Mechanical Properties and Damage Evolution Characteristics of Thermal Damage Basalt Under Triaxial Loading
Mechanical Properties and Damage Evolution Characteristics of Thermal Damage Basalt Under Triaxial Loading
复制标题
三轴加载下热损伤玄武岩的力学性能及损伤演化特征
DOI：
10.1007/s00603-023-03613-8
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发表时间：
2023-11
影响因子：
6.2
通讯作者：
Gang Wang;Leibo Song;Xiqi Liu;X. Ma;Jiaxing Qiao;Hao Chen;Longke Wu
中科院分区：
文献类型：
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作者：
Gang Wang;Leibo Song;Xiqi Liu;X. Ma;Jiaxing Qiao;Hao Chen;Longke Wu
为探索玄武岩在高温高压下的力学特性和损伤特征，对热损伤岩样进行了三轴压缩试验，利用CT图像重建和声发射技术对岩石从渐进损伤到宏观破坏的演化过程进行了跟踪和量化。结果表明：(1)随着温度的升高，玄武岩抗荷载和变形能力由轻微增强到迅速退化，600℃为其阈值；随着温度的升高，岩石的破坏模式逐渐由脆性向塑性转变，其峰后应力逐渐呈现一定的塑性流变特征。(2)随着温度的升高，玄武岩初始损伤变量led0呈现由低速发育到快速增长的阶段性特征。当温度超过400℃时，总损伤变量具有明显的先小增加后大变化的前兆特征，且随着温度的升高，该特征变得更加明显。(3)玄武岩主要矿物类型随温度的升高变化不大，但温度对部分组分的比例有一定影响。钙长石和顽辉石的比例呈现先减少后增加的变化趋势，安山石的演化则相反，其他矿物成分的比例基本不变。(4)温度阈值内玄武岩力学性能改善的主要原因是矿物颗粒的膨胀和围压的约束促进了内部原生裂缝的闭合，增加了密实性。而当玄武岩的热处理温度超过阈值时，热处理引起的结构劣化逐渐凸显，产生的缺陷对岩石的力学性能起主导作用。
To explore the mechanical properties and damage characteristics of basalt under high temperature and high pressure, triaxial compression tests are conducted on thermal damage rock samples, and the evolution process from progressive damage to macroscopic failure of rock is tracked and quantified by CT image reconstruction and acoustic emission technology. The results show that: (1) the ability of basalt to resist load and deformation changes from slight enhancement to rapid deterioration with the increase of temperature, and 600 ℃ is its threshold. The failure mode of rock gradually changes from brittleness to plasticity with the increase of temperature, and its post-peak stress gradually presents certain plastic flow characteristics. (2) With the increase of temperature, the initial damage variableD0of basalt presents a stage feature of changing from low-speed development to rapid growth. When the temperature exceeds 400 ℃, the total damage variableDwill have obvious precursor characteristic of small increase before the drastic change, and this characteristic will become more obvious with the increase of temperature. (3) The main mineral types of basalt hardly change with the increasing temperature, while the temperature has a certain influence on the proportion of some components. The proportion of anorthite and enstatite shows the changing trend of first decreasing and then increasing, while the evolution of andesine is opposite, and the proportion of other mineral components is basically unchanged. (4) The main reason for the improvement of mechanical properties of basalt within the temperature threshold is that the expansion of mineral particles and the constraint of confining pressure promote the closure of internal primary cracks and increase the compactness. However, when the heat treatment temperature of basalt exceeds the threshold value, the structural deterioration caused by heat treatment is gradually prominent, and the defects generated play a leading role in the mechanical properties of rock.