Analysis of Roof Deformation Mechanism and Control Measures with Roof Cutting and Pressure Releasing in Gob‐Side Entry Retaining

Huang

Energy Science & Engineering

et al. 2021

Recently, concerns regarding coal resource waste and safety mining have grown worldwide. The no-pillar mining method without advance tunneling, known as the N00 longwall mining method, represents a rational alternative in this regard.Since the 20th century, coal mining technology has undergone long-term development in China. The mining methods used in China's coal industry can be classified into three types: longwall mining, gob-side entry retaining, and N00 longwall mining.The longwall mining method, which originated in Britain during the early 18th century, was first used in China in the 1930s and has been developed for approximately 90 years. It has become one of the landmark achievements in the field of coal mining in China. 1,2 However, a large coal pillar measuring 20-50 m and double advance tunneling roadways should be set up before stopping a working face when using this mining method. This results in low coal recovery rates and mining productivity. Hence, the contradiction between this mining method and China's energy characteristics has become more prominent.

mentioning

confidence: 99%

Validation study of no‐pillar mining method without advance tunneling: A case study of a mine in China

Huang

Energy Science & Engineering

et al. 2021

“…To this end, scholars have proposed various types of active, passive, and combined supports through a variety of methods [3][4][5]. Overall, the roadway surrounding-rock control can be divided into fve basic support forms, namely, the basic support within the roadway [6,7] (wood bracket, metal bracket, and stone bracket), strengthening support in roadway [8,9] (permanent strengthening support and temporary strengthening support such as single hydraulic prop), roadway side support [10,11] (wood crib, dense pillar, gangue wall, concrete wall, and flling wall), grouting modifcation [12][13][14] (ordinary portland cement, Marysan, and new polymer organic and inorganic modifed materials), nonsingle support form [15][16][17] (above two and multiple combined support technologies). Te surroundingrock supporting theory of coal mine roadway mainly includes suspension theory, composite beam theory, composite arch theory, maximum horizontal stress theory, and surrounding rock strength strengthening theory [18].…”

Section: Introductionmentioning

confidence: 99%

Control Effect Analysis and Engineering Application of Anchor Cable Beam-Truss Structure on Large-Deformation Roadway in Deep Coal Mine

Wang,

Yin,

Zhao

et al. 2024

Shock and Vibration

In response to the shortcomings of the small support scope of single anchor cable and failure to fully utilize the joint anchoring for surrounding rock, this study summarizes the classification of basic support forms for coal mine roadway surrounding rock and clarifies the main composition and mechanism of anchor cable beam-truss structure. A mechanical model of roadway roof beam under the conditions of no support, single anchor cable support, and anchor cable beam-truss structure support at both ends of the roadway is constructed, and the force and maximum bending moment of roadway roof beam under different support types are compared and analyzed. The study clarifies the bending moment reduction rate of anchor cable beam-truss structure relative to unsupported and single anchor cable support and combines numerical simulation to analyze the response laws of anchor cable beam-truss to prestress distribution and stress shell in roadway surrounding rock. Based on the on-site engineering application of a typical large-deformation mining roadway in a deep coal mine, the important role of anchor cable beam-truss structure in ensuring the safety and stability of surrounding rock in deep high-stress and intense-mining large-deformation roadway is revealed, providing technical references for surrounding rock control of similar conditions in deep roadways.

“…In addition, along the goaf edge, the energyaccumulated blasting technology 14 is used to cut the roof, which cuts off the stress transmission in the lateral direction and optimizes the stress distribution of the surrounding rock in the goaf. 15,16 Under the traditional longwall mining mode, the roof cannot fully collapse because of the support of the coal pillars in the goaf area, and the coal pillar-influenced areas are formed on both sides of the coal pillars. 17 The porosity and permeability in this area are relatively large.…”

Section: Introductionmentioning

confidence: 99%

“…This mining technology only needs to excavate a roadway or no roadway in one mining face, thereby reducing the amount of roadway excavation, achieving pillarless mining, and increasing the coal recovery rate. In addition, along the goaf edge, the energy-accumulated blasting technology is used to cut the roof, which cuts off the stress transmission in the lateral direction and optimizes the stress distribution of the surrounding rock in the goaf. , …”

Section: Introductionmentioning

confidence: 99%

Characteristics of Airflow Migration in Goafs under the Roof-Cutting and Pressure-Releasing Mode and the Traditional Longwall Mining Mode

Chen

Jia

et al. 2021

ACS Omega

The airflow exchange between a mining face and a coal mine goaf can cause gas transfinite and spontaneous coal combustion disasters, threatening coal mining. Studying the characteristics of airflow movement in a goaf forms the basis to prevent airflow exchange for coal mining safety. Different from the traditional longwall mining mode, the roof-cutting and pressure-releasing mining mode shows new roof collapse characteristics and a ventilation system, which lead to obvious changes in the characteristics of airflow movements in coal mine goafs. To study the differences in airflow movement characteristics and the airflow disturbance influence area in a coal mine goaf between these two mining modes, the airflow movements in different goafs are compared using a numerical simulation method based on the measured parameters of the 1201 mining face in the Halagou Coal Mine, China. The results show that the airflow disturbance area in the goaf under the traditional longwall mining mode is a “η” type. Along the inclination direction of the mining face, two main exchange areas for the airflow are located in the 0–5 and 15–45 m sections, respectively. The airflow disturbance area in the goaf under the roof-cutting and pressure-releasing mining mode is a “hump” type, and there are six main exchange areas in the goaf under the roof-cutting and pressure-releasing mining mode. Along the inclination direction of the mining face, three exchange areas are located in the 0–25, 255–305, and 305–320 m sections, respectively. Along the strike direction, three exchange areas are located in the 5–25, 25–35, and 35–65 m sections, respectively. Based on the research results, sealing measures are taken to slow and eliminate airflow exchange in the goaf under the roof-cutting and pressure-releasing mining mode, and this provides theoretical guidance for safe coal mining.