Research on Large Deformation Control Measures of Surrounding Rock in Jointed and Altered Granite Stratum of High Ground Stress Tunnel

2021 ◽  
pp. 15-28
Author(s):  
Xinghua Fang ◽  
Junsheng Yang ◽  
Xuemin Zhang ◽  
Linyi Li ◽  
Weilong Liu
Keyword(s):  
Large Deformation ◽  
Surrounding Rock ◽  
Control Measures ◽  
Deformation Control ◽  
Altered Granite ◽  
Ground Stress

scholarly journals Field Tests and research of Large Deformation Control Measures for Soft Rock Tunnel with High Geostress

2020 ◽  
Vol 570 ◽  
pp. 042006
Author(s):  
Xiaoming Sun ◽  
Bo Zhang ◽  
Yong Zhang ◽  
Xiaobing Qiao ◽  
Zhijiao Wang ◽  
...  
Keyword(s):  
Large Deformation ◽  
Field Tests ◽  
Soft Rock ◽  
Control Measures ◽  
Deformation Control ◽  
High Geostress ◽  
Rock Tunnel

scholarly journals Study on large deformation characteristics and control technology of tunnel surrounding rock in debris flow accumulation area

2021 ◽  
Vol 233 ◽  
pp. 03004
Author(s):  
Mu-shui Lin ◽  
Cheng-ke Zhang ◽  
Rong-jun Wu ◽  
Fu-sheng Qiu ◽  
Ning Li ◽  
...  
Keyword(s):  
Debris Flow ◽  
Large Deformation ◽  
Ground Surface ◽  
Surrounding Rock ◽  
Control Measures ◽  
Control Technology ◽  
Deformation Characteristics ◽  
Flow Area ◽  
Surface Stability ◽  
Flow Accumulation

Debris flow accumulation has the characteristics of loose and broken, low strength, poor stability and so on. When the tunnel passes through the debris flow accumulation area, it is easy to bring major safety hazards to the construction site. Based on the engineering background of Gangou tunnel crossing debris flow accumulation area in the fourth bid of Jiumian expressway, this paper establishes a numerical calculation model, studies the large deformation characteristics of tunnel surrounding rock in debris flow area, determines the reasonable reinforcement range of tunnel surrounding rock, and puts forward the comprehensive control technology of tunnel passing through debris flow accumulation body combining surface stability and underground reinforcement based on simulation results and field experience. The numerical results show that the deformation of surrounding rock and ground surface can be effectively controlled. The rationality of the proposed control measures is verified by field monitoring, which provides a reference for surrounding rock control of tunnel under type conditions.

scholarly journals Directionality of butterfly leaves and nonuniform deformation mechanism in gob-side entry driving roadway

2021 ◽  
Vol 37 ◽  
pp. 291-301
Author(s):  
Ji Li ◽  
Wenshuo Wang ◽  
Bin Li ◽  
Jihao Tan ◽  
Bo Peng
Keyword(s):  
Plastic Zone ◽  
Large Deformation ◽  
Deformation Mechanism ◽  
Plastic Region ◽  
Central Area ◽  
Surrounding Rock ◽  
Deformation And Failure ◽  
Main Stress ◽  
Combined Action ◽  
Ground Stress

ABSTRACT Existing rock pressure theory, with the pressure-plastic zone as the core, cannot reveal the nonuniform large deformation mechanism of the surrounding rock in a deep roadway. To address this problem, the 11030 gob-side entry driving roadway of the Zhaogu No. 2 Mine is used as an example, in conjunction with elastoplastic mechanics theoretical analysis, to study the butterfly plastic region and the direction of the butterfly leaf in the homogeneous circular roadway. In addition, the finite-element method was used to study the environmental characteristics of the stress field of the surrounding rock before the excavation of the gob-side entry driving roadway and to analyze the effect of the principal stress on the butterfly plastic region of the surrounding rock. The results showed that, under the combined action of high ground stress and disturbed stress, the surrounding rock of the deep front edge of the gob in the central area of the main stress could form a large range for the butterfly leaf plastic area. The deflection angle of the four butterfly leaves in the plastic region was the same as that of the main stress direction. The butterfly plate plastic zone that formed in the deep surrounding rock of the gob-side entry driving roadway led to not only extension, degradation and disappearance to different degrees, but also deflection under the action of the main stress. This led to large deformation of the rock strata in the butterfly leaf plastic region, ultimately causing uneven deformation and failure of the 11030 roadway.

Numerical Analysis on Loading History Correlation for Large Deformation Control within Deep Soft Rock

2012 ◽  
Vol 594-597 ◽  
pp. 585-588
Author(s):  
Yue Yuan ◽  
Xu Chun Wang ◽  
Xin Liu
Keyword(s):  
Large Deformation ◽  
Mechanical Response ◽  
Mechanical Design ◽  
Design Method ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Construction Process ◽  
Loading History ◽  
Construction Sequence ◽  
Deformation Control

The correlation of the load history in the nonlinear large deformation mechanical design method is discussed. Then the different schemes of support construction process which are used to control the nonlinear large deformation of the east wing main haulage roadway in -1000m level of a certain coal mine are simulated by the program of 3D finite difference. The results show that the deformation results, the displacement distribution characteristics and the stress concentration degree of surrounding rock are significantly different due to the different construction sequence. After plastic large deformation occurs in deep soft rock ,the mechanical response characteristics of the surrounding rock closely related to the entire loading history. And different construction sequence will produce different deformation control effect. Therefore, the use of large deformation mechanical design method for the supporting design of deep soft rock is necessary, then based on the proposing of the mechanical countermeasures the best construction process is determined, and the optimization of support parameters must be for this process.

Research Situation of Large Deformation Mechanism and Prevention-Control Measures of Surrounding Rock in Tunnel

2013 ◽  
Vol 671-674 ◽  
pp. 1160-1165
Author(s):  
Liang Qin Tang ◽  
Ya Jun Zang ◽  
Kui Tang
Keyword(s):  
Large Deformation ◽  
Surface Engineering ◽  
Great Difficulty ◽  
Surrounding Rock ◽  
Control Measures ◽  
Tunnel Construction ◽  
Prevention Measure ◽  
Large Distortion ◽  
Research Situation ◽  
Design Construction

The tunnel and the understructure works are excavated in the rock or the soil. In comparison with surface engineering, design construction and maintenance of understructure works are more complicated. Especially, after the underground rock or soil is excavated, the large deformation which generated by the crustal stress field change, will bring the great difficulty for supports and protections of surrounding rock. Based on this fact, this paper introduces the current research of formation mechanism of surrounding-rock large distortion that was met in the construction and operation of the tunnel and understructure works, and the prevention measure that was adopted at home and abroad currently. New knowledge is acquired through study; this will draw very useful reference to deeply-buried long tunnel construction in the future.

Research on construction method and deformation control technology of high ground stress interbedded soft rock tunnel

2020 ◽  
pp. 1-9
Author(s):  
Zhichun Fang ◽  
Zhengguo Zhu ◽  
Xinyu Chen
Keyword(s):  
Numerical Models ◽  
Soft Rock ◽  
Construction Method ◽  
Gansu Province ◽  
Control Measures ◽  
Deformation Characteristics ◽  
Deformation Control ◽  
Geological Conditions ◽  
Ground Stress ◽  
Rock Tunnels

The construction of tunnels is often long and deep buried tunnels, and the geological conditions are more complex. Based on Jianshan tunnel in Gansu Province, the special geological conditions such as high ground stress and weak interbedded surrounding rock make the excavation of tunnel easy to produce large deformation. In this article, the software finite difference software FLAC3D was used to establish numerical models and select the best construction method by comparing the deformation of the tunnel under different construction methods. Aiming at the deformation characteristics of soft rock tunnels in highland interbedded layers, the control measures of tunnel deformation are discussed. Mainly consider the two aspects of the bolt support plan and the second lining construction time, comprehensively compare the deformation characteristics of the tunnel, and select the best working condition. The research results show that the combination of three-step temporary invert method and three-step ultra short bench method is recommended for the tunnel construction; when the bench length is 4 m, the deformation control effect of the tunnel is the best; by improving the length and angle of the anchor rod, the deformation of the tunnel can also be well controlled.

scholarly journals Analysis of Tunnel Water Inrush Considering the Influence of Surrounding Rock Permeability Coefficient by Excavation Disturbance and Ground Stress

2021 ◽  
Vol 11 (8) ◽  
pp. 3645
Author(s):  
Helin Fu ◽  
Pengtao An ◽  
Long Chen ◽  
Guowen Cheng ◽  
Jie Li ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Water Pressure ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Water Inflow ◽  
Calculation Error ◽  
External Water Pressure ◽  
Ground Stress ◽  
External Water ◽  
Inflow Prediction

Affected by the coupling of excavation disturbance and ground stress, the heterogeneity of surrounding rock is very common. Presently, treating the permeability coefficient as a fixed value will reduce the prediction accuracy of the water inflow and the external water pressure of the structure, leading to distortion of the prediction results. Aiming at this problem, this paper calculates and analyzes tunnel water inflow when considering the heterogeneity of permeability coefficient of surrounding rock using a theoretical analysis method, and compares with field data, and verifies the rationality of the formula. The research shows that, when the influence of excavation disturbance and ground stress on the permeability coefficient of surrounding rock is ignored, the calculated value of the external water force of the tunnel structure is too small, and the durability and stability of the tunnel are reduced, which is detrimental to the safety of the structure. Considering the heterogeneity of surrounding rock, the calculation error of water inflow can be reduced from 27.3% to 13.2%, which improves the accuracy of water inflow prediction to a certain extent.

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