Research and application of fracture mechanics model of stope roof under the coupling of direct roof and basic roof

Authors

LI Jinhua, College of Architecture and Civil Engineering, Xi’an University of Science and Technology, Xi’an 710054, ChinaFollow
ZHENG Chengxian, College of Architecture and Civil Engineering, Xi’an University of Science and Technology, Xi’an 710054, ChinaFollow
GU Shuancheng, College of Architecture and Civil Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
WU Baolin, College of Architecture and Civil Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
WANG Xiong, College of Architecture and Civil Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
SONG Yongjun, College of Architecture and Civil Engineering, Xi’an University of Science and Technology, Xi’an 710054, China

Abstract

Periodic weighting is a typical characteristic of mine pressure. Accurate prediction of stope periodic weighting step is an important way to effectively reduce the occurrence of stope accidents. Aiming at the influence of the coupling between the basic roof defects and the direct roof on the periodic weighting step, the stope roof was regarded as a finite plate model with cracks. According to the coordinate deformation mechanism of the overburden rock, the fracture mechanics model of the stope roof was established based on the fracture mechanics theory. On this basis, the periodic weighting step function under the coupling between the direct roof and basic roof was derived. In addition, the influence of the parameters such as the fracture toughness of the basic roof rock, crack depth, direct roof thickness and elastic modulus on the periodic weighting step was analyzed based on 2 working faces of a mine area in northern Shaanxi. The research shows that: (1) The fracture toughness of the basic roof is in approximately linear relation with the periodic weighting step. (2) The crack depth ratio (crack depth/roof thickness) has a great influence on the periodic weighting step. In particular, the basic roof is unstable and destroyed when the crack depth ratio reaches 0.8. (3) The direct roof with the thickness less than 3 m has little effect on the periodic weighting step, but that with the thickness greater than 3 m has a significant effect on the periodic weighting step. Generally, the research results have important theoretical significance and engineering value for the prediction of periodic weighting step of stope roof and the selection of support.

Keywords

fracture mechanics, coordinate deformation, coupling of direct roof and basic roof, periodic weighting step

DOI

10.12363/issn.1001-1986.23.02.0084

Recommended Citation

LI Jinhua, ZHENG Chengxian, GU Shuancheng, et al. (2023) "Research and application of fracture mechanics model of stope roof under the coupling of direct roof and basic roof," Coal Geology & Exploration: Vol. 51: Iss. 7, Article 14.
DOI: 10.12363/issn.1001-1986.23.02.0084
Available at: https://cge.researchcommons.org/journal/vol51/iss7/14

Reference

[1] 钱鸣高，石平五，许家林. 矿山压力与岩层控制[M]. 徐州：中国矿业大学出版社，2010.

[2] 宋振骐. 实用矿山压力控制[M]. 徐州：中国矿业大学出版社，1988.

[3] 钱鸣高,缪协兴,许家林. 岩层控制中的关键层理论研究[J]. 煤炭学报,1996,21(3):225−230.

QIAN Minggao,MIAO Xiexing,XU Jialin. Theoretical study of key stratum in ground control[J]. Journal of China Coal Society,1996,21(3):225−230.

[4] 宋振骐,蒋宇静,刘建康. “实用矿山压力控制”的理论和模型[J]. 煤炭科技,2017(2):1−10.

SONG Zhenqi,JIANG Yujing,LIU Jiankang. Theory and model of “practical method of mine pressure control”[J]. Coal Science & Technology Magazine,2017(2):1−10.

[5] 郑凯歌,王林涛,李彬刚,等. 坚硬顶板强矿压动力灾害演化机理与超前区域防治技术[J]. 煤田地质与勘探,2022,50(8):62−71.

ZHENG Kaige,WANG Lintao,LI Bingang,et al. Dynamic disaster evolution mechanism of high mine pressure at hard roof and advance area prevention and control technology[J]. Coal Geology & Exploration,2022,50(8):62−71.

[6] 李金华,段东,岳鹏举,等. 坚硬顶板强制放顶断裂力学模型研究[J]. 煤田地质与勘探,2018,46(6):128−132.

LI Jinhua,DUAN Dong,YUE Pengju,et al. Study on the fracture mechanics model of forced caving of hard roof[J]. Coal Geology & Exploration,2018,46(6):128−132.

[7] 李金华,陈文晓,苏培莉,等. 深孔预裂强制放顶断裂力学模型研究[J]. 煤田地质与勘探,2020,48(6):217−223.

LI Jinhua,CHEN Wenxiao,SU Peili,et al. Research on the fracture mechanics model of deep hole pre–splitting for forced caving[J]. Coal Geology & Exploration,2020,48(6):217−223.

[8] 题正义,张峰,秦洪岩,等. 基于板壳和断裂力学理论的上覆采空区积水危险性判定技术[J]. 煤田地质与勘探,2019,47(1):138−143.

TI Zhengyi,ZHANG Feng,QIN Hongyan,et al. Risk judgment technology of water accumulation in overlying goaf based on plate shell and fracture mechanics theory[J]. Coal Geology & Exploration,2019,47(1):138−143.

[9] HU Jianhua,LEI Tao,ZHOU Keping,et al. Mechanism on simulation and experiment of pre−crack seam formation in stope roof[J]. Journal of Central South University,2014,21(4):1526−1533.

[10] 陈新年,王景春,熊咸玉,等. 煤巷复合顶板结构对其稳定性影响试验[J]. 煤田地质与勘探,2019,47(2):157−161.

CHEN Xinnian,WANG Jingchun,XIONG Xianyu,et al. Influence of composite roof structure on the stability of coal roadway[J]. Coal Geology & Exploration,2019,47(2):157−161.

[11] 张杰. 采高对浅埋煤层老顶岩层破断距的影响[J]. 辽宁工程技术大学学报(自然科学版),2009,28(2):161−164.

ZHANG Jie. Influence of mining height of main roof on broken length[J]. Journal of Liaoning Technical University (Natural Science),2009,28(2):161−164.

[12] 谷拴成,李金华,黄荣宾. 采场直接顶对周期来压步距的影响[J]. 矿业安全与环保,2015,42(5):34−37.

GU Shuancheng,LI Jinhua,HUANG Rongbin. Influence of stope immediate roof on periodic weighting distance[J]. Mining Safety & Environmental Protection,2015,42(5):34−37.

[13] 谷拴成,黄荣宾,苏培莉. 直接顶岩层特性对综采工作面周期来压步距的影响[J]. 煤炭技术,2017,36(7):4−6.

GU Shuancheng,HUANG Rongbin,SU Peili. Influence of characteristics of immediate roof strata on periodic weighting length in fully mechanized coal face[J]. Coal Technology,2017,36(7):4−6.

[14] 弓培林,靳钟铭. 大采高综采采场顶板控制力学模型研究[J]. 岩石力学与工程学报,2008,27(1):193−198.

GONG Peilin,JIN Zhongming. Mechanical model study on roof control for fully−mechanized coal face with large mining height[J]. Chinese Journal of Rock Mechanics and Engineering,2008,27(1):193−198.

[15] 刘长友,万志军,曹胜根. 直接顶岩层力学特性对综放采场煤岩破坏的影响规律[J]. 矿山压力与顶板管理,2002,19(1):64−66.

LIU Changyou,WAN Zhijun,CAO Shenggen. Effect of mechanical properties of direct roof strata on the destruction of coal rock in fully mechanized stope[J]. Ground Pressure and Strata Control,2002,19(1):64−66.

[16] FENG Qiang,FU Shenggang,WANG Chengxiang,et al. Analytical solution for fracture of stope roof based on Pasternak Foundation model[J]. Soil Mechanics and Foundation Engineering,2019,56(2):142−150.

[17] GONG Tao,XIA Binwei,LU Yiyu,et al. Study on the maximum pressure−causing stratum in longwall mining stope and its mechanics analysis[J]. Arabian Journal of Geosciences,2020,13:566.

[18] LUO Zhouquan,XIE Chengyu,JIA Nan,et al. Safe roof thickness and span of stope under complex filling body[J]. Journal of Central South University,2013,20(12):3641−3647.

[19] 杨登峰,陈忠辉,孙建伟,等. 大采高长壁工作面顶板垮落的裂纹板力学模型[J]. 东南大学学报(自然科学版),2016,46(增刊1):210−216.

YANG Dengfeng,CHEN Zhonghui,SUN Jianwei,et al. Crack plate mechanical model for large mining height and longwall face of roof caving[J]. Journal of Southeast University (Natural Science Edition),2016,46(Sup.1):210−216.

[20] 孙闯,宋业杰. 基于断裂力学的长壁工作面导水裂缝带高度预计[J]. 煤矿开采,2016,21(3):81−84.

SUN Chuang,SONG Yejie. Predict of diversion fissure zone height of long wall face based on fracture mechanics[J]. Coal Mining Technology,2016,21(3):81−84.

[21] 唐铁吾,刘大安,崔振东,等. 煤矿顶板致裂水压力的断裂力学评估[J]. 煤炭学报,2020,45(增刊2):727−735.

TANG Tiewu,LIU Da’an,CUI Zhendong,et al. Initiation pressure evaluation of coal mine roof hydraulic fracturing based on fracture mechanics[J]. Journal of China Coal Society,2020,45(Sup.2):727−735.

[22] 王进学,王家臣,陈忠辉. “两硬”浅埋深厚煤层顶煤顶板运移规律研究[J]. 采矿与安全工程学报,2006,23(2):228−232.

WANG Jinxue,WANG Jiachen,CHEN Zhonghui. Movement rule of shallowly–buried thick coal seams with hard top coal and roof[J]. Journal of Mining & Safety Engineering,2006,23(2):228−232.

[23] 中国航空研究院. 应力强度因子手册[M]. 北京：科学出版社，1981.