本书以现场调研、理论分析、相似材料模拟、数值模拟为手段，研究煤层倾角及顶板完整性对沿空留巷适应性的影响，建立了沿空留巷适应性分级系统，介绍了特定地质条件下留巷围岩断裂破坏机理，建立了顶板控制力学模型，*后系统分析了回采巷道围岩破坏特征及控制机理。本书可供从事矿山及地下工程的科研和工程技术人员阅读，也可供高等院校采矿专业的师生参考。

1Introduction1 1.1Classification of Mining Roadways1 1.2Application of GER5 Relief5 1.3Failure Modes of Roadways7 References8 2Overview of Engineering Geology11 2.1Overview11 2.2CoalBearing Strata11 2.3Distribution of Geological Conditions15 2.4Chapter Summary20 References20 3Adaptation Assessment of GobSide Entry Retaining22 3.1Introduction22 3.2Determination of Impact Factors23 3.3Field Application Statistics26 3.4Indicator Weighting30 3.**daptive Grades and Their Support Methods33 3.6Adaptability Evaluation Process37 3.7Chapter Summary41 References41 4Advancing Cutting Roof for Retaining Gateway With Near Horizontal and Close Coal Seam Groups44 4.1Introduction44 4.2Mechanism of the Cutting Roof for a Retaining Gateway45 4.3Equivalent Material Simulation Experiment46 4.4Result of the Experiment50 4.5Discussion59 4.6Chapter Summary60 References61 5Natural Filling and Systematic Roof Control Technology for Retaining Gateway in Steep Coal Seams64 5.1Introduction64 5.2Investigation of Steep Coal Seams65 5.3Analysis of the Advantage of the Use of GER in Steep Coal Seams66 5.4The Key Technology for GER71 5.5Gateway Driving and Its Support Technology77 5.6Chapter Summary81 References81 6Soft Roof Failure Mechanism and Supporting Method for Retaining Gateway84 6.1Introduction84 6.2Description of Field Observation85 6.3Stress Evolution Law in Roof88 6.4Force States of Roof Rock Mass90 6.5Mechanism for Failure of Roof Rock Mass91 Roadway95 6.6Roof Support Countermeasures96 6.7Discussion102 6.8Chapter Summary103 References104 7The Failure Characteristics and the Supporting Technology for PreRetaining Gateway106 7.1Introduction106 7.2Understanding of Surrounding Rock Failure and Its Support107 7.3Investigation of Test Field111 7.4Test of Gateways Broken Width113 7.5CrossSection Diagram of Excavation Broken Zone (EBZ)118 7.6Broken Width in Gateways with Different Excavation Method123 7.7Experimental Studies on the Improved Material Parameters of Bolts125 7.8Support Effect Analyses of Bolt and Surround Rock131 7.9Supporting Technology137 7.10Chapter Summary138 References140 AttachmentEvaluation Results of Adaptability of Gobside Entry Retaining144