第三章_岩石的力学性质.pptx

1、流变的概念/Concept of Rheology 2、典型的蠕变曲线/Typical Curve of Creep of Rock 3、岩石的蠕变的类型/Types of Creep of Rock 4、岩石蠕变的影响因素/Factors Influencing on Creep of Rock 5、岩石的流变力学模型/Creep Mechanical Models of Rock 1 Chapter 3 Mechanical Properties of Rock 3.3 岩石的变形特性/ Deformability of Rock 3.3.4 岩石的流变特性/ Rheology of Rock Tang Lizhong . Institute of Rock Soil Mechanics and Engineering, Central South University 2 Chapter 3 Mechanical Properties of Rock 3.3 岩石的变形特性/ Deformability of Rock Tang Lizhong . Institute of Rock Soil Mechanics and Engineering, Central South University 3.3.4 岩石的流变特性/ Rheology of Rock 1、流变的概念 流变：应力应变随时间变化的特性 蠕变：当应力保持不变，应变随时间而增大的特性 松驰：当应变保持不变，而应力随时间减小的特性 ——与时间相关的特性/时间相依性/Time-dependent Behaviour 3 Chapter 3 Mechanical Properties of Rock 3.3 岩石的变形特性/ Deformability of Rock Tang Lizhong . Institute of Rock Soil Mechanics and Engineering, Central South University 弹性后效：卸荷后，岩石具有随时间的增长应变逐渐恢复的特性 3.3.4 岩石的流变特性/ Rheology of Rock 2、典型的蠕变曲线/Typical Curve of Creep of Rock a）AB阶段，瞬态蠕变（减速蠕变）阶段，产 生的应变可以完全恢复。 蠕变阶段: b）BC阶段，稳定蠕变（等速蠕变）阶段，应变率为常数， c）C点以后阶段，非稳态蠕变（加速蠕变），阶段，应变率逐渐增大 4 类型Ⅱ：不稳定蠕变(unstable creep) 加速蠕变,蠕变最终导致破坏 类型Ⅰ：稳定蠕变(stable creep） 蠕变曲线只包含瞬态蠕变段和稳态蠕变段 雪花石膏在水中的蠕变 （据Griggs，1940） Chapter 3 Mechanical Properties of Rock 3.3 岩石的变形特性/ Deformability of Rock Tang Lizhong . Institute of Rock Soil Mechanics and Engineering, Central South University 3.3.4 岩石的流变特性/ Rheology of Rock 3、岩石的蠕变的类型/Types of Creep of Rock 蠕变类型: 5 Chapter 3 Mechanical Properties of Rock 3.3 岩石的变形特性/ Deformability of Rock Tang Lizhong . Institute of Rock Soil Mechanics and Engineering, Central South University 1）应力水平 a.低应力水平下不出现非稳态 蠕变阶段 b.中等应力水平下完整蠕变曲 线 c.高应力水平下很快破坏 长期强度/long-term strength 使岩石由稳定蠕变转化为不稳定蠕变的恒定应力 3.3.4 岩石的流变特性/ Rheology of Rock 4、岩石蠕变的影响因素/Factors Influencing on Creep of Rock 6 Chapter 3 Mechanical Properties of Rock 3.3 岩石的变形特性/ Deformability of Rock Tang Lizhong . Institute of Rock Soil Mechanics an