Yield and bearing capacity of coal mine floor

1975 ◽  
Vol 12 (8) ◽  
pp. 241-253 ◽  
Author(s):  
A. Afrouz
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Mine Floor

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.

scholarly journals A Case Study on Gob-Side Entry Retaining Technology in the Deep Coal Mine of Xinjulong, China

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ping Wang ◽  
Li Ding ◽  
Yuan-jun Ma ◽  
Tao Feng ◽  
Guang-jing Sun ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Steel Tube ◽  
Actual Measurement ◽  
Deep Mining ◽  
Concrete Filled Steel Tube ◽  
Backing Plate ◽  
Anchor Cable ◽  
Working Face ◽  
Mining Face

Through the analysis of the project of gob-side entry retaining in the deep gangue filling 2305S-2# working face of the Xinjulong coal mine, the principle and technology of surrounding rock control of gob-side entry retaining along the deep mining face are discussed. It is found that the use of gangue to fill the goaf of the deep mining face can effectively alleviate the occurrence of violent strata pressure, which is the basis for realizing entry retaining along the goaf. In the Xinjulong coal mine, the gangue wall and concrete-filled steel tube columns are used as roadside support structure. Anchor bolt + W steel belt are used as advance support, monomer column + hinged beam are used as temporary support, and long anchor cable + beam are used as permanent support. Gob-side entry retaining of deep mining working face is successfully realized. The actual measurement results show that the bearing capacity of gangue wall increases slowly, and the deformation is large. The concrete-filled steel tube column has a certain drilling bottom, and the roof cable is easily broken on the side of the remaining roadway. It is necessary to strengthen the lateral constraint of the gangue wall, limit the deformation of the gangue wall, and improve the bearing capacity of the gangue wall. The bottom of the concrete-filled steel tube column needs to be installed with a large backing plate to control the bottom drilling amount, and the roof anchor cable of the roadway must have a certain elongation to realize the coordinated deformation of the anchor cable and the roof.

scholarly journals Investigation of Mechanical Properties for Group Anchors

2021 ◽  
Vol 11 (4) ◽  
pp. 1521
Author(s):  
Juncai Cao ◽  
Nong Zhang ◽  
Shanyong Wang ◽  
Qun Wei
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Design Method ◽  
Stability Control ◽  
Surrounding Rock ◽  
Physical Test ◽  
Anchor Structure ◽  
The Stability ◽  
Mine Roadways ◽  
Prestressed Anchor

Prestressed anchor support is one of the most important support methods for coal mine roadways. As the coal mining depth increases, the adaptability of existing prestressed anchor has become weaker and weaker, which is mainly reflected in the current anchor prestress is much smaller than the support resistance required for the stability of the roadways and makes it difficult to effectively control the roadways. In order to solve the problem, a group anchor structure was proposed to realize higher prestressed anchor support technology and improve the support status of deep roadways. For coal mine roadways, group anchor structure is a new technology and new topic, and the design method and theoretical basis of the group anchor support are lacking. Therefore, the paper studied the bearing capacity of the group anchors through physical tests and numerical simulations. Among them, a special set of group anchor drawing tooling was designed and processed to match the physical test. The test results show that the group anchor structure can double the bearing capacity and bearing rigidity compared with traditional anchors, and the group anchor support can further optimize the support parameters to improve the bearing capacity of the surrounding rock. Therefore, the group anchor support is helpful to the stability control of the surrounding rock of the deep roadway.

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