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基于微观机理的高温后大理岩动态力学特性分析
- 作者：
- 宋世兴
- 作者单位：
- 中铁二十五局集团第二工程有限公司
基金项目：
- 国家自然科学基金项目（11862010）
详细信息：
- 作者简介：
- 宋世兴(1977—)，男，高级工程师，从事施工技术及企业管理工作；E-mail：ht1421831377@126.com
- 通讯作者：
- isnull
- PDF下载
Analysis of the dynamic mechanical properties of marble after high-temperature exposure based on microscopic mechanisms
- English Author：
- 2th Engineering Co.,Ltd.,China Railway 25th Bureau Group Corporation
- Unit：
- 摘要
- 在线预览
- 参考文献
摘要:
为研究温度对大理岩动态力学特性的影响，对常温（25 ℃）及高温（200 ℃、400 ℃、600 ℃和800 ℃）后的大理岩试样开展SHPB试验、XRD和SEM微观试验，探究了高温后大理岩动态力学特性与温度的关系及微观损伤机理。结果表明：高温后大理岩的动态压缩应力-应变曲线分为弹性、屈服、破坏3个阶段；大理岩的峰值应力及破坏特征均存在明显的温度效应，即随温度的升高，大理岩的峰值应力逐渐下降，破碎程度加剧；大理岩的动态力学特性与其矿物组分及晶体结构密切相关，200 ℃~600 ℃时，微缺陷增多，且白云石发生了热分解转化，在800 ℃时，矿物分解生成CO2气体和氢氧化钙，且晶体结构发生熔融破坏，内部损伤严重，塑性增强，从而导致宏观力学特性的大幅下降。
关键词:
深部开采；大理岩；高温作用；微观损伤机理；动态力学特性；动态压缩试验
Abstract:
To study the effect of temperature on the dynamic mechanical properties of marble,dynamic compression tests,XRD,and SEM microscopic tests were conducted on marble samples at room temperature (25 ℃) and after exposure to high temperatures (200 ℃,400 ℃,600 ℃,and 800 ℃).The relationship between the dynamic mechanical properties of marble and temperature,as well as the microscopic damage mechanisms,were explored.The results show that the dynamic compressive stress-strain curves of marble after high-temperature exposure can be pided into 3 stages:elastic,yield,and failure.The peak stress and failure characteristics of marble exhibit a significant temperature effect:as the temperature increases,the peak stress of marble gradually decreases,and the degree of fragmentation intensifies.The dynamic mechanical properties of marble are closely related to its mineral composition and crystal structure.Between 200 ℃ and 600 ℃,micro-defects increase,and dolomite undergoes thermal decomposition and transformation.At 800 ℃,mineral decomposition produces CO2 gas and calcium hydroxide,and the crystal structure undergoes melting damage,leading to severe internal damage and increased plasticity,resulting in a substantial decline in macroscopic mechanical properties.
Keywords:
deep mining;marble;high-temperature effect;microscopic damage mechanism;dynamic mechanical property;dynamic compression test