For studying the strata behavior due to multi-slicing top coal caving longwall mining along-the-strike direction in steeply dipping extra thick coal seams,the shield support pressures of the upper and lower slices of ...For studying the strata behavior due to multi-slicing top coal caving longwall mining along-the-strike direction in steeply dipping extra thick coal seams,the shield support pressures of the upper and lower slices of panel 37220 in Dongxia Coal Mine were monitored using the KJ513 dynamic monitoring system.The set up rooms adopted the "horizontal line-arc segment-inclined line" form and used different types of shield supports.The results show that the strata pressure of upper slice panel 37220-1 changed slightly along the strike direction,while along the dip direction it exhibited strong to weak pressure from bottom to top.The first weighting interval of lower slice panel 37220-2 was about 60.8 m,and the average periodic weighting interval were about 22.6 m.The strata behavior of panel 37220-2 exhibited a spatiotemporal characteristic in that periodic weighting occurred first in the middle-upper part,followed by the middle and upper parts,arc segment,and finally the lower part.During the periodic weighting,the weighting interval and intensity also exhibited strong space characteristics.The average dynamic load coefficient was 1.48 and the maximum lateral load of the side shield was 20-25 MPa.展开更多
Based on the character of upward slicing backfilling mining and the condition of Gonggeyingzi coal mine in Inner Mongolia,this paper describes the studies of the strata behavior and the stress distribution in the proc...Based on the character of upward slicing backfilling mining and the condition of Gonggeyingzi coal mine in Inner Mongolia,this paper describes the studies of the strata behavior and the stress distribution in the process of backfilling mining in extra-thick coal seams.This was achieved by setting up and analyzing the elastic foundation beam model using the ABAQUS software.The results show that:(1) With the gradual mining of different slices,the roof appears to bend continuously but does not break.The vertical stress in the roof decreases and the decreasing amplitude reduces,while the tensile stress in the roof grows with the mining slices and the maximum tensile stress will not exceed the allowable tensile stress.(2) The front vertical stress at the working face exceeds the rear vertical stress and both show a trend of decrease with decreasing amplitude of decrease.(3) The slices mined early have more influence on the surrounding rock than the later ones.Similarly,the strata behavior experiences the same trend.The field measured data show that the roof does not break during the mining process,which is consistent with the conclusion.展开更多
Based on the dividing of derormation zones of tailentry in working face and the classification of driving metbods, toking the way of field measurement, this paper fiuds out some changing regularities of main deformati...Based on the dividing of derormation zones of tailentry in working face and the classification of driving metbods, toking the way of field measurement, this paper fiuds out some changing regularities of main deformation parameters of a tailentry in 2# coal seam in Suncun Colliery with the incrcasing of mining depth, and puts forward some layout methods to protect the tailentry in deep mining.展开更多
Accidents such as support failure and excessive deformation of roadways due to drastic changes in strata behaviors are frequently reported when mining the extra-thick coal seams Nos.3e5 in Datong coal mine with top-co...Accidents such as support failure and excessive deformation of roadways due to drastic changes in strata behaviors are frequently reported when mining the extra-thick coal seams Nos.3e5 in Datong coal mine with top-coal caving method,which significantly hampers the mine's normal production.To understand the mechanism of strata failure,this paper presented a structure evolution model with respect to strata behaviors.Then the behaviors of strata overlying the extra-thick coal seams were studied with the combined method of theoretical analysis,physical simulation,and field measurement.The results show that the key strata,which are usually thick-hard strata,play an important role in overlying movement and may influence the mining-induced strata behaviors in the working face using top-coal caving method.The structural model of far-field key strata presents a 'masonry beam' type structure when'horizontal O-X' breakage type happens.The rotational motion of the block imposed radial compressive stress on the surrounding rock mass of the roadway.This can induce excessive deformation of roadway near the goaf.Besides,this paper proposed a pre-control technology for the hard roof based on fracture holes and underground roof pre-splitting.It could effectively reduce stress concentration and release the accumulated energy of the strata,when mining underground coal resources with top-coal caving method.展开更多
In order to investigate the behaviors and stability of rock strata surrounding an entry with bolt supporting in large dip coal seams (LDCSs) dipping from 25° to 45°, a self-developed rotatable experimental f...In order to investigate the behaviors and stability of rock strata surrounding an entry with bolt supporting in large dip coal seams (LDCSs) dipping from 25° to 45°, a self-developed rotatable experimental frame for similar material simulation test was used to build the model with the dip of 30°, based on analyses of geological and technological conditions in Huainan mine area, Anhui, China. The strata behaviors, such as extracting- and mining-induced stresses development, deformation and failure modes, were synthetically integrated during working face advancing. Results show that the development characteristics of mining-induced stress and deformation are asymmetrical in the roadway. The strata behaviors are totally different in different sections of the roadway. Because of asymmetrically geometrical structure influenced by increasing dip, strata dislocating, rock falling and breaking occur in roof. Then, squeezing, collapsing and caving of coal happen in upper- and lower-rib due to shearing action caused by asymmetrical roof bending and dislocating. Owing to the absence of supporting, floor heaving is very violent and usually the zone of floor heaving develops from the lower-rib to upper-rib. Engineering practices show that, due to the asymmetrical characteristics of rock pressure and roadway configuration, it is more difficult to implement bolt supporting system to control rock stability of roadways in LDCSs. The upper-rib and roof of entries are the key sections. Consequently, it is reliable to use asymmetrical bolt-mesh-cable supporting system to control rock stability of roadways based on the asymmetrical characteristics of roadway configuration and strata behaviors.展开更多
高强度开采和工作面长度增加使得矿压显现规律和时空分布特征出现变化,实现顶板来压的智能预测对于保障矿井安全生产具有重要意义。以陕西榆横矿区袁大滩煤矿中厚煤层加长工作面高强度开采的矿压演化趋势和分级预测为背景,分析了加长工...高强度开采和工作面长度增加使得矿压显现规律和时空分布特征出现变化,实现顶板来压的智能预测对于保障矿井安全生产具有重要意义。以陕西榆横矿区袁大滩煤矿中厚煤层加长工作面高强度开采的矿压演化趋势和分级预测为背景,分析了加长工作面支架阻力的分布特征和矿压显现规律,将工作面矿压数据动态映射至具有拓扑关系的空间网格单元,利用无监督聚类算法提取了工作面支架时空关联特征,形成了时空联动的支架阻力分析方法,构建了基于patch机制的Transformer(Patch Time Series Transformer,PatchTST)矿压预测模型,基于现场实测数据横向对比测试了多种预测模型,验证了PatchTST的准确性和对矿压长序列预测的适用性,最后进行了工程应用性能测试和预测误差分析。结果表明:袁大滩煤矿11207加长工作面倾向方向压力分布呈现“双波峰−谷间震荡”的“M”型特征,随着推进度和时间推移,“M”型压力场总体呈现出“形成−稳定−递归”的周期性演化规律;矿压数据经过空间网格单元的动态映射和聚类分析后,可以精确辨识工作面来压积聚区域并实现来压强度分级的自动求解;PatchTST模型在回视窗口240,预测步长为3的情况下预测精度最佳,评估指标M_(SE)值和M_(AE)值分别为0.095、0.240;横向对比多个基于注意力机制的模型,PatchTST模型均能做到最低的预测误差;工程应用性能测试表明,所用方法准确辨识了现场观测较为强烈的来压,误差分析同样表明模型的预测精度较高,准确率可达92.8%。研究可为加长工作面矿压显现规律及工作面来压的智能预测预警提供借鉴与参考。展开更多
基金funds supported by the Key Program of National Natural Science Foundation of China(No.51634007)
文摘For studying the strata behavior due to multi-slicing top coal caving longwall mining along-the-strike direction in steeply dipping extra thick coal seams,the shield support pressures of the upper and lower slices of panel 37220 in Dongxia Coal Mine were monitored using the KJ513 dynamic monitoring system.The set up rooms adopted the "horizontal line-arc segment-inclined line" form and used different types of shield supports.The results show that the strata pressure of upper slice panel 37220-1 changed slightly along the strike direction,while along the dip direction it exhibited strong to weak pressure from bottom to top.The first weighting interval of lower slice panel 37220-2 was about 60.8 m,and the average periodic weighting interval were about 22.6 m.The strata behavior of panel 37220-2 exhibited a spatiotemporal characteristic in that periodic weighting occurred first in the middle-upper part,followed by the middle and upper parts,arc segment,and finally the lower part.During the periodic weighting,the weighting interval and intensity also exhibited strong space characteristics.The average dynamic load coefficient was 1.48 and the maximum lateral load of the side shield was 20-25 MPa.
基金sponsored by the National Key Basic Research Program of China (No.2013CB227905)Qinglan Projects of Jiangsu Province
文摘Based on the character of upward slicing backfilling mining and the condition of Gonggeyingzi coal mine in Inner Mongolia,this paper describes the studies of the strata behavior and the stress distribution in the process of backfilling mining in extra-thick coal seams.This was achieved by setting up and analyzing the elastic foundation beam model using the ABAQUS software.The results show that:(1) With the gradual mining of different slices,the roof appears to bend continuously but does not break.The vertical stress in the roof decreases and the decreasing amplitude reduces,while the tensile stress in the roof grows with the mining slices and the maximum tensile stress will not exceed the allowable tensile stress.(2) The front vertical stress at the working face exceeds the rear vertical stress and both show a trend of decrease with decreasing amplitude of decrease.(3) The slices mined early have more influence on the surrounding rock than the later ones.Similarly,the strata behavior experiences the same trend.The field measured data show that the roof does not break during the mining process,which is consistent with the conclusion.
文摘Based on the dividing of derormation zones of tailentry in working face and the classification of driving metbods, toking the way of field measurement, this paper fiuds out some changing regularities of main deformation parameters of a tailentry in 2# coal seam in Suncun Colliery with the incrcasing of mining depth, and puts forward some layout methods to protect the tailentry in deep mining.
基金supported by the Special Funding Projects of“Sanjin Scholars”Supporting Plan(Grant No.2050205)
文摘Accidents such as support failure and excessive deformation of roadways due to drastic changes in strata behaviors are frequently reported when mining the extra-thick coal seams Nos.3e5 in Datong coal mine with top-coal caving method,which significantly hampers the mine's normal production.To understand the mechanism of strata failure,this paper presented a structure evolution model with respect to strata behaviors.Then the behaviors of strata overlying the extra-thick coal seams were studied with the combined method of theoretical analysis,physical simulation,and field measurement.The results show that the key strata,which are usually thick-hard strata,play an important role in overlying movement and may influence the mining-induced strata behaviors in the working face using top-coal caving method.The structural model of far-field key strata presents a 'masonry beam' type structure when'horizontal O-X' breakage type happens.The rotational motion of the block imposed radial compressive stress on the surrounding rock mass of the roadway.This can induce excessive deformation of roadway near the goaf.Besides,this paper proposed a pre-control technology for the hard roof based on fracture holes and underground roof pre-splitting.It could effectively reduce stress concentration and release the accumulated energy of the strata,when mining underground coal resources with top-coal caving method.
基金Supported by the National Basic Research Program of China (2010CB226806)the Visiting Scholar Foundation of Key Laboratory for Exploitation of Southwestern Resources and Environmental Disaster Control Engineeringthe Outstanding Innovation Group Program of Anhui University of Science and Technology
文摘In order to investigate the behaviors and stability of rock strata surrounding an entry with bolt supporting in large dip coal seams (LDCSs) dipping from 25° to 45°, a self-developed rotatable experimental frame for similar material simulation test was used to build the model with the dip of 30°, based on analyses of geological and technological conditions in Huainan mine area, Anhui, China. The strata behaviors, such as extracting- and mining-induced stresses development, deformation and failure modes, were synthetically integrated during working face advancing. Results show that the development characteristics of mining-induced stress and deformation are asymmetrical in the roadway. The strata behaviors are totally different in different sections of the roadway. Because of asymmetrically geometrical structure influenced by increasing dip, strata dislocating, rock falling and breaking occur in roof. Then, squeezing, collapsing and caving of coal happen in upper- and lower-rib due to shearing action caused by asymmetrical roof bending and dislocating. Owing to the absence of supporting, floor heaving is very violent and usually the zone of floor heaving develops from the lower-rib to upper-rib. Engineering practices show that, due to the asymmetrical characteristics of rock pressure and roadway configuration, it is more difficult to implement bolt supporting system to control rock stability of roadways in LDCSs. The upper-rib and roof of entries are the key sections. Consequently, it is reliable to use asymmetrical bolt-mesh-cable supporting system to control rock stability of roadways based on the asymmetrical characteristics of roadway configuration and strata behaviors.
文摘高强度开采和工作面长度增加使得矿压显现规律和时空分布特征出现变化,实现顶板来压的智能预测对于保障矿井安全生产具有重要意义。以陕西榆横矿区袁大滩煤矿中厚煤层加长工作面高强度开采的矿压演化趋势和分级预测为背景,分析了加长工作面支架阻力的分布特征和矿压显现规律,将工作面矿压数据动态映射至具有拓扑关系的空间网格单元,利用无监督聚类算法提取了工作面支架时空关联特征,形成了时空联动的支架阻力分析方法,构建了基于patch机制的Transformer(Patch Time Series Transformer,PatchTST)矿压预测模型,基于现场实测数据横向对比测试了多种预测模型,验证了PatchTST的准确性和对矿压长序列预测的适用性,最后进行了工程应用性能测试和预测误差分析。结果表明:袁大滩煤矿11207加长工作面倾向方向压力分布呈现“双波峰−谷间震荡”的“M”型特征,随着推进度和时间推移,“M”型压力场总体呈现出“形成−稳定−递归”的周期性演化规律;矿压数据经过空间网格单元的动态映射和聚类分析后,可以精确辨识工作面来压积聚区域并实现来压强度分级的自动求解;PatchTST模型在回视窗口240,预测步长为3的情况下预测精度最佳,评估指标M_(SE)值和M_(AE)值分别为0.095、0.240;横向对比多个基于注意力机制的模型,PatchTST模型均能做到最低的预测误差;工程应用性能测试表明,所用方法准确辨识了现场观测较为强烈的来压,误差分析同样表明模型的预测精度较高,准确率可达92.8%。研究可为加长工作面矿压显现规律及工作面来压的智能预测预警提供借鉴与参考。
