摘要
以超长工作面基本顶初次断裂所成铰拱结构为力学模型,在铰接端接触面按照应力指数分布规律,得出新的水平推力公式。通过严格几何变形推导出铰接端变形量与下沉量,结合数值模拟与现场实例进行验算,应用新的推力公式对结构稳定性进行判断。与传统近似建模方法相比,经研究发现:针对浅埋超长工作面,在回转角小于3°时,块度i>0.40的断块所受推力随工作面长度、回转角变大而以微小变化率增加,块度i<0.45时断块不发生滑落失稳;块度i≤0.30的断块所受水平推力T增幅明显,若回转角?超过6°,断块易因T过大而发生变形失稳;新公式代入实例得出的回转稳定区范围比传统范围至少大12%。给出了浅埋裂隙梁结构允许埋深公式,对浅埋超长工作面裂隙结构失稳预测有参考价值。
The stress distribution of a hinged arch, which is formed by the initially-fracturing main roof, is analyzed, and a new formulation for horizontal thrust is developed by adopting an exponential law. Based on strict geometric transformation, the amount of deformation and subsidence are obtained. The results are validated by comparing the calculated results of the proposed formulation to the numerical results and field observations. The new formulation for thrust is applied to evaluate the structural stability. It is found that for shallow super-long mining face, when the angle of rotation is less than 3°, the thrust of the block with fragmentation i 〉0.4 increases slightly with the length of mining face and the angle of rotation, and the block fails to destablize due to sliding when i〈0.45; if i≤0.3 the thrust increases significantly; the block is prone to fail due to overhigh thrust when the angle of rotation is more than 6°; the stable range for rotation by the proposed formulation is 12%, at least larger than the traditional range.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第1期203-209,共7页
Rock and Soil Mechanics
基金
国家科技支撑计划资助项目(No.2007BAK29B02)~~
关键词
浅埋煤层
超长工作面
裂隙梁失稳预测
数值模拟
shallow seam
super-long mining surface
instability forecast for hinged arch structure of fractured beam
numerical simulation
