increases obviously, roadway contraction and floor heave are well controlled.

The Integrated Control Countermeasures on Floor Heave of Broken Soft Rock with High Ground Stress

2014 ◽  
Vol 875-877 ◽  
pp. 2259-2263 ◽  
Author(s):  
Yao Bin Li
Keyword(s):  
Integrated Control ◽  
Soft Rock ◽  
Mining Area ◽  
Stability Control ◽  
Surrounding Rock ◽  
Deep Well ◽  
Rock Stability ◽  
Geological Conditions ◽  
Floor Heave ◽  
Key Issues

The floor heave is one of the key issues of surrounding rock stability control during the deep well mining process. To solve the problem about floor heave occupying the most of roof and floor convergence deformation, the author analyzed the engineering geological conditions of broken surrounding rock and the floor heave features in PanEr Coal Mine East 2 mining area when it through the fault zone with high pressure. It pointed out that we should make full use of the reinforcement of the roof and laneway's side to limit the deformation of the floor, and make use of overbreak, prestressed anchor cable, bottom corner bolt, deep hole grouting and backfill as direct bottom control countermeasures.

scholarly journals Surrounding Rock Stability Classification Method of Coal Roadway Based on In Situ Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yongjie Yang ◽  
Gang Huang ◽  
Lingren Meng
Keyword(s):  
Fuzzy Clustering ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
Evaluation Indexes ◽  
Rock Stability ◽  
Coal Roadway ◽  
Fuzzy Clustering Method ◽  
Stability Classification

In situ stress is one of the most important factors affecting surrounding rock stability classification of coal roadway. Most surrounding rock stability classification methods do not fully consider the influence of in situ stress. In this paper, the author applied a fuzzy clustering method to the classification of surrounding rock stability of coal roadway. Taking into account the complexity of the classification of surrounding rock, some factors such as the strength of surrounding rock, in situ stress, the main roof first weighting interval, the size of the chain pillar, and the immediate roof backfilled ratio are selected as the evaluation indexes. The weight coefficients of these evaluation indexes are determined by unary regression and multiple regression methods. Using fuzzy clustering and empirical evaluation method, the classification model of surrounding rock stability of coal roadway is proposed, which is applied to 37 coal roadways of Zibo Mining Group Ltd., China. The result is in good agreement with practical situation of surrounding rock, which proves that the fuzzy clustering method used to classify the surrounding rock in coal roadway is reasonable and effective. The present model has important guiding significance for reasonably determining the stability category of surrounding rock and supporting design of coal roadway.

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