摘要
基岩与其上的混凝土结构组成的一体两介质结构的力学性能直接影响到上部工程结构安全性与可靠性。为了探讨岩石混凝土一体两介质结构在干燥与饱水状态下的损伤力学行为,开展了干燥与饱水状态下岩石、混凝土和岩石混凝土一体两介质三种材料在单轴荷载条件下声发射试验研究。根据声发射事件数表征损伤变量与本构关系,对比分析了岩石混凝土一体两介质材料的变形、损伤破坏特征。结果表明:干燥与饱水状态下三种结构的声发射特性大体相似,可按材料变形将声发射事件分成压密阶段、弹性阶段、塑性阶段和破坏阶段。在压密与弹性阶段,干燥一体两介质结构声发射特征与岩石类似,撞击数出现小幅阶跃现象,声发射能量极少甚至没有,饱水一体两介质结构撞击数很少且没有出现明显的阶跃现象,声发射能量与干燥状态下一致;在塑性与破坏阶段,干燥一体两介质结构撞击数随着应力增大而逐渐增加,声发射特征与混凝土相似,并且撞击数峰值介于构成其结构的两种材料之间。饱水一体两介质结构撞击数峰值相比应力峰值稍稍滞后一点,一体两介质结构没有出现明显的脆性而是偏延性破坏,其声发射撞击数与能量计数出现两个单峰,分别对应着两次大的破坏;三种材料的声发射撞击数峰值与能量计数峰值相比于应力峰值具有滞后现象。
The mechanical properties of the bi-material structure composed of bedrock and its concrete structure directly affects the safety and reliability of the superstructure.In order to investigate the damage mechanics behavior of bi-material structure of rock-concrete under dry and saturated states,the acoustic emission test under uniaxial load was carried out.According to the number of acoustic emission events reveals the damage variable and constitutive relationship,the deformation and damage characteristics of bi-material of rock-concrete were compared and analyzed.The results show that the acoustic emission characteristics of three structures are generally similar under conditions of the drying and water saturation.There are four stages for acoustic emission events according to the material deformation,such as compaction stage,elastic stage,plastic stage and failure stage.In the stage of compaction and elasticity,the acoustic emission characteristic of the bi-material structure is in the dry similar to rocks,the number of impact was small and the acoustic emission energy is very little or not.While the number of acoustic emission impact of the saturated state is few and no obvious jump phenomenon appeared,and the acoustic emission energy is in accordance with the dry state.The number of acoustic emission impact of the bimaterial structure is in the dry increases gradually with increasing stress,the acoustic emission characteristics is similar to the concrete,the acoustic emission characteristics are similar to those of concrete,and the peak number of impacts is in two materials constituting the structure.The peak for the number of acoustic emission impact of the bi-material structure is in the saturated state is slightly delayed compared with the peak of the stress,and the bi-material structure has no obvious brittleness but a metamorphic damage,and appeare two single peaks,which correspond to two great damage phenomena respectively.Compared with the peak of energy counting,the peak of acoustic emission impact num
作者
孙冰
刘涵
袁登
王富林
曾晟
SUN Bing;LIU Han;YUAN Deng;WANG Fu-lin;ZENG Sheng(School of Civil Engineering,University of South China,Hengyang 421001,China;Railway Company of Zhejiang Communication Construction Group Co.,Ltd.,Hangzhou 310003,China;School of Resource & Environment and Safety Engineering,University of South China,Hengyang 421001,China)
出处
《硅酸盐通报》
CAS
北大核心
2019年第2期482-487,共6页
Bulletin of the Chinese Ceramic Society
基金
湖南省自然科学基金面上项目(2018JJ2331)
关键词
岩石地基
混凝土结构
一体两介质
声发射
损伤特征
rock foundation
concrete structure
uni-body bi-material specimen
acoustic emission
damage characteristic
