Skip to main content
SpringerLink
Log in

Analysis on the Breaking Law of Soft and Thick Roof of Fully Mechanized Top-Coal Caving Face

  • Original Paper
  • Published:
Geotechnical and Geological Engineering Aims and scope Submit manuscript

Abstract

The study of roof breaking law is very important for the behavior of the underground pressure in fully mechanized top-coal caving face under the condition of weak roof. In this paper, the research is to study the soft and thick roof breaking law in the fully mechanized top-coal caving face 2–100 in coal seam 2#. The theoretical analysis, numerical simulation and field measurement methods are used to analyze the breaking law of the weak thick layer roof in the fully mechanized top-coal caving face. First, the mining conditions of the working face are introduced systematically, the mechanical properties of the weak roof are analyzed, the mechanical model of the immediate roof caving structure and the mechanical model of the main roof fracture structure are established, and the instability characteristics of the immediate roof and the main roof are analyzed. Through UDEC numerical simulation, the failure structure of the soft and thick roof in fully mechanized caving face, the plastic zone and stress distribution of the roof under different propulsive lengths, and the roof subsidence of the basic roof are obtained. It is found that the immediate roof caving will form an “arch” structure, and the main roof fracture will form a “three hinge arches” structure. Under this mine condition, the initial roof caving step is 17.8 m, and the main roof initial fracture step is 41.3 m, the periodic fracture step distance is 16.7 m. Under the condition of instability of immediate roof “arch” structure, when the displacement distance of the vault reaches 5.1 m, the “arch” structure will be unstable. Conditions of sliding instability of main roof “three hinge arches” structure: the ratio of coal seam thickness to the span of main roof is less than 0.2, and when the back angle is less than 8°, it is not easy to slip and lose stability. Through the observation of the field measurement results of fully mechanized top-coal caving face 2–100, the breaking rule of the soft and thick roof in fully mechanized top-coal caving face is verified.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

References

  • Cai YQ, Geng XY (2009) Consolidation analysis of a semi-infinite transversely isotropic saturated soil under general time-varying loadings. Comput Geotech 36(3):484–492

    Article  Google Scholar 

  • Chen H, Ye Y-C et al (2020) Study on the failure form of direct roof in roadway soft layer based on rock beam-block theory. Rock and Soil Mechanics 4:1–8

    Google Scholar 

  • Cheng ZB, Zhang YN, Li LH, Lv HY (2018) Theoretical solution and analysis of the elastic modulus and foundation coefficient of coal-rock combination material. Int J Mater Sci Res 1(1):23–31

    Article  Google Scholar 

  • Cheng Z, Yang S, Li L, Zhang L (2019a) Support working resistance determined on top-coal caving face based on coal-rock combined body. Geomech Eng 19(3):255–268

    Google Scholar 

  • Cheng Z, Pan W, Li X, Sun W (2019b) Numerical simulation on strata behaviours of TCCWF influenced by coal-rock combined body. Geomech Eng 19(3):269–282

    Google Scholar 

  • Cheng ZB, Li LH, Zhang YN (2020) Laboratory investigation of the mechanical properties of coal-rock combined body. Bull Eng Geol Environ 79:1947–1958

    Article  Google Scholar 

  • Kong D, Cheng Z, Zheng S (2019) Study on failure mechanism and stability control measures in large-cutting-height coal mining face with deep-buried seam. Bull Eng Geol Env 78(8):6143–6157

    Article  Google Scholar 

  • Li G-C (2008) Study on the stability and safety control of surrounding rock in soft interlayer roof roadway. China University of Mining and Technology, Beijing

    Google Scholar 

  • Li J-W (2019) Study on breaking law and control of hard top plate in fully mechanized caving face with extra thick coal seam. Xi’an University of Science and Technology, Xi’an

    Google Scholar 

  • Li H-T, Liu C-Y, Wang L-Q (2008) The formation and instability evolution of the “loose arch” structure of the upper direct roof. J Coal Ind 04:378–381

    Google Scholar 

  • Liu X-J, Cheng Z-B (2019) Changes in subsidence-field surface movement in shallow-seam coal mining. J South Afr Inst Min Metall 119:201–206

    Google Scholar 

  • Liu C-Y, Yang Jing X, Yu B, Wu F-F (2015) Determination of support resistance of fully mechanized caving face in extra thick coal seam under the condition of multi-layer hard roof of overburden. J Min Saf Eng 32(01):7–13

    Google Scholar 

  • Liu F, Guo Z, Lv H, Cheng Z (2018) Test and analysis of blast wave in mortar test block. Int J Rock Mech Min Sci 108:80–85

    Article  Google Scholar 

  • Liu X, Cheng Z, Jin D (2020) Performance analysis of soft roadway surrounding rock in Yushujing coal mine. Geotech Geol Eng 38(1):497–505

    Article  Google Scholar 

  • Miao X-X, Qian M-G (1995) Mechanical model of surrounding rock and masonry beam in stope. Ground Press Strata Control z1: 3–12 + 197

  • Shi H (2005) Stability analysis and application of thick and hard roof in fully mechanized top coal caving stope. Shandong University of Science and Technology, Qingdao

    Google Scholar 

  • Shi L, Xu C, Cai Y, Geng X (2014) Dynamic impedances and free-field vibration analysis of pile groups in saturated ground. J Sound Vib 333(16):3709–3731

    Article  Google Scholar 

  • Wang J-C (2005) Discussion on fully mechanized caving mining technology and its deep development in China. Coal Sci Technol 01:14–17

    Google Scholar 

  • Wang J-H (2013) Key technology of large mining height fully mechanized caving mining in extra thick coal seam. J China Coal Soc 38(12):2089–2098

    Google Scholar 

  • Wang Z, Cheng Z (2016) Hard roof fracturing form and dynamic disaster control in short island mining face. Chin J Rock Mech Eng 35(S2):4018–4028

    Google Scholar 

  • Wang J, Ning J-G, Qian K, Sun Y, Ling Y-C (2014) The mechanical mechanism of the fracture formation of the combined three hinge arch of the compound roof roadway. Saf Coal Mines 45(12):64–67

    Google Scholar 

  • Wang J, Gao Z, Fu H, Ding G, Cai Y, Geng X, Shi C (2019) Effect of surcharge loading rate and mobilized load ratio on the performance of vacuum–surcharge preloading with PVDs. Geotext Geomembr 47(2):121–127

    Article  Google Scholar 

  • Wu J (1999) 15 years review of fully mechanized caving mining technology in China. China Coal Z1: 9–16 + 61

  • Yan H, He F-L, Wang S-G (2014) Roof control measures and safety evaluation of soft and thick coal seam in super large section roadway. Chin J Rock Mech Eng 33(05):1014–1023

    Google Scholar 

  • Yang S, Wang Z, Kong D, Cheng Z, Song G (2016) Overlying strata failure process and support resistance determination in large mining height face. J Min Saf Eng 33(2):199–207

    Google Scholar 

  • Yang D-M, Guo W-B, Zhao G-B, Tan Y, Yang W-Q (2019) Development height of water diversion fracture zone in fully mechanized caving mining under soft overburden of thick loose layer. J China Coal Soc 44(11):3308–3316

    Google Scholar 

  • Zhang Y, Cheng Z, Lv H (2019) Study on failure and subsidence law of frozen soil layer in coal mine influenced by physical conditions. Geomech Eng 18(1):97–109

    Google Scholar 

  • Zhao Y-X, Wang X-Z, Zhou J-L, Li Q-S, Zhang C (2019) The influence law of the basic top thickness span ratio of the comprehensive mining face on its initial fracture instability. J China Coal Soc 44(01):94–104

    Google Scholar 

  • Zheng S-S, Kong D-Z (2019) Fracture characteristics of hard top plate and migration law of overburden. Saf Coal Mines 50(05):257–262

    Google Scholar 

Download references

Acknowledgements

We acknowledge the financial support from the National Natural Science Foundation of China Youth Fund (Nos. 51904082, 51964007), and the Beijing Natural Science Foundation (2204080) and the Youth Science and Technology Talent Development Project of the Guizhou Education Department (Guizhou Education Co-operation KY character [2018] 114) and the Science and technology planning project of guizhou province (guizhou science and technology foundation [2020] 1y214).

Author information

Authors and Affiliations

  1. Mining College of Guizhou University, Guiyang, 550025, China

    Dezhong Kong, Qiang Li & Guiyi Wu

  2. Faculty of Resources and Safety Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China

    Dezhong Kong & Nan Wang

Authors
  1. Dezhong Kong
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Qiang Li
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Nan Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Guiyi Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Qiang Li.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Kong, D., Li, Q., Wang, N. et al. Analysis on the Breaking Law of Soft and Thick Roof of Fully Mechanized Top-Coal Caving Face. Geotech Geol Eng 38, 5941–5953 (2020). https://doi.org/10.1007/s10706-020-01404-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10706-020-01404-4

Keywords

Search

Navigation