温度作用下花岗岩力学性质实验研究  

Experimental research on mechanical characteristics of granite under temperature loads

作　　者：徐小丽[1,2] 高峰[2] 钟卫平[2] 王美芬[3] 

机构地区：[1]南通大学建筑工程学院,江苏南通226019 [2]中国矿业大学理学院,江苏徐州221008 [3]燕山大学建筑工程与力学学院,河北秦皇岛066004

出　　处：《西安科技大学学报》2008年第4期651-656,共6页Journal of Xi’an University of Science and Technology

基　　金：973国家重点基础研究发展规划项目(2002CB412705;2002CB412707);国家创新群体项目(50221402);国家自然科学基金项目(50579042)

摘　　要：对实时高温作用下(常温～850℃)和高温作用冷却后(常温～1300℃)花岗岩试件单轴受压破坏全过程进行了试验研究,得到了实时高温作用下花岗岩的全应力-应变曲线、高温作用冷却后岩石破坏全过程的力学特征和声发射特征。试验结果表明:实时高温作用下,花岗岩强度等力学性质连续劣化;高温作用冷却后,花岗岩在200℃～600℃的温度区间内出现了一个随温度升高强度不降反增的异常现象,在850℃之后,岩样强度降低,呈现出较明显的塑性特征,花岗岩结构发生脆塑性转变的相变行为;岩样承受900℃以上高温作用后,声发射信号强度降低,持续时间增长,尤其在峰值强度之后,残余塑性变形释放出较密集的声发射信号。随着岩样所受温度的升高,出现突发密集声发射信号的时间点延迟。Experiments on granite under uniaxial compression at high temperature （ normal - 850℃） and after high temperature （ normal - 1 300℃） have been researched. The stress-strain behaviors at high temperature and mechanical characteristics, acoustic emission （AE）characteristics after high temperature have been obtained. The results show that at high temperature peak strength decreases continuously. But after high temperature , there is an excrescent phenomenon that strength increases with the rising of temperature from 200 ℃to 600 ℃. The strength decreases suddenly and the granite presents plastic behavior after 850℃, which indicates phase change behavior of brittle-ductile transition has appeared around 850℃. After 900 ℃, the granite presents plastic behavior, AE strength decreases, the duration increases and the residual plastic deformation of granite still releases serried acoustic emission especially after peak strength. The time that AE counts appear obviously has been postponed with the increase of temperature.

关 键 词：花岗岩 温度载荷 应力应变曲线 声发射 脆塑性转换 

分 类 号：TD315[矿业工程—矿井建设]