# Study on Overburden Movement Deformation and Roof Breakage Law of Under-Protective Steeply Inclined Coal Seam Mining

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## Abstract

**:**

## 1. Introduction

## 2. Roof Breaking Regular of Under-Protective Steeply Inclined Coal Seam Mining

#### 2.1. Stress Analysis of Steep Roof

#### 2.2. Analysis of the First Roof Collapse with the Thin-Plate Theory

^{3}; $\lambda $ is the side pressure coefficient, $\lambda =\frac{{\mu}^{\prime}}{1-{\mu}^{\prime}}$, with ${\mu}^{\prime}$ as Poisson’s ratio, taken as 0.24, and the calculated $\lambda $ is 0.316; $\alpha $ is the coal seam inclination, 50°.

^{4}MPa; ${\mu}^{\prime}$ is Poisson’s ratio, taken as 0.24; h is the thickness of the main roof strata participating in the incoming pressure, 4 m; A is the roof exposed area, A = a × b, m

^{2}.

#### 2.3. Analysis in Normal Mining Stage with the Thin-Plate Theory

_{k}of gangue filling, and the effect of the gangue filling foundation can be considered the elastic foundation.

## 3. Similar Simulation Experiment of Overburden Movement Deformation of Under-Protective Steeply Inclined Coal Seam Mining

#### 3.1. Experimental Model Design

#### 3.2. Experimental Procedure

- (1)
- Lay the model

- (2)
- Layout of rock stratum mobile measuring points

- (3)
- Compensate stress

- (4)
- Excavation and data collection

#### 3.3. Experimental Results

## 4. Analysis and Discussion

## 5. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 3.**The calculation model of the roof initial breaking down. (

**a**) The side view. (

**b**) The top view.

**Figure 5.**Calculation model of the roof caving in normal mining phase. (

**a**) The side view. (

**b**) The top view.

**Figure 8.**The panorama of modeling experiment. (

**a**) The front side of the model. (

**b**) The back of the model.

**Figure 9.**The comparison chart of strata movement. (

**a**) The first collapse. (

**b**) The second collapse. (

**c**) The third collapse. (

**d**) End of the mining.

The Type of Plate | The Thin Films | The Thin Plate | The Thick Plate |
---|---|---|---|

The ratio of thickness (δ) to minimum side length (b) | $\frac{\delta}{b}<(\frac{1}{100}~\frac{1}{80})$ | $(\frac{1}{100}~\frac{1}{80})\le \frac{\delta}{b}\le (\frac{1}{8}~\frac{1}{5})$ | $\frac{\delta}{b}>(\frac{1}{8}~\frac{1}{5})$ |

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**MDPI and ACS Style**

Peng, X.; Qi, L.; Wang, Z.; Zhou, X.; Hua, C.
Study on Overburden Movement Deformation and Roof Breakage Law of Under-Protective Steeply Inclined Coal Seam Mining. *Sustainability* **2022**, *14*, 10068.
https://doi.org/10.3390/su141610068

**AMA Style**

Peng X, Qi L, Wang Z, Zhou X, Hua C.
Study on Overburden Movement Deformation and Roof Breakage Law of Under-Protective Steeply Inclined Coal Seam Mining. *Sustainability*. 2022; 14(16):10068.
https://doi.org/10.3390/su141610068

**Chicago/Turabian Style**

Peng, Xinshan, Lingling Qi, Zhaofeng Wang, Xiaoqing Zhou, and Chunlei Hua.
2022. "Study on Overburden Movement Deformation and Roof Breakage Law of Under-Protective Steeply Inclined Coal Seam Mining" *Sustainability* 14, no. 16: 10068.
https://doi.org/10.3390/su141610068