摘要
合理空顶距的确定对巷道安全高效掘进意义重大。采用理论推导计算与数值模拟相结合的方法,对不同空顶距离的掘进巷道围岩应力分布及塑性区演化特征进行分析,并提出安全合理空顶距离及支护优化设计。结果表明:掘进工作面超前煤体内部塑性区宽度与超越函数特征值呈负相关自然对数关系,当特征值为0时,塑性区最大宽度为2.02 m;推导所得公式中煤层埋深、巷道断面尺寸及煤岩物理力学参数是影响塑性区数值大小的主要因素;受载矩形薄板最大跨度取决于薄板中心处拉应力大小,拉应力与直接顶抗拉强度比值大于1,顶板发生力学破断;掘进工作面超前煤体应力场遵循非均匀连续性且在模型固支边逐渐增大的特征规律,模拟结果印证了4.71m计算结果为极限空顶距离,此时顶板未发生破断;在保证井下作业安全的前提条件下,确定4.0m为空顶距离,提高综掘效率,加快成巷速度,缓解采掘接替紧张。
The determination of reasonable unsupported roof distance is of great significance to safe and efficient roadway excavation. The stress distribution and plastic zone evolution characteristics of surrounding rock of tunneling roadway with different unsupported roof distance were analyzed through theoretical deduction calculation and numerical simulation, and safe and reasonable roof distance and optimized design of support was proposed. The results have shown that the width of the plastic zone in the coal body ahead of the driving face is negatively correlated with the characteristic value of the transcendental function. When the characteristic value is 0, the maximum width of the plastic zone is 2.02 m;the depth of coal seam, the size of roadway section and the physical and mechanical parameters of coal and rock are the main factors affecting the numerical value of the plastic zone;the maximum span of the loaded rectangular thin plate depends on the tensile stress acting at the center of the thin plate, and the direct roof will be destroyed while the ratio of tensile stress to the tensile strength of the direct roof is greater than 1;the stress field of the coal body in advance of the driving face follows the characteristic law of inhomogeneous continuity and increasing at the fixed support edge of the model;the simulation result confirms that the 4.71 m calculation result is the limit unsupported roof distance,and the roof did not break at this time;to ensure the safety of downhole operations, premise condition is determined as 4.0 m unsupported roof distance which improves the efficiency of comprehensive mechanized excavation, speeds up roadway formation, and alleviates the tight problem between mining and tunneling.
作者
丁自伟
李小菲
张杰
赵志强
薛斌
邸广强
沈少康
DING Ziwei;LIXiaofei;ZHANG Jie;ZHAO Zhiqiang;XUE Bin;DI Guangqiang;SHEN Shaokang(College of Energy Engineering,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China;Shaanxi Hancheng Coal Mining Co Ltd,Hancheng,Shaanxi 715400,China;School of Energy and Mining Engineering,China University of Mining and Technology,Beijing,Beijing 100083,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2021年第3期507-517,共11页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(52074209,51874232,51504183)
陕西省自然科学基础研究计划联合基金项目(2021JLM-06)。
关键词
煤层巷道
板壳理论
物理力学模型
空顶距离
超越函数
模拟仿真
coal seam roadway
mechanics of plate and shell
physical and mechanical model
unsupported roof distance
transcendental function
simulation
