scholarly journals Large Deformation Characteristics of Surrounding Rock and Support Technology of Shallow-Buried Soft Rock Roadway: A Case Study

2022 ◽  
Vol 12 (2) ◽  
pp. 687
Author(s):  
Liu Zhu ◽  
Qiangling Yao ◽  
Qiang Xu ◽  
Liqiang Yu ◽  
Qundi Qu
Keyword(s):  
Bearing Capacity ◽  
Soft Rock ◽  
Site Investigation ◽  
Surrounding Rock ◽  
Numerical Calculations ◽  
Deformation Characteristics ◽  
Damage Characteristics ◽  
Support Resistance ◽  
Soft Rock Roadway ◽  
Rock Roadway

The coal resources in the coal-rich area of western China are mostly located in the late diagenetic Cretaceous and Jurassic strata. In this paper, a study on the support of soft rock roadways was carried out in the background of the soft rock track roadway in the Jiebangou coal mine. The field investigation showed that the surrounding rocks of the roadway were weak, soft, and broken, and the surrounding rocks were cemented, with the roadway local deformation exceeding 1 m. The borehole television results showed that the surrounding rocks were mainly weak sandy mudstone and yellow mudstone. The average uniaxial compressive strength of the surrounding rock was 15.49 MPa. The roadway is a shallow buried soft rock roadway; site investigation revealed that the original U-shaped steel shed had an extremely low resistance to slip, the filling body behind the U-shaped steel shed fell off, the interaction between the U-shaped steel shed and the surrounding rock was poor, the U-shaped steel shed could not provide sufficient timely support resistance, and the bearing capacity of the U-shaped steel shed was far from consideration. The floor was not effectively supported. The floor had different degrees of the bottom drum, and frequent undercover caused new stress disturbances, which loosened the bottom corners of both rock types and made the shed legs move continuously inward, reducing the bearing capacity and actual support resistance of the bracket. Numerical calculations were performed to study the deformation characteristics of the surrounding rock of the tunnel and the yielding damage characteristics of the brace. The results showed that the current U-shack support strength was insufficient, the two sides were deformed by 950 mm, the bottom of the roadway bulged by 540 mm, and the surrounding rock was mainly shear damaged. The fall of the filler behind the shed caused damage to the U-shaped steel shed spire. Through site investigation results and numerical calculations, the deformation and damage characteristics of the soft rock roadway and its damage causes were analyzed, and the support technology system of ‘strengthening support for weak structural parts’ was proposed. This improved the mechanical properties of the weak structural support body, the stress state of the local surrounding rock, and the bearing capacity of the support structure, and effectively controlled the deformation, damage, and instability of the surrounding rock of the roadway, and deformation, damage, and destabilization of the roadway, thereby achieving overall stability for the surrounding rock of the roadway.

Strength Assessments of Concrete-Filled Steel Tubular Support of Soft Rock Roadway

2013 ◽  
Vol 838-841 ◽  
pp. 1884-1890 ◽  
Author(s):  
Guang Long Qu ◽  
Yan Fa Gao ◽  
Liu Yang ◽  
Bin Jing Xu ◽  
Guo Lei Liu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Flexural Performance ◽  
Laboratory Test Results ◽  
Different Types ◽  
Soft Rock Roadway ◽  
Core Concrete ◽  
Rock Roadway

Compared with I-shaped and U-shaped supports in soft rock roadway, concrete-filled steel tubular (CFST) support, as a new supporting form, has stronger bearing capacity with reasonable price. So it is becoming more and more popular in roadway supporting of coal mine in China. In this article, the surrounding rock in soft rock roadway was classified into three different types: hard rock in deep coal mine, soft surrounding rock, extremely soft surrounding rock. And, according to the characteristics of deformation failure of the CFST support and the surrounding rock in the industrial tests, three different strength assessments, including assessment of axial compressive strength, assessment of lateral flexural performance, assessment of hardening rate of core concrete, were proposed through mechanical analysis and laboratory tests for the three different types of the surrounding rock, respectively. Moreover, aimed to insufficient flexural strength of the support or low hardening rate of the core concrete in some of the roadway supporting, strengthening lateral flexural performance or making early strength concrete was necessary for the above unfavorable situations. The laboratory test results showed that the ultimate bearing capacity for the CFST support with φ194*8mm of steel tube reinforced by φ38mm round steel was 31% greater than that of the unreinforced one, 177% greater than that of the U-shaped one with equivalent weight per unit length.

Deformation characteristics of surrounding rock of broken and soft rock roadway

2009 ◽  
Vol 19 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Jin-xi WANG ◽  
Ming-yue LIN ◽  
Duan-xin TIAN ◽  
Cun-liang ZHAO
Keyword(s):  
Soft Rock ◽  
Surrounding Rock ◽  
Deformation Characteristics ◽  
Soft Rock Roadway ◽  
Rock Roadway

Study on Surrounding Rock Deformation Characteristics and Control Technology in Deep Soft Rock Roadway

2012 ◽  
Vol 594-597 ◽  
pp. 631-635 ◽  
Author(s):  
Wen Hua Zha ◽  
Xin Zhu Hua
Keyword(s):  
Soft Rock ◽  
Surrounding Rock ◽  
Control Technology ◽  
Deformation Characteristics ◽  
Control Effect ◽  
Tunnel Support ◽  
Technical Problems ◽  
Geological Conditions ◽  
Soft Rock Roadway ◽  
Rock Roadway

To explore support technical problems in deep soft rock roadway, according to deep complicated geological conditions in 102 transport rise of Yuandian Mine, obtaining deformation characteristics of roadway in the initial support scheme under conditions, analysing the reasons of instability and failure of surrounding rock, proposing the surrounding rock control technology of step-by-step strengthen co-supporting, determining secondary anchor cable strengthen support time and grouting delay distance, optimizing the parameters of roadway support. Industrial practice show that the control effect of deformation was obvious,which provide the reference for deep soft rock tunnel support decision.

scholarly journals Deformation Mechanism and Support Technology of Deep and High-Stress Soft Rock Roadway

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Lujing Zheng ◽  
Yujun Zuo ◽  
Yafei Hu ◽  
Wei Wu
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
High Stress ◽  
Soft Rock ◽  
Physical And Mechanical Properties ◽  
Surrounding Rock ◽  
Rock Fragmentation ◽  
The Stability ◽  
Soft Rock Roadway ◽  
Rock Roadway

In this study, the analysis and control of stability of surrounding rock in deep fractured soft rock roadway located in the underground mine of Jinfeng gold mine in Guizhou Province, China, has been investigated. The surrounding rock of roadway has been analyzed to characterize its deformation and failure mechanism through field survey, testing of rock physical and mechanical properties, in situ stress measure, analysis of mineral components of rock, and investigation of rock fragmentation degree. Based on the numerical simulation technology, the influence of different factors on the stability of roadway is studied. The physical and mechanical properties of surrounding rock and the bearing capacity of surrounding rock layer are to be improved to maintain the stability of broken soft rock roadway as high ground stress, rock fragmentation, and poor lithology leading to tunnel instability. Hence, a high-strength “cable bolt + fiber-reinforced shotcrete + steel mesh + split sets + resin bolt + cement grouting” combined support system has been proposed to improve the effective bearing structure significantly with high integrity and bearing capacity.

Study on the Application of Bolt-Grout Reinforcement in the Deep Soft Rock Roadway

2011 ◽  
Vol 90-93 ◽  
pp. 1956-1959 ◽  
Author(s):  
Zhi Lin Dun ◽  
Da Shuai Ren ◽  
Lian Wei Ren
Keyword(s):  
Soft Rock ◽  
Field Monitoring ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Mining Depth ◽  
Air Inlet ◽  
Strata Behavior ◽  
Soft Rock Roadway ◽  
Two Sides ◽  
Rock Roadway

With the increasement of mining depth, the strata behavior of the roadway is obvious. As the stress of surrounding rock increases, the bottom of the soft rock roadway becomes deformed easily compressed by its top rock and two sides rock, which leads to the occurrence of the pucking and roadway destruction. Aiming the air inlet roadway destruction phenomenon of -450th level powder magazine in Hebi Zhongtai Mining Co.Ltd, the geological condition and the mechanism of the roadway failure are analysed comprehensively, and the bolt-grout supporting method is also proposed in this paper. At last, the deformation and heaving floor are controlled effectively which is proved by the field monitoring results.

Numerical Simulation of Bolt-Mesh-Anchor Support Technology at Soft Rock Roadway

2013 ◽  
Vol 868 ◽  
pp. 251-254 ◽  
Author(s):  
Hui Yu ◽  
Ling Gen Kong ◽  
Zhi Yong Niu ◽  
Shi Ting Zhu ◽  
Dan Yang Jing
Keyword(s):  
Simulation Analysis ◽  
Soft Rock ◽  
Confining Pressure ◽  
Surrounding Rock ◽  
Numerical Software ◽  
The Stability ◽  
Roadway Deformation ◽  
Soft Rock Roadway ◽  
Surrounding Rock Stress ◽  
Rock Roadway

The roof of 12501 transportation roadway of Tunlan mine is friable. To solve the problem of large roadway deformation, the bolt-mesh-anchor support scheme is put forward. With the FLAC3D numerical software in the program, the simulation analysis shows that the program can effectively increase the roadway confining pressure to improve the state of the surrounding rock stress, reduce roadway displacement and deformation and thus keep the stability of the surrounding rock. The results show that Bolt and cable support can effectively control the surrounding rock, with the roadway convergence rate small, and the support system safe.

scholarly journals Study on bearing capacity characteristics of steel structure support in soft rock roadway

2021 ◽  
Author(s):  
Ya‐bin Wu ◽  
Jian‐hua Hu ◽  
Xu‐yang Zhang ◽  
Ya‐guang Qin ◽  
Zhi‐bo Zhang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Soft Rock ◽  
Steel Structure ◽  
Soft Rock Roadway ◽  
Rock Roadway

scholarly journals Study on Surrounding Rock-Bearing Structure and Associated Control Mechanism of Deep Soft Rock Roadway Under Dynamic Pressure

2019 ◽  
Vol 11 (7) ◽  
pp. 1892 ◽  
Author(s):  
Dongdong Qin ◽  
Xufeng Wang ◽  
Dongsheng Zhang ◽  
Xuyang Chen
Keyword(s):  
Dynamic Pressure ◽  
Soft Rock ◽  
Friction Angle ◽  
Surrounding Rock ◽  
Control Effect ◽  
Pressure Relief ◽  
Reinforcement Scheme ◽  
Soft Rock Roadway ◽  
Bearing Structure ◽  
Rock Roadway

Providing support for deep soft rock roadways under dynamic pressure is a major technical challenge. In this study, the distribution characteristics of surrounding rock-bearing structure of such roadways were systematically examined using theoretical analysis and numerical simulation. Based on the control effect of different support methods on the surrounding rock-bearing structure; a reinforcement scheme for deep dynamic soft rock roadway was proposed and applied. The results indicate that: (1) by increasing the supporting strength of the internal bearing structure, cohesion, and internal friction angle of the surrounding rock, and by reducing the influence of mining, making the external bearing structure close to the roadway and reducing the thickness of the bearing structure, can improve the bearing capacity of the shallow surrounding rock in the roadway; (2) under the conditions of dynamic load and creep of the surrounding rock; the deformation of the rock increases significantly; external bearing structure is far away from the roadway, and thickness of the bearing structure increases; anchor cable support and floor pressure relief effect better control over the roof and the roadside deformation and floor heave, respectively; and the thickness of the corresponding external bearing structure is reduced by 30.84% and 41.50%, respectively; and (3) based on the application, the zonal reinforcement scheme of “fix cable to shed, floor pressure relief, deep-shallow composite grouting” is proposed and put into practice, with good results. The results of this study can provide theoretical support and reference for the determination of supporting parameters in deep roadways.

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