The book starts, in Chapter 1, with an overview of the current status of geomechanical model tests and infrared detection, followed by an introduction to some theoretical aspects of infrared physics and algorithms used in the infrared image processing (Chapter 2). Geomechanical model construction is presented in Chapter 3. In Chapters 4, 5, 6, 7 and 8, application of infrared thermography in the geomechanical model tests on tunnel excavations and roadway stability assessments in differently inclined rock strata are presented respectively with a detailed description of the experimental methods, testing procedures, imaging processing algorithms and findings obtained from characterization of the thermal sequences. The intended readers may fall into three groups. The first group is the undergraduate science maior students who may want to learn in depth about the topic of this book. In this case, the publication can complement an advanced text
Table of Contents
Preface Chapter 1 Overview 1.1 Background 1.2 Overview of geomechanics model tests 1.3 Overview of infrared detection References Chapter 2 Theoretical aspects of theinfrared 2.1 The infrared 2.2 Infrared spectralband 2.3 Radiometry fundamentals 2.3.1 Radiant energy 2.3.2 Radiant power and flux 2.3.3 Geometrical spreading of a beam 2.3.4 Radiance 2.3.5 Irradiance 2.3.6 Radiant exitance 2.3.7 Radiant intensity of a source in a given direction 2.3.8 Bouguer's law 2.3.9 Radiation scattering 2.4 Black body radiation 2.4.1 Concept of black body 2.4.2 Planck's law 2.4.3 Wien'slaw 2.4.4 Stefan—Boltzmann law 2.4.5 Exitance of a black body in a given spectral band 2.4.6 Calculation of exitance of black body 2.4.7 Thermal radiation contrast 2.5 Radiation of real bodies 2.5.1 Different types of radiator 2.5.2 Emissivity of a material 2.5.3 Stefan—Boltzmann—s law for grey body 2.5.4 Dielectric materials 2.5.5 Electrically conducting materials References Chapter 3 Geomechanical model test 3.1 Literature review on physical model test 3.2 Similarity theory and dimensional analysis 3.2.1 Similarity principles 3.2.2 Selection of similarity materials and ratios 3.3 Field case （prototype） 3.3.1 Site geology 3.3.2 In situ rock properties 3.4 Geomechanical model construction 3.4.1 Testing machine 3.4.2 Model dimension 3.4.3 Physico—mechanical parameters of the model 3.4.4 Rock structure simulation 3.4.5 Geomechanical model 3.5 Infrared detection 3.5.1 Thermography and imaging procedures 3.5.2 Temperature calibration 3.5.3 Image processing References Chapter 4 Excavation in 60° inclined strata 4.1 Introduction 4.2 Experiment 4.2.1 Rock model material 4.2.2 Geomechanical model construction 4.2.3 Excavation plan 4.2.4 Excavation method 4.3 Infrared detection 4.3.1 Infrared thermography 4.3.2 Thermal—mechanical coupling 4.4 Image processing 4.4.1 Problem statement 4.4.2 Algorithms 4.4.3 Processing and assessment 4.5 Image analysis 4.5.1 Extracting the energy release index 4.5.2 Spectral characterization 4.5.3 Principles for image analysis 4.6 Experimental results 4.6.1 Overall thermal response 4.6.2 Heat sources and thermal conduction 4.6.3 Characterization of the full—face excavation 4.6.4 Heat production mechanism in the staged excavation 4.6.5 Characterization of the staged excavation 4.7 Discussion 4.7.1 Excavation in differently inclined rocks over full—face excavation 4.7.2 Excavation in differently inclined rocks over the staged excavation 4.7.3 Sununary References Chapter 5 Excavationin 45°strata 5.1 Introduction 5.2 Short review of infrared detection 5.3 Experiment 5.3.1 Model construction 5.3.2 Testing procedure 5.4 Infrared detection 5.4.1 Infrared thermography 5.4.2 Energy release index 5.4.3 Image processing algorithm 5.4.4 Principles for image analysis 5.4.5 Fourier analysis 5.5 Results and Discussions 5.5.1 Overall thermal response 5.5.2 Characterization of the full—face excavation 5.5.3 Comparison between the excavation in 0° and 45° inclined strata 5.5.4 Characterization of the staged excavation 5.5.5 Summary Chapter6 Excavation in horizontal strata 6.1 Introduction 6.2 Experiment 6.2.1 Geomechanical model construction 6.3 Infrared detection 6.3.3 Fourier transform of the thermal image 6.3.4 Enhancement of the thermalimage 6.3.5 Spectral analysis 6.4 Results and discussions 6.4.1 Overall thermal response 6.4.2 Characterization of the full—face excavation 6.4.3 Characterization of the staged excavation 6.4.4 Summary References Chapter 7 Overloaded tunnelin 45° inclined rocks 7.1 Introduction 7.2 Experimental 7.2.1 Geomechanical model 7.2.2 Loading path 7.3 Infrared detection 7.3.1 Infrared thermography and imaging procedures 7.3.2 Temperature calibration 7.3.3 Image processing 7.4 Fourier analysis 7.4.1 Stress wave propagation 7.4.2 Fourier transform 7.4.3 Periodicity in time domain 7.4.4 Periodicity in spatial domain 7.4.5 Physical meaning of the spatial frequency 7.4.6 Method for spectral analysis 7.5 Loading path and overall rock response 7.5.1 Energy release index 7.5.2 Loading rate 7.5.3 Characterization of the loading rate effect 7.6 Results and discussions 7.6.1 Terms and approach 7.6.2 Spectra characterization of loading state A 7.6.3 Characterization of loading cases with slow loading rate 7.6.4 Characterization of loading cases with fast loading rate 7.6.5 Discussions 7.6.6 Summary References …… Chapter 8 Overloaded tunnel in horizontal strata Appendix： The colered thermal images in chapter 4—8
