冲击荷载作用下砂岩的高温动态力学性能研究

发布时间：2018-05-24 15:50

  本文选题：砂岩 + 高温　； 参考：《安徽理工大学》2017年硕士论文

【摘要】：随着深部煤矿的不断开采,遇到各种复杂的地质环境,深部岩体的力学行为已经成为一个关乎民生大计的重要课题,也将是未来岩体力学研究的热点及重点领域之一。另外,在能源、地质、土建等其他关乎民生大计的地方,例如核废料的深层埋置、石油及天然气的地下开采及存储以及地热资源的开发与利用等都涉及到高温下岩石的力学特征。因此,研究高温下岩石的力学性质,特别是高温下岩石的动态力学性能,将会对今后的工程实践与理论研究产生巨大的意义。本文通过SHPB高温实验装置对不同温度下的煤矿深部砂岩进行了动态冲击压缩实验及动态劈裂拉伸实验,分析了砂岩峰值应力随温度变化的规律以及砂岩的破坏情况,研究了砂岩的动态力学特性;同时对不同温度的砂岩岩样进行SEM和XRD实验,观察了试样的断口形貌,分析了岩样的组成成分。主要研究内容和成果如下:(1)在常温(20℃)～700℃下对砂岩进行0.3MPa、0.5MPa和0.7MPa三种冲击气压下的动态单轴压缩实验,分析了砂岩峰值应力随温度变化的规律,随温度的变化砂岩的峰值应力大致经历平缓-上升-下降三个过程。从试件的破碎情况图中也可看出,每种温度类别下,随着冲击气压的增大,砂岩的破碎程度也加大,由完整的短圆柱体破坏为块状或粉状。(2)在常温(20℃)～700℃下对砂岩进行0.3MPa、0.5MPa和0.7MPa三种冲击气压下的动态劈裂拉伸实验,得出随着温度的上升,砂岩的峰值抗拉强度表现出由上升到下降的过程;随着冲击气压的增大,砂岩试件的应变率也在增大,在时间为50～300μs应变率形成一段较为平稳的平台。(3)对砂岩岩样进行SEM和XRD实验,观察了试样的断口形貌,分析了岩样的组成成分,分析了砂岩成分随温度的变化情况,得到砂岩岩样在温度—应力共同作用下的裂纹扩展规律。
[Abstract]:With the continuous exploitation of deep coal mines and various complicated geological environments, the mechanical behavior of deep rock mass has become an important issue related to the livelihood of the people, and will also be one of the hotspots and key areas of rock mechanics research in the future. In addition, in energy, geology, civil engineering and other places of great concern to people's livelihood, such as the deep burial of nuclear waste, The underground exploitation and storage of oil and natural gas and the exploitation and utilization of geothermal resources are all related to the mechanical characteristics of rocks at high temperature. Therefore, studying the mechanical properties of rocks at high temperature, especially the dynamic mechanical properties of rocks at high temperature, will be of great significance to the engineering practice and theoretical research in the future. In this paper, the dynamic impact compression test and dynamic splitting tensile test of deep sandstone in coal mine at different temperatures are carried out by using SHPB high temperature experimental device. The law of the change of peak stress of sandstone with temperature and the failure of sandstone are analyzed. The dynamic mechanical properties of sandstone were studied, and the SEM and XRD experiments of sandstone rock samples at different temperatures were carried out. The fracture morphology of the samples was observed and the composition of rock samples was analyzed. The main research contents and results are as follows: (1) dynamic uniaxial compression experiments of sandstone under 0.3 MPA and 0.7MPa impact pressure at 20 鈩，

本文编号：1929650