为揭示煤高度影响的煤和组合煤岩力学性质演化规律，通过开展煤和组合煤岩试样单轴压缩试验，从强度、弹性模量、破坏特征及能量累积等角度对2者异同性进行分析，厘清了煤高度影响的2类试样力学性质变化规律和能量累积耗散演化规律，提出了一种针对组合煤岩试样的冲击倾向性判定方法。结果表明：随煤高度增加，煤试样和组合煤岩试样的弹性模量趋于一个定值;煤试样的强度与试样高度无明显关系，组合试样的强度随煤高度增加而降低;煤试样的应力峰值变形量在0.5~1.5 mm，随试样高度降低破坏特征从脆性破坏向半脆性破坏转变;组合煤岩试样的应力峰值变形量在1~2 mm，破坏特征均为脆性破坏。2类试样的弹性能密度和应变能密度间有明确的线性关系，该关系不随组合试样中煤高度改变，也不随煤试样高度改变;组合试样中岩石的弹性能密度显著影响峰后煤样部分的破坏速度，由此可基于岩石弹性能密度变化判定组合煤岩冲击倾向性。该判定方法相比于传统“四指标”综合评价方法具有准确度高，操作简便，相关参数互相独立的特点。所得结果为进一步研究组合煤岩能量累积特征和冲击倾向性判定提供借鉴。

Uniaxial tests were performed on coal and coal-rock combinations to study the mechanical properties influenced by the height (portion) of coal,and the similarities and differences of two samples were analyzed on the strength,elastic modulus,fracturing feature and energy accumulation.The present work revealed the mechanical properties and energy accumulation rules considering effects of the height of coal,and a new assessment method was proposed to evaluate the bursting tendency of coal-rock combination.The results show that the elastic modulus of coal and coal-rock combination tend to be a constant with the height increase of coal.The strength of coal does not change with the height increases while the strength of combination samples decreases.The deformation of coal samples at peak stress is between 0.5-1.5 mm,and the fracturing feature changes from the semi-brittleness to plastic with the height of coal decrease.The fracture deformation of combination samples at peak stress is between 1-2 mm and the fracturing feature of combination samples is the brittle.Strain energy density is a linear function of elastic energy density and it does not change with the variation of coal height.The elastic-energy density of rock in combination samples has a significant effect on the failure of coal.Thus the bursting tendency of coal rock combination can be evaluated based on the elastic energy density of rock.Compared with the classical method “four index”,this method has some advantages,such as high accuracy,ease operating and independence of relevant parameters.The results provide theoretical support and experimental data for a further development of the energy accumulation feature of coal rock combinations.

1 试验系统及试验方案

   1.1 试验系统

   1.2 试样制备与试验方案

   1.3 试验步骤

2 组合煤岩的力学性质研究

   2.1 组合煤岩典型应力-应变曲线

   2.2 煤岩强度、弹性模量、破坏特征变化规律

   2.3 煤与组合煤岩变形破坏全过程分析

   2.4 组合煤岩应变能演化特征

   2.5 组合煤岩峰前弹性能密度与应变能密度关系

   2.6 基于岩石弹性能累积指数的组合煤岩冲击倾向性判定方法

3 讨论

4 结论