摘要
为深入探究土石混合料的电阻率特性,采用改装的三轴仪对土石混合料进行三轴固结排水剪试验,同步测量电阻率的变化,获得土石混合料固结与剪切全过程中电阻率的变化规律及剪切强度特性对电阻率的影响,分析土石混合料的应力-应变曲线,建立电阻率与体应变之间的理论关系。结果表明:土石混合料的电阻率在固结及剪切全过程都呈递减趋势,降低速率都表现为先快后慢;不同于传统岩石,土石混合料的应力-应变曲线具有其独特性;土石混合料电阻率与其剪切强度、黏聚力和内摩擦角呈负相关性;试验围压对电阻率有影响;在三轴剪切过程中,电阻率随着轴向应变的增加呈先快速降低后缓慢减小的变化规律;理论分析可知体应变的变化会导致土石混合料电阻率的改变。微观结构的改变是引起电阻率变化的根本原因本文研究成果,有助于从细观层面加强对电阻率特性的理解。
In order to further study the electrical resistivity change characteristics of soil-rock mixture,a modified triaxial apparatus was used to conduct consolidated drained test on soil-rock mixture samples,and the changes in resistivity are measured simultaneously to obtain the electrical resistivity variation regularities during the whole consolidation and shear process of soil-rock mixture and the effect of shear strength characteristics on electrical resistivity.The stress-strain curves of soil-rock mixture and the theoretical relationship between electrical resistivity and volume strain are analyzed and established.The results show that:The electrical resistivity of soil-rock mixture in the whole consolidation and shear process is decreasing trend,and its reduction rate is first fast and then slow.Unlike conventional rocks,the stress-strain curve of soil-rock mixture has its own peculiarities.The electrical resistivity of soil-rock mixture is found to decrease with the increase of shear strength,cohesion and internal friction angle.The test confining pressure has an effect on the electrical resistivity.During the triaxial shear process,the electrical resistivity variation regularities show a rapid decrease trend with the increase of axial strain,followed by a slow decrease.Theoretical analysis shows that the change in volume strain leads to the electrical resistivity variation of soil-rock mixture.Changes in microstructure are the fundamental cause of electrical resistivity variations,which is helpful to enhance the understanding of electrical resistivity properties from the meso-level.
作者
陈松林
赵明阶
汪魁
Chen Songlin;Zhao Mingjie;Wang Kui(Engineering Research Center of Diagnosis Technology and Instruments of Hydro-Construction,Chongqing Jiaotong University,Chongqing 400074,P.R.China;School of Civil Engineering and Architecture,Chongqing University of Science and Technology,Chongqing 401331,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2023年第6期1859-1869,1906,共12页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51879017)。
关键词
土石混合料
电阻率
强度特性
三轴试验
理论关系
soil-rock mixture
electrical resistivity
strength characteristics
triaxial test
theoretical relationship
