摘要
通过三点弯曲试验,利用CCD相机作为观测手段,采用数字散斑相关方法,对一种细砂岩组成的层状复合岩石试件进行试验研究,分析层状复合岩石变形破坏全过程接触面力学特征。结果表明:(1)随着荷载的施加,上下层试件表面的水平应变场呈现竖向分布的拉压应变区交替出现的现象,这种现象在层间接触面附近尤为明显;(2)层间滑动位移整体呈波动状态分布,随着荷载的增加,层间滑动位移值逐步增大,最大滑移值为0.174mm;(3)接触面水平应力值受层间接触条件影响呈波动变化状态,层间竖向应力曲线呈V形分布;(4)加载过程中层间摩擦系数不断变化,在滑动初期阶段,摩擦系数从3.5降低至0.2,在稳定滑动阶段,摩擦系数则保持为0.15;(5)上下层面变形能密度曲线变化趋势基本相同,在荷载峰值时刻,接触面变形能密度达到最大值4.2 J/m^(3)。上述研究成果可为远程岩层界面DIC监测和岩层滑动研究取值提供有益的参考。
Three-point bending tests were conducted on laminated composite rock specimens composed of fine sandstone.A CCD camera was used for observation and a digital speckle correlation method was adopted.The mechanical characteristics of the contact surface were analyzed during the whole process of deformation and damage of the laminated composite rock.The results are as follows.(1)With the application of load,the horizontal strain fields on the surfaces of the upper and lower specimens show alternating tensile and compressive strain zones with vertical distribution,and this phenomenon is especially obvious near the interlaminar contact surface.(2)The overall interlayer sliding displacement was fluctuating.The value of interlayer sliding displacement gradually increased with a maximal slip value of 0.174 mm as the load increased.(3)The value of horizontal stress on the contact surface fluctuated due to varying interlayer contact condition.The vertical stress curve between layers was“V”shaped distribution.(4)The interlayer friction coefficient changed continuously during the loading process,and it reduced from 3.5 to 0.2 in the early sliding stage,and remained at 0.15 in the stable sliding stage.(5)The deformation energy density curves of the upper and lower layers have the same trend,and the contact surface deformation energy density reached the maximum value of 4.2 J/m^(3)at the peak loading moment.The above research results can provide useful reference for remote rock interface DIC monitoring and rock sliding study taking values.
作者
许海亮
谭安福
宋义敏
朱力
安栋
杜羽
高晗钧
XU Hai-liang;TAN An-fu;SONG Yi-min;ZHU Li;AN Dong;DU Yu;GAO Han-jun(School of Civil Engineering,North China University of Technology,Beijing 100144,China;CCCC Second Public Administration Engineering Design and Research Institute,Xi’an,Shaanxi 710065,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第6期1683-1694,共12页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51474013)。
关键词
层状复合岩石
三点弯曲试验
接触面
力学特征
laminated composite rocks
three-point bending test
contact surface
mechanical characteristics
