Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway

The influence of mining on the upper section of working face leads to the fracture of the lateral key block of the roof. From the goaf to the coal body, a group of “left-middle-right” key blocks are formed. According to the three different spatial position structure relations formed by roadway and b...

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Main Authors: Xinfeng Wang, Mingyuan Lu, Yuhao Gao, Wenbo Luo, Wengang Liu
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:Advances in Civil Engineering
Online Access:http://dx.doi.org/10.1155/2020/6682303
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author Xinfeng Wang
Mingyuan Lu
Yuhao Gao
Wenbo Luo
Wengang Liu
author_facet Xinfeng Wang
Mingyuan Lu
Yuhao Gao
Wenbo Luo
Wengang Liu
author_sort Xinfeng Wang
collection DOAJ
description The influence of mining on the upper section of working face leads to the fracture of the lateral key block of the roof. From the goaf to the coal body, a group of “left-middle-right” key blocks are formed. According to the three different spatial position structure relations formed by roadway and broken key block in practical engineering, the mechanical causes of broken structure of key block in roof of roadway along goaf are analyzed. FLAC3D is used to simulate and analyze the deformation characteristics and stress state of key block structure model before and after roadway excavation, and the mechanical characteristics and instability mechanism of key block sliding and breaking under three spatial structure modes are obtained. With the help of the mathematical model of material mechanics, the structural mechanical behavior of key block model of roof before and after roadway excavation and the temporal and spatial evolution law of unloading and breaking are studied. The results show that the complex influence factors of mining disturbance and low strength of the weak rock mass will weaken the internal balance of “masonry beam” structure. When the roadway is located below the fracture line of the key block, the middle key block will rotate and lose stability with the side hinge joint of the goaf as the axis; when the roadway is located in the fracture line of the key block, it is easy for the middle key block to slide and lose stability; when the roadway is located outside the fracture line of the key block, the middle key block is in the state of complete collapse, the mechanical transmission mechanism of the surrounding rock in the vertical direction is weakened, and the surrounding rock is the most stable.
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spelling doaj-art-eb718fcb35ac4247a60d2ea97245b0d12025-08-20T03:21:18ZengWileyAdvances in Civil Engineering1687-80861687-80942020-01-01202010.1155/2020/66823036682303Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side RoadwayXinfeng Wang0Mingyuan Lu1Yuhao Gao2Wenbo Luo3Wengang Liu4College of Environment and Resources, Xiangtan University, Xiangtan, Hunan 411105, ChinaCollege of Environment and Resources, Xiangtan University, Xiangtan, Hunan 411105, ChinaCollege of Environment and Resources, Xiangtan University, Xiangtan, Hunan 411105, ChinaHunan Key Laboratory of Geomechanics and Engineering Safety, College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan, Hunan 411105, ChinaCollege of Environment and Resources, Xiangtan University, Xiangtan, Hunan 411105, ChinaThe influence of mining on the upper section of working face leads to the fracture of the lateral key block of the roof. From the goaf to the coal body, a group of “left-middle-right” key blocks are formed. According to the three different spatial position structure relations formed by roadway and broken key block in practical engineering, the mechanical causes of broken structure of key block in roof of roadway along goaf are analyzed. FLAC3D is used to simulate and analyze the deformation characteristics and stress state of key block structure model before and after roadway excavation, and the mechanical characteristics and instability mechanism of key block sliding and breaking under three spatial structure modes are obtained. With the help of the mathematical model of material mechanics, the structural mechanical behavior of key block model of roof before and after roadway excavation and the temporal and spatial evolution law of unloading and breaking are studied. The results show that the complex influence factors of mining disturbance and low strength of the weak rock mass will weaken the internal balance of “masonry beam” structure. When the roadway is located below the fracture line of the key block, the middle key block will rotate and lose stability with the side hinge joint of the goaf as the axis; when the roadway is located in the fracture line of the key block, it is easy for the middle key block to slide and lose stability; when the roadway is located outside the fracture line of the key block, the middle key block is in the state of complete collapse, the mechanical transmission mechanism of the surrounding rock in the vertical direction is weakened, and the surrounding rock is the most stable.http://dx.doi.org/10.1155/2020/6682303
spellingShingle Xinfeng Wang
Mingyuan Lu
Yuhao Gao
Wenbo Luo
Wengang Liu
Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway
Advances in Civil Engineering
title Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway
title_full Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway
title_fullStr Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway
title_full_unstemmed Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway
title_short Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway
title_sort structural mechanical characteristics and instability law of roof key block breaking in gob side roadway
url http://dx.doi.org/10.1155/2020/6682303
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