荷载作用下磷块岩晶界裂纹产生扩展贯通破坏机理研究

项目名称： 荷载作用下磷块岩晶界裂纹产生扩展贯通破坏机理研究

项目编号： No.51474159

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 矿业工程

项目作者： 张电吉

作者单位： 武汉工程大学

项目金额： 82万元

中文摘要： 白云质条带状构造磷矿石是我国磷块岩矿主体，在其地下开采过程中，采场顶板、边帮及矿柱裂纹的产生扩展破坏，常引起采场的不稳定并导致灾难性事故发生，而条带状磷块岩中不同晶界起裂以及裂纹的扩展贯通是引起磷块岩变形破坏的关键。选取具有代表性的磷块岩，将磷块岩中胶磷矿、白云石以及含胶磷矿与白云石接触晶界的部位分别加工成试样，借助加载下实时观测的 SEM实验系统，对载荷作用下磷块岩中不同类型晶界起裂及裂纹扩展规律进行室内实验。根据试样中裂纹的 SEM 图像，借助数字图像处理的方法，分析研究晶界的开裂及裂纹传播规律。通过对三种不同类型晶界在应力作用下的起裂破坏实验研究及理论分析，从能量耗散及释放的理论出发，确定出在应力作用下最先起裂的晶界类型，该晶界就是磷块岩开裂破坏的最弱部位，以此为基础，采用断裂力学及损伤力学相关理论，建立在荷载作用下磷块岩晶界裂纹产生扩展贯通破坏力学模型。

中文关键词： 磷块岩；晶界；裂纹扩展；能量耗散；破坏机理

英文摘要： The dolomitic banded structure phosphor ore is the main phosphorite body in China. The crack propagation in stope roof and pillar often causes the instability of stope in underground mining，and disasters will take place because of the crack propagation in the underground Phosphorite mine. The main reason of causing phosphorite destruction is the crack propagation in different kinds of banded Phosphorite grain boundary.Selecting the typical phosphorite sample,three types of test samples(collophanite, dolomite and mixing grain boundary of collophanite and dolomite) will be taken. The crack propagation in different types of Phosphorite grain boundary will be tested by using real time observation SEM experimental system. Based on the crack SEM image, the grain boundary crack propagation will be analyzed by using digital image processing method.Through experimental study and theoretical analysis for three different types of grain boundary fracture, the first fractured grain boundary can be determined by using energy dissipation and energy release theory , the first fractured grain boundary is the weakest parts of the Phosphorite. Based on the fracture and damage mechanics theory，the mechanical model of phosphorite grain boundary crack propagation and failure will be set up .

英文关键词： phosphorite;grain boundary;crack propagation;energy dissipation;failure mechanism