摘要
针对寒区节理岩体工程结构中的冻融受荷岩体,采用在类岩石材料中预制裂隙的方法模拟节理岩体,通过冻融循环试验和单轴压缩试验,分析裂隙岩样的几何特征(裂隙长度、裂隙倾角)对岩体强度的影响;基于细观损伤理论和宏观统计损伤模型,建立冻融受荷裂隙岩石损伤劣化模型,探讨裂隙岩体在冻融和荷载耦合作用下的损伤劣化机制。研究结果表明:(1)岩石反复冻融引起的损伤是一个疲劳破坏的过程,受荷损伤是岩石类非均质材料各组成成分对力的传递速率以及自身变形差异性引起应力场不均匀分布的过程;(2)冻融和受荷以不同的力学机制促使岩石中裂纹的萌生和扩展,由此诱发的损伤相互耦合,其耦合作用会使总损伤有所劣化;(3)裂隙长度以及冻融循环次数对总损伤的影响较大,而裂隙倾角对总损伤的影响相对较小;(4)相同的冻融循环次数下,裂隙岩样较完整岩样的损伤劣化程度严重。
For rock masses under freeze-thaw and loading in engineering structures in cold regions, using rock-like materials produced rock specimens with different geometric characteristics, based on the freeze-thaw experiments and uniaxial compression test, the influence of crack dip angle and crack length on the rock masses strength were studied; and combining mesoscopic damage theory and macroscopic statistical damage model, the damage model of freeze-thaw and loading rock masses were established; at the same time, damage degradation mechanism of jointed rock masses under the coupling action of freeze-thaw and loading were discussed. The research results show that： （1） The freeze-thaw damage is a process of fatigue damage; and loading damage is an uneven distribution process of stress field and deformation. （2） Freeze-thaw and loading with different mechanisms promote rock crack initiation and propagation; hence induced damages couple with each other, the coupling of the two will make the total damage deterioration. （3） Crack length and freeze-thaw cycles on total damage is larger; the influence of crack dip angle on the total damage is relatively small. （4） under the same cycles of freeze-thaw, damage degradation of cracking rocks is more serious than the intact samples.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2013年第11期2307-2315,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51274157)
中央高校基本科研业务费专项资金资助(2013–II–012)
湖北工程学院校级项目(Z2013005)
关键词
岩石力学
冻融
单轴压缩
耦合作用
裂隙岩体
损伤演化模型
rock mechanics
freeze-thaw
uniaxial compression
coupling effect
jointed rock masses
damageevolution model
