Standard No.:	GB 50218-1994
English Name:	Standard for engineering classification of rock masses
Chinese Name:	工程岩体分级标准
Chinese Classification:	P13    Engineering location, hydrogeological survey and geotechnical engineering
Professional Classification:	GB    National Standard
Source Content Issued by:	State Technical Supervision Bureau
Issued on:	1994-11-05
Implemented on:	1995-7-1
Status:	superseded
Superseded by:	GB/T 50218-2014 Standard for engineering classification of rock mass
Superseded on:	2015-5-1
Target Language:	English
File Format:	PDF
Word Count:	5000 words
Translation Price(USD):	120.0
Delivery:	via email in 1 business day

1.0.1 This Standard is formulated with a view to establish an unified method for evaluating the engineering classification of stability of rock masses; provide necessary basis for investigation, design, construction and authorized personnel quota regarding rock engineering construction. 1.0.2 This Standard is applicable to engineering classification of various rock masses. 1.0.3 Engineering classification of rock masses shall adopt a combination of qualitative and quantitative methods, and be carried out in two steps; first to determine the rock mass basic quality and then, rock mass the class of rock mass by combined with the characteristics of specific works. 1.0.4 The geologic survey and rock test required for the engineering classification of rock masses shall not only comply with this Standard, but shall also comply with the provisions specified in current national standards.

1. General Provisions 2. Terminologies and Symbols 2.1 Terminologies 2.2 Symbols 3. Gradation Factor of Rock Mass Basic Quality 3.1 Gradation Factor and Its Determination Method 3.2 Qualitative Classification of Rock Hardness Degree 3.3 Qualitative Classification of Rock mass Intactness 3.4 Determination and Classification of Quantitative Index 4. Classification of Rock Mass Basic Quality 4.1 Determination of Basic Quality Classes 4.2 Qualitative Attribute and Index of Basic Quality 5. Engineering Classification of Rock Masses 5.1 General Rules 5.2 Engineering Classification of Rock Masses Appendix A Test Specifications of Kv and Jv Appendix B Evaluation on Initial Stress Field of Rock Mass Appendix C Physical and Mechanical Parameters of Rock Mass and Structural Plane Appendix D Correction of Rock Mass Basic Quality Index Appendix E Stand-up Time of Rock Mass for Underground Excavation Appendix F Explanation of Wording in this Standard Additional Explanation