门头沟玄武岩细观矿物组成与宏观力学行为的关联性研究  

Investigation on the Relationship Between of Micro/meso Mineral Composition and Macro Mechanical Behavior of Moutougou Basalt

作　　者：左建平[1,2] 柴能斌[1] 赵灿 刘敏[1] 

机构地区：[1]中国矿业大学力学与建筑工程学院,北京100083 [2]山东科技大学山东省矿山灾害预防控制国家重点实验室培育基地,青岛266590

出　　处：《应用基础与工程科学学报》2015年第5期942-951,共10页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(51374215);霍英东教育基金会第十四届高等院校青年教师基金应用课题(142018);高等学校学科创新引智111计划(B14006);山东省矿山灾害预防控制国家重点实验室培育基地(山东科技大学)开放基金(MDPC2012KF03);北京市科委重大科技成果转化落地培育项目

摘　　要：把玄武岩视为硬质矿物和黏土质矿物两部分组成,提出了基于软-硬两部分的空间体积平均估算方法,估算的弹性模量与实验结果较为吻合.探讨了不同深度玄武岩矿物组成与宏观力学性质的关系,研究表明:高强度的矿物当含量较低时对整体力学性质的影响并不明显,只有含量超过某一门槛值后才有较大影响.如石英和斜长石强度都较高,但门头沟玄武岩石英含量低于15%时,石英含量在小范围的增加并不一定会导致岩石强度出现明显的提升;而当斜长石在42.5%—49.2%之间发生变化时,含量增加导致弹性模量和单轴抗压强度有明显增加的趋势.随着埋深增加,门头沟玄武岩中黏土质矿物含量在不断减小,而软弱黏土质矿物含量的减少,明显导致玄武岩的宏观力学行为的显著变化,这是深部岩石与浅部岩石的破坏机理及强度特性存在差异的一个重要原因.Based on space-volume average method in the literature,we estimate elastic modulus of basalt from different depths. However,there are great difference between theoretical value and experimental values. In this paper,basalt is regarded as hard part and soft part based on X-ray analysis results. Subsequently,a new soft-hard two parts spatial volume average estimation method was proposed. These results indicated that the estimate elastic modulus was more consistent with the experimental results and the literature. The relationship between macroscopic mechanical behavior and micro/meso mineral composition has been discussed in detail.Theoretical analysis indicated aslo that the overall mechanical properties are obviously not changed when the content of high-strength mineral is low. And only when the content exceeds a certain critical value,the strength will greatly change. Though the strength of quartz and plagioclase is high,basalt strength does not increase greatly since the content of quartz in Mentougou basalt is less than 15%. However,when the content of plagioclase changes between42. 5% —49. 2%,the elastic modulus and uniaxial compressive strength greatly increase with the increasing of plagioclase content. With the increasing of depth,the clay mineral content of Mentougou basalt gradually decrease. However,with the decreasing of clay mineral,the macroscopic mechanical behavior and failure strength of basalt significantly increase. The above reasons are the nature difference of failure mechanism and strength characteristic between shallow and deep rock.

关 键 词：玄武岩 矿物组成 宏观力学行为 宏细观关联性 黏土矿物 

分 类 号：TU45[建筑科学—岩土工程]