温度和层理对油页岩断裂韧度影响的试验研究  

Experimental Study on the Effect of Temperature and Bedding Planes on the Fracture Toughness of Oil Shale

作　　者：毕井龙 梁卫国[1,2] 耿毅德[1,2] 曹孟涛 黎力[1,2] Bi Jinglong;Liang Weiguo;Geng Yide;Cao Mengtao;Li li(Institute of Mining Technology,Taiyuan University of Technology,Taiyuan 030024,P.R.China;Key Laboratory of In-situ Property-improving Mining（Taiyuan University of Technology）,Ministry of Education,Taiyuan 030024,P.R.China)

机构地区：[1]太原理工大学采矿工艺研究所,太原030024 [2]太原理工大学原位改性采矿教育部重点实验室,太原030024

出　　处：《地下空间与工程学报》2018年第4期1007-1015,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家杰出青年科学基金(51225404);"三晋学者"支持计划资助项目(2013)

摘　　要：为了研究油页岩受不同温度影响的正交各向异性力学特征,以抚顺油页岩为研究对象,参照ISRM提出的半圆形弯曲试件测试脆性岩石Ⅰ型断裂韧度KIC的方法,利用万能材料试验机测试不同温度作用下的3种不同层理方向的油页岩试件的载荷和位移,计算得出KIC的变化规律。结果表明:在500℃以下,油页岩断裂表现出明显的脆性特征,在线弹性阶段,载荷-位移曲线的斜率与温度大致呈负相关;油页岩正交方向的断裂韧度存在各向异性;在150℃前,crack-arrester方位的断裂韧度大于crack-divider方位的断裂韧度,在200℃左右发生逆转,400℃以后二者趋于一致;常温下crack-splitter方位的值只有crack-arrester与crack-divider方位的1%~2%;不同层理方向的断裂韧度存在不同的"门槛"温度Tc,断裂韧度在Tc前后均呈现先增大后急剧减小的趋势。To research the orthogonal anisotropic mechanical characteristics of oil shale under the effect of different temperature,we use the method which proposed by ISRM to measure Mode I Static Fracture Toughness（ KIC）of semi-circular bend specimen. An experiment was conducted with Fushun oil shale,by using the universal testing machine to test the load and displacement of three different bedding planes under different temperature,and obtain the changing rules of KICby calculation. The result shows that： when the temperature is below 500 ℃,oil shale fractures show brittle fracture characteristics. During linear elasticity stage,it demonstrates a negative correlation between slope of the load-displacement curve and temperature. The KICof oil shale in the orthogonal directions is anisotropic. When test temperature is lower than 150 ℃,the KICof specimens of crack-arrester direction is greater than the KICof crack-divider direction. When test temperature is around 200 ℃,the crack-arrester direction KICof specimens is lesser than the crack-divider direction KIC. When test temperature is above 400 ℃,the results for these two types tend to be uniform with each other. The KICof crack-splitter direction is only 1% ~ 2% of crack-arrester direction and crack-divider direction. The KICof different bedding direction has different threshold temperature Tc,the value of KICpresents the tendency towards increasing first and then decreasing sharply before and after Tc.

关 键 词：油页岩 正交各向异性 层理 I型断裂韧度 门槛温度 

分 类 号：TU45[建筑科学—岩土工程]