Creep Damage Characteristics of Soft Rock under Disturbance Loads

This article focuses on the process of rock creep damage and micro-damage evolution properties of gray green mudstone under impacting disturbance load conditions for the first time using the real time computerized tomography (CT) testing technique. The results indicate that axial load comes into limit strength neighborhood, rock micro-crack links into larger crack, creep rate increases in a short time, larger plastic deformation happens; this is called disturbance accelerating creep stage. When rock is within limit strength neighborhood, there occurs creep micro-damage under smaller disturbance load. When disturbance load is larger, rock directly enters into disturbance accelerating creep stage, failure occurs instantaneously. On the basis of experimental research, the CT scanning method was used to describe the creep micro-damage of soft rock, also helpful in the prediction of roadways' service life and evaluation of geotechnicai engineering stability.     

岩石点荷载强度与单轴抗压强度线性关系试验

针对目前岩石点荷载试验大部分采用规则试件进行,试件加工制作及试验的过程繁琐、成本高的问题,通过自制点荷载试验仪以及RMT-150B岩石力学伺服试验机,对煤矿顶底板常见岩性进行不规则岩石试件点荷载试验和规则岩石试件单轴抗压试验。试验结果表明:不规则岩石点荷载强度基本上满足正态分布规律,同时,点荷载破坏载荷与破坏面积之间呈线性关系,不同载荷破坏面积对点荷载试验中的尺寸、形状效应基本上没有太大的影响。通过分析点荷载强度与单轴抗压强度两者间的关系,得出通过点荷载强度确定单轴抗压强度的经验公式。      

全预应力锚杆机械锚固装置的设计与应用

针对目前地下工程中广泛使用的螺纹钢锚杆支护存在的预紧力差、预应力长度短的问题，设计制造了全预应力螺纹钢锚杆机械锚固装置，有效加大了锚杆预应力段的长度，提高了锚杆的预紧力，解决了施工锚杆后因爆破震动或矿压显现造成的托盘反复松动问题。现场应用和矿压观测表明，全预应力锚杆支护能适应恶劣条件，有效控制围岩的变形。