An analysis of current intersection support and falls in United States coal mines and recommendations to improve safety

i ACKNOWLEDGMENTS iii LIST OF TABLES vi LIST OF FIGURES vii CHAPTER CHAPTER 1 – INTRODUCTION 1 1.1 Statement of Objective 1 1.2 Significance of the Problem 1 1.3 Information Available Through Regulatory Reports 7 CHAPTER 2 – LITERATURE REVIEW 9 2.1 Coal Mine Layouts and Intersections 9 2.2 Typical Geology Above Coal Seams 11 2.3 Stress Fields Around Coal Seams 11 2.4 Devices Used to Support Coal Mine Roof 12 2.5 Mathematical Models of Roof Stresses and Failures 18 2.6 Previous Studies of Roof Stability 24 CHAPTER 3 – RESEARCH OBJECTIVES AND PROCEDURES 32 3.1 Statement of the Objective 32 3.2 Work Steps to Achieve the Objective 32 CHAPTER 4 – STUDY RESULTS AND DISCUSSION 40 4.1 – Intersection Support Survey 40