含水量对沉积岩力学性质及其冲击倾向性的影响

 通过试验和统计分析系统研究不同含水条件下煤系沉积岩石力学性质及其冲击倾向性，建立岩石力学性质及其冲击倾向性与含水量之间的相关关系和模型，揭示含水量对岩石力学性质及其冲击倾向性的控制机制。研究表明：岩石单轴抗压强度和弹性模量值随含水量的增加而降低；不同岩性岩石单轴抗压强度和弹性模量值受含水量的影响程度不同，降低的速率受岩性所控制。在干燥或较少含水量情况下，应力–应变曲线在峰值强度后岩石表现为脆性和剪切破坏，具有明显的应变软化特性，且随着含水量的增加，峰值强度后岩石主要为塑性破坏，应变软化特性不明显。随着含水量的增加，岩石脆性指标修正值(BIM)逐渐增加，弹性变形指数逐渐减小，岩石在受力过程中储存的弹性应变能随含水量的增加而急剧减少，而消耗的塑性永久变形能相对增加，即岩石的冲击倾向性随含水量的增加而显著降低。

INFLUENCE OF MOISTURE CONTENTS ON MECHANICAL PROPERTIES OF SEDIMENTARY ROCK AND ITS BURSTING POTENTIAL

The mechanical properties of coal series sedimentary rock and its bursting potential in different moisture contents are studied，and the models and correlations between moisture content and bursting potential are established. The controlling mechanism of moisture content of mechanical properties of sedimentary rock and its bursting potential is also revealed. It is shown that the uniaxial compressive strength and the values of elastic modulus decrease with the increase of moisture content，whose influence degree differs from lithology，and the decreasing rates are controlled by lithology. The rock after peak strength of stress-strain curve represents brittleness and shear failure has obvious strain softening behavior in the condition of dried or with small moisture content. With increase of moisture content，the brittleness index modified(BIM) of rock increases gradually，while elastic deformation exponential decreases and the stored elastic strain energy decreases sharply in the process of stress；however，the consumed permanent plastic deformation energy increases relatively，which means that the bursting potential of rock decreases significantly with the increase of moisture content.