基于逾渗模型的盐岩损伤与破坏研究  

Study of salt rock damage and failure based on percolation model

作　　者：孙中秋[1,2] 谢凌志[1,2] 刘建锋[1,3] 何柏[1,2] 

机构地区：[1]四川大学能源工程安全与灾害力学教育部重点实验室,成都610065 [2]四川大学建筑与环境学院,成都610065 [3]四川大学水利水电学院,成都610065

出　　处：《岩土力学》2014年第2期441-448,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金委国际(地区)合作交流项目(No.51120145001);国家自然科学基金委青年基金项目(No.51104102)

摘　　要：逾渗是一种分形模型,利用声发射点定位盐岩内部破坏网格来建立逾渗模型,可以分析三轴压缩条件下盐岩逾渗特征以及损伤演变发展。研究发现,各试样逾渗模型团簇(cluster)数与最大团簇占有率关系曲线斜率在70%应力峰值后基本相等,利用最大团簇沿试样轴向的延伸来描述裂缝的扩展规律,并通过最大团簇在轴向的延伸终点得到了各试样逾渗的临界破坏比率,它对于研究渗透陡增点非常重要。提出利用逾渗关联长度(关联长度?代表处于同一团簇中的两个点的平均距离)确定试样损伤起始点,并通过计算逾渗模型破坏比率得到损伤变量,它和基于AE振铃计数以及AE能量计算得到的损伤变量结果相近。研究结果表明,逾渗可以形象地表述岩石内部破裂过程和损伤情况,为研究岩石破坏失效及裂缝衍生发展提供了新的思路。As a fractal model, percolation method can analyze salt rock failure process and damage evolution under triaxial compression by creating a percolation model to locate the salt rock failure grid by using acoustic emission （AE）. Percolation model shows that the slope of relationship curves between cluster number and the largest cluster occupancy for each specimen percolation model is basically equal after 70% of peak stress. The extension of the largest cluster along the specimen axially agrees with the evolution of cracks;and the critical failure probability is determined by the end of the largest cluster in axial direction, which is very important for the study of the sharply increased permeability point. The starting point of damage is determined by the correlation length of percolation, the average distance between two points in the same clusters, and the damage factor is calculated by percolation model failure probability which is accordance with the damage factor calculated according to AE parameters such as AE count numbers or AE energy . The research results show that percolation is a promising method to describe rock failure process and damage status so as to provide a novel approach for studying the rock failure and its cracks propagation.

关 键 词：盐岩 逾渗 损伤 裂缝 声发射 关联长度 ACOUSTIC EMISSION (AE) 

分 类 号：TU451[建筑科学—岩土工程]