Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
According to the requirements of Document Jian Biao [2006] No.77—“Notice on Printing and Distributing the Development and Revision Plan of Engineering Construction Standards and Codes in 2006 (Batch 1)” issued by the former Ministry of Construction (MOC), this code was revised from GB 50011-2001 “Code for Seismic Design of Buildings” by China Academy of Building Research (CABR) together with other design, survey, research and education institutions concerned.
During the process of revision, the editorial team summarized the experiences in building seismic damages during Wenchuan Earthquake in 2008; adjusted the seismic precautionary intensities of the relevant disaster areas; added some compulsory provisions on the sites in mountainous areas, the arrangements of the infilled wall in frame structure, the requirements for staircase of masonry structure and the construction requirements of seismic structure; and raised the requirements for the details of the precast floor slab and for the reinforced elongation. Hereafter, the editorial team carried out studies on specific topics and some tests concerned, investigated and summarized the experiences and lessons from the strong earthquakes occurred in recent years home and abroad (including Wenchuan Earthquake), adopted the new research achievements of earthquake engineering, took the economic condition and construction practices in China into account, widely collected the comments from the relevant design, survey, research and education institutions as well as seismic administration authorities nationwide. Through a multi-round discussion, revision, substantiation, and with pilot designs as well, the final version has been completed and reviewed by an expert panel. This newly-revised version comprises 14 Chapters and 12 Appendixes. Besides remaining those provisions partially revised in 2008, the main revisions at this edition are:
1. supplementing the provisions on the seismic measures for areas with the seismic precaution Intensity 7 (0.15g) and Intensity 8 (0.30g),
2. adjusting the Design Earthquake Groups of Main Cities in China in accordance with GB18306-2001 “Seismic Ground Motion Parameter Zonation Map of China”,
3. improving the soil liquefaction discriminating equation;
4. adjusting the damping modification parameter of design response spectrum,
5. modifying the damping ratio and the seismic adjusting factor for load-bearing capacity of steel structure,
6. modifying the calculation methods of the horizontal seismic-reduced factor of seismically isolated structure,
7. supplementing the calculation method for horizontal and vertical earthquake action of large-span buildings;
8. raising the seismic design requirements for concrete frame structure buildings and for masonry buildings with RC frames on ground floors.
9. proposing the classification method for the seismic grades of steel structure buildings, and adjusting the provisions on seismic measures, correspondingly;
10. improving the seismic measures for multi-storey masonry buildings, concrete wall buildings and reinforced masonry buildings;
11. expending the application scope of seismically isolated and energy-dissipated buildings;
12. adding the principles on performance-based seismic design of for buildings as well as the seismic design provisions for large-span buildings, subterranean buildings, frame-bent structure factories, buildings with composite steel brace and concrete frame structures, and buildings with composite steel frame and concrete core tube structures.
13. canceling the contents related to multi-storey masonry buildings with inner frames.
The provisions printed in bold type are compulsory ones and must be enforced strictly.
The Ministry of Housing and Urban-Rural Development of the People’s Republic of China is in charge of the administration of this code and the explanation of the compulsory provisions hereof. China Academy of Building Research (CABR) is responsible for the explanation of specific technical contents. All relevant organizations are kindly requested to sum up and accumulate your experiences in actual practices during the process of implementing this code. The relevant opinions and advice, whenever necessary, can be posted or passed on to the Management Group of the National Standard “Code for Seismic Design of Buildings” of the China Academy of Building Research (Address: No. 30, Beisanhuan East Road, Beijing City, 100013, China; E-mail: GB50011-cabr@163.com).
Chief Development Organization: China Academy of Building Research (CABR).
Participating Development Organizations: Institute of Engineering Mechanics (IEM) of China Earthquake Administration, China Architecture Design & Research Group, China Institute of Building Standard Design & Research, Beijing Institute of Architectural Design, China Electronics Engineering Design Institute, China Southwest Architectural Design and Research Institute, China Northwest Architectural Design and Research Institute, China Northeast Architecture Design and Research Institute, East China Architectural Design and Research Institute, Central-South Architectural Design Institute, the Architectural Design and Research Institute of Guangdong Province, Shanghai Institute of Architecture Design and Research, Institute of Building Design and Research of Xinjiang Uygur Autonomous Region, Yunnan Province Design Institute, Sichuan Architectural Design Institute, Shenzhen General Institute of Architectural Design and Research, Beijing Geotechnical Institute, Shanghai Tunnel Engineering and Rail Transit Design and Research Institute, China Construction (Shenzhen) Design international, Architecture Design General Institute of China Metallurgical Group Corporation, China National Machinery Industry Corporation, China IPPR International Engineering Corporation, Tsinghua University, Tongji University, Harbin Institute of Technology, Zhejiang University, Chongqing University, Yunnan University, Guangzhou University, Dalian University of Technology and Beijing University of Technology
Chief Drafters: Huang Shimin, Wang Yayong
(The following is according to the Chinese phonetic alphabetically)
Ding Jiemin, Fang Taisheng, Deng Hua, Ye Liaoyuan, Feng Yuan, Lu Xilin, Liu Qiongxiang, Li Liang, Li Hui, Li Lei, Li Xiaojun, Li Yaming, Li Yingmin, Li Guoqiang, Yang Linde, Su Jingyu, Xiao Wei, Wu Mingshun, Xin Hongbo, Zhang Ruilong, Chen Jiong, Chen Fusheng, Ou Jinping, Yu Yinquan, Yi Fangmin, Luo Kaihai, Zhou Zhenghua, Zhou Bingzhang, Zhou Fulin, Zhou Xiyuan, Ke Changhua, Lou Yu, Jiang Wenwei, Yuan Jinxi, Qian Jihong, Qian Jiaru, Xu Jian, Xu Yongji, Tang Caoming, Rong Baisheng, Cao Wenhong, Fu Shengcong, Zhang Yiping, Ge Xueli, Dong Jincheng, Cheng Caiyuan, Fu Xueyi, Zeng Demin, Dou Nanhua, Cai Yiyan, Xue Yantao, Xue Huili and Dai Guoying
Chief Examiners: Xu Peifu, Wu Xuemin, Liu Zhigang
(The following is according to the Chinese phonetic alphabetically)
Liu Shutun, Li Li, Li Xuelan, Chen Guoyi, Hou Zhongliang, Mo Yong, Gu Baohe, Gao Mengtan, Huang Xiaokun and Cheng Maokun
Contents
1 General 12
2 Terms and Symbols 13
2.1 Terms 13
2.2 Symbols 14
3 Basic Requirements of Seismic Design 16
3.1 Category and Criterion for Seismic Precaution of Buildings 16
3.2 Earthquake Ground Motion 16
3.3 Site and Soil 16
3.4 Regularity of Building Configuration and Structural Assembly 17
3.5 Structural System 20
3.6 Structural Analysis 21
3.7 Nonstructural Components 22
3.8 Isolation and Energy-Dissipation 23
3.9 Materials and Construction 23
3.10 Seismic Performance-Based Design of Buildings 24
3.11 Seismic Response Observation System of Buildings 26
4 Site, Soil and Foundation 27
4.1 Site 27
4.2 Natural Soil and Foundation 30
4.3 Liquefied Soil and Soft Soil 31
4.4 Pile Foundation 36
5 Earthquake Action and Seismic Checking for Structures 37
5.1 General 38
5.2 Calculation of Horizontal Earthquake Action 42
5.3 Calculation of Vertical Earthquake Action 47
5.4 Seismic Checking for the Sections of Structural Member 48
5.5 Seismic Checking for the Storey Drift 50
6 Multi-storey and Tall Reinforced Concrete Buildings 54
6.1 General 54
6.2 Essentials in Calculation 60
6.3 Details of Seismic Design for Frame Structures 65
6.4 Details of Seismic Design for Seismic Wall Structures 71
6.5 Details of Seismic Design for Frame-seismic-Wall Structures 74
6.6 Requirements for Seismic Design of Slab-column-seismic-Wall Structures 75
6.7 Requirements for Seismic Design of Tube Structures 76
7 Multi-storey Masonry Buildings and Multi-storey Masonry Buildings with RC Frames on Ground Floors 79
7.1 General 79
7.2 Essentials in Calculation 84
7.3 Details of Seismic Design of Multi-storey Brick Buildings 89
7.4 Details of Seismic Design of Multi-storey Concrete Block Buildings 94
7.5 Details of Seismic Design of Multi-storey Masonry Buildings with RC Frames and Seismic-Walls on Ground Floors 97
8 Multi-Storey and Tall Steel Buildings 101
8.1 General 101
8.2 Essentials in Calculation 103
8.3 Details for Steel Frame Structures 109
8.4 Details for Steel Frame-concentrically-braced Structures 112
8.5 Details for Steel Frame-eccentrically-braced Structures 113
9 Single-storey Factory Buildings 116
9.1 Single-storey Factory Buildings with Reinforced Concrete Columns 116
9.2 Single-storey Steel Factory Buildings 126
9.3 Single-storey Factory Buildings with Brick Columns 132
10 Large-span Buildings 136
10.1 Single-storey Spacious Buildings 136
10.2 Large-span Roof Buildings 138
11 Earth, Wood and Stone Houses 143
11.1 General 143
11.2 Unfired Earth Houses 144
11.3 Wood Houses 145
11.4 Stone Houses 147
12 Seismically Isolated and Energy-Dissipated Buildings 149
12.1 General 149
12.2 Essentials in Design of Seismically Isolated Buildings 150
12.3 Essentials in Design of Seismic-energy-dissipated Buildings 155
13 Nonstructural Components 160
13.1 General 160
13.2 Basic Requirements for Calculation 160
13.3 Basic Seismic-Measures for Architectural Members 162
14 Subterranean Buildings 167
14.1 General 167
14.2 Essentials in Calculation 167
14.3 Seismic Details and Anti-liquefaction Measures 169
Appendix A The Seismic Precautionary Intensity, Design Basic Acceleration of Ground Motion and Design Earthquake Groups of Main Cities and Towns in China 171
Appendix B Requirements for Seismic Design of High Strength Concrete Structures 206
Appendix C Requirements for Seismic Design of Prestressed Concrete Structures 208
Appendix D Section Seismic Check for the Beam-column Joint Core Zone of Frames 210
Appendix E Requirements for Seismic Design of the Transfer Storey Structures 214
Appendix F Requirements for Seismic Design of Reinforced Concrete Small-sized Hollow Block Seismic -Wall Buildings 216
Appendix G Requirements for Seismic Design of Buildings with Steel Brace-Concrete Frame Structures and Steel Frame-Reinforced Concrete Core Tube Structures 224
Appendix H Requirements for Seismic Design of Multi-storey Factory Buildings 227
Appendix J Seismic Effect Adjustment for Transversal Planar-Bent of Single-Storey Factory 234
Appendix K Longitudinal Seismic Check for Single-Storey Factory 237
Appendix L Simplified Calculation for Seismically Isolated Design and Seismically Isolated Measures of Masonry Structures 243
Appendix M Reference Procedures of Performance-based Seismic Design 248
Explanation of Wording in This Code 255
List of Quoted Standards 256
1 General
1.0.1 This code is formulated with a view to implementing the relevant laws and regulations on construction engineering and protecting against and mitigating earthquake disasters, carrying out the policy of “prevention first”, as well as alleviating the seismic damage of buildings, avoiding casualties and reducing economic loss through seismic precautionary of buildings.
The basic seismic precautionary objectives of buildings which designed and constructed in accordance with this code, are as follows:
1) under the frequent earthquake ground motion with an intensity being less than the local Seismic Precautionary Intensity, the buildings with major structure undamaged or requiring no repair may continue to serve;
2) under the earthquake ground motion with an intensity being equivalent to the local Seismic Precautionary Intensity, the buildings with possible damage may continue to serve with common repair; or
3) under the rare earthquake ground motion with an intensity being larger than the local Seismic Precautionary Intensity, the buildings shall not collapse or shall be free from such severe damage that may endanger human lives.
If the buildings with special requirements in functions or other aspects are carried out with the seismic performance-based design, more concrete and higher seismic precautionary objectives shall be established.
1.0.2 All the buildings situated on zones of Seismic Precautionary Intensity 6 or above must be carried out with seismic design.
1.0.3 This code is applicable to the seismic design and the isolation and energy-dissipation design of the buildings suited on zones of Seismic Precautionary Intensity 6, 7, 8 and 9. And the seismic performance-based design of buildings may be implemented in accordance with the basic methods specified in this code.
As for the buildings suited on zones where the Seismic Precautionary Intensity is above Intensity 9 and the industrial buildings for special purpose, their seismic design shall be carried out according to the relevant special provisions.
Note: For the purposes of this code, “Seismic Precautionary Intensity 6, 7, 8 and 9” hereinafter is referred to “Intensity 6, 7, 8 and 9”.
1.0.4 The Seismic Precautionary Intensity must be determined in accordance with the documents (drawings) examined, approved and issued by the authorities appointed by the State.
1.0.5 Generally, the seismic precautionary intensity of buildings shall be adopted with the basic seismic intensity (the intensity values corresponding to the design basic acceleration of ground motion value in this code) determined according to the “Seismic Ground Motion Parameter Zonation Map of China”.
1.0.6 In addition to the requirements of this code, the seismic design of buildings also shall comply with the requirements specified in the relevant current standards of the State.
2 Terms and Symbols
2.1 Terms
2.1.1 Seismic precautionary intensity
The seismic intensity approved by the authority appointed by the State, which is used as the basis for the seismic precaution of buildings in a certain region. Generally, it is taken as the seismic Intensity with a 10% probability of exceedance in 50 years.
2.1.2 Seismic precautionary criterion
The rule for judging the seismic precautionary requirements, which is dependent on the Seismic Precautionary Intensity or the design parameters of ground motion and the precautionary category of buildings.
2.1.3 Seismic ground motion parameter zonation map
The map in which the whole county is divided into regions with different seismic precautionary requirements according to the ground motion parameter (that is the degree of earthquake ground motion intensity indicated by acceleration).
2.1.4 Earthquake action
The dynamic response of structure caused by earthquake ground motion, including horizontal and vertical earthquake action.
2.1.5 Design parameters of earthquake ground motion
The parameters of earthquake ground motion used in seismic design, including the acceleration (velocity or displacement) time history of the earthquake ground motion , the acceleration response spectrum and the peak value of ground acceleration
2.1.6 Design basic acceleration of earthquake ground motion
The design value of seismic acceleration with a 10% probability of exceedance in the 50-years design reference period.
2.1.7 Design characteristic period of earthquake ground motion
The period value corresponding to the starting point of the descending section of the seismic influence coefficient curve used for seismic design, that is dependent on the earthquake magnitude, epicentral distance, site class and etc. For convenience, it is named as “characteristic period” for short.
2.1.8 Site
Locations of the project colonies, being with similar characteristics of response spectra. The scope of site is equivalent to plant area, residential area and natural village or the plane area no less than 1.0km2.
2.1.9 Seismic concept design of buildings
The process of making the general arrangement for the buildings and structures and of determining details, based on the fundamental design principles and concepts obtained from the past experiences in earthquake disasters and projects.
2.1.10 Seismic measures
The seismic design contents except earthquake action calculation and member resistance calculation, including the details of seismic design.
2.1.11 Details of seismic design
All the detailed requirements that must be taken for the structural and nonstructural components according to seismic concept design principles and require no calculation generally.
2.2 Symbols
2.2.1 Actions and effects
FEk, FEvk—— Standard values of total horizontal and vertical earthquake actions of structure respectively;
GE, Geq—— Representative value of gravity load of structure (or component) and the total equivalent representative value of gravity load of a structure ,respectively;
wK—— Standard value of wind load;
SE—— Seismic effect (bending moment, axial force, shear, stress and deformation);
S—— Fundamental combination values of the effects of earthquake action and other loads;
Sk—— Effect of the standard value of action or load;
M—— Bending moment;
N—— Axial force;
V—— Shear;
p—— Pressure on bottom of foundation;
u—— Lateral displacement;
θ—— Storey drift
2.2.2 Material properties and resistance
K—— Stiffness of structure (member);
R—— Resistant capacity of structural component;
f, fk, fE—— Design value, standard value and seismic design value of various material strength (including the bearing capacity of soil) , respectively;
[θ]—— Allowable storey drift.
2.2.3 Geometric parameters
A—— Cross-sectional area of member;
As—— Cross-sectional area of reinforcement;
B—— Total width of structure;
H—— Total height of structure, or the column height;
L—— Total length of structure (unit);
α—— Distance;
as, a's—— Minimal distance from the force point of the longitudinal tensile and compressive reinforcements to the margin of section, respectively;
b—— Sectional width of member;
d—— Depth or thickness of soil layer, or the diameter of reinforcement;
h—— Depth of cross-section of member;
l—— Length or span of member;
t—— Thickness of wall or floor slab.
2.2.4 Coefficients of calculation
α—— Horizontal seismic influence coefficient;
αmax—— Maximum value of horizontal seismic influence coefficient;
αvmax—— Maximum value of vertical seismic influence coefficient;
γG, γE, γW—— Partial factor of action;
γRE—— seismic adjusting factor for load-bearing capacity;
ζ—— Calculation coefficient;
η—— Enhancement or adjustment coefficient of earthquake action effect (internal force or deformation);
λ—— Slenderness ratio of member, or the proportionality coefficient;
ξy—— Yield strength coefficient of structure (member);
ρ—— Reinforcement ratio or ratio;
ø—— Stability coefficient of compressive member;
—— Combination value coefficient or the influence coefficient.
2.2.5 Others
T—— Natural vibration period of structure;
N—— Penetration resistance (in blow number);
IlE—— Liquefaction index of soil under earthquake;
Xji—— The coordinate of modal displacement (relative displacement of the ith mass point of the jth mode in x direction);
Yji—— The coordinate of modal displacement (relative displacement of the ith mass point of the jth mode in y direction);
n—— Total number, such as number of storeys, masses, reinforcements and spans, etc.;
υse—— Equivalent shear wave velocity of soil layer;
Φji—— The coordinate of modal rotation (relative rotation of the ith mass point of the jth mode around the z axial direction).
3 Basic Requirements of Seismic Design
3.1 Category and Criterion for Seismic Precaution of Buildings
3.1.1 The seismic precautionary category and the seismic precautionary criterion of buildings shall be determined in accordance with the current national standard GB 50223 “Standard for Classification of Seismic Protection of Building Constructions”.
3.1.2 Unless otherwise specified in this code, Categories B, C and D buildings with seismic precautionary intensity 6 may not be carried out the calculation of earthquake action.
3.2 Earthquake Ground Motion
3.2.1 The earthquake ground motion of the zones in which buildings are suited shall be represented by design basic acceleration and characteristic period of earthquake ground motion corresponding to the seismic precautionary intensity.
3.2.2 The corresponding relationship between the seismic precautionary intensity and the design basic acceleration of ground motion shall be in accordance with those specified in Table 3.2.2. Unless otherwise stated in this code, the buildings in such zones where the design basic acceleration of ground motion is 0.15g and 0.30g shall be carried out with seismic design respectively according to the requirements of seismic precautionary intensity 7 and 8.
Table 3.2.2 Corresponding Relationship Between Seismic Precautionary Intensity and Design Basic Acceleration of Ground Motion
Seismic precautionary intensity 6 7 8 9
Design basic acceleration value of ground motion 0.05g 0.10 (0.15)g 0.20 (0.30)g 0.40g
Note: g is the gravity acceleration.
3.2.3 The characteristic period of earthquake ground motion shall be determined according to the design earthquake groups and the site class of the building site. The design earthquakes in this code are totally divided into three groups, and their characteristic periods shall be adopted according to the relevant provisions in Chapter 5 of this code.
3.2.4 The seismic precautionary intensity, design basic acceleration of ground motion and design earthquake groups of the central areas in the main cities in China may be adopted according to Appendix A of this code.
Contents
Chapter 1 General
Chapter 2 Terms and Symbols
2.1 Terms
2.2 Symbols
Chapter 3 Basic Requirements of Seismic Design
3.1 Category and Criterion for Seismic Precaution of Buildings
3.2 Earthquake Effect
3.3 Site and Base
3.4 Regularity of Building Configuration and Structural Assembly
3.5 Structural System
3.6 Structural Analysis
3.7 Nonstructural Components
3.8 Isolation and Energy-Dissipation
3.9 Materials and Construction
3.10 Performance-Based Design of Buildings
3.11 Seismic Response Observation System of Buildings
Chapter 4 Site, Base and Foundation
4.1 Site
4.2 Natural Base and Foundation
4.3 Liquefied Soil and Soft Soil Bases
4.4 Pile Foundations
Chapter 5 Earthquake Action and Seismic Checking for Structures
5.1 General
5.2 Calculation of Horizontal Earthquake Action
5.3 Calculation of Vertical Earthquake Action
5.4 Section Seismic Check
5.5 Seismic Deformation Check
Chapter 6 Multi-storey and Tall Reinforced Concrete Buildings
6.1 General
6.2 Essentials in Calculation
6.3 Details of Seismic Design for Frame Structures
6.4 Details of Seismic Design for Seismic Wall Structures
6.5 Details of Seismic Design for Frame-seismic Wall Structures
6.6 Requirements for Seismic Design of Slab-column-seismic Wall Structures
6.7 Requirements for Seismic Design of Tube Structures
Chapter 7 Multi-storey Masonry Buildings and Multi-storey Masonry Buildings with R.C. Frames on Ground Floors
7.1 General
7.2 Essentials in Calculation
7.3 Details of Seismic Design of Multi-storey Brick Buildings
7.4 Details of Seismic Design of Multi-storey Concrete Block Buildings
7.5 Details of Seismic Design of Multi-storey Masonry Buildings with R.C. Frames on Ground Floors
Chapter 8 Multi-Storey and Tall Steel Buildings
8.1 General
8.2 Essentials in Calculation
8.3 Details for Steel Frame Structures
8.4 Details of Seismic Design of Steel Frame-concentrically-supported Structures
8.5 Details for Seismic Design of Steel Frame-eccentrically-supported Structures
Chapter 9 Single-storey Factory Buildings
9.1 Single-storey Factory Buildings with R.C. Columns
9.2 Single-storey Steel Factory Buildings
9.3 Single-storey Factory Buildings with Brick Columns
Chapter 10 Large-span Buildings
10.1 Single-storey Spacious Buildings
10.2 Large-span Roof Buildings
Chapter 11 Earth, Wood and Stone Houses
11.1 General
11.2 Unfired Earth Houses
11.3 Wood Houses
11.4 Stone Houses
Chapter 12 Seismically Isolated and Energy-Dissipated Buildings
12.1 General
12.2 Essentials in Design of Seismically Isolated Buildings
12.3 Essentials in Design of Energy-dissipated Buildings
Chapter 13 Nonstructural Components
13.1 General
13.2 Essentials in Calculation
13.3 Essential Measures for Architectural Members
13.4 Essential Measures for Supports of Mechanical and Electrical Components
Chapter 14 Subterranean Buildings
14.1 General
14.2 Essentials in Calculation
14.3 Details and Anti-Liquefaction Measures
Appendix A The Seismic Precautionary Intensity, Design Basic Acceleration of Ground Motion and Design Earthquake Groups of Main Cities in China
Appendix B Requirements for Seismic Design of High Strength Concrete Structures
Appendix C Requirements for Seismic Design of Prestressed Concrete Structures
Appendix D Section Seismic Check for the Beam-column Joint Core Zone of Frames
Appendix E Requirements for Seismic Design of the Transfer Storey Structures
Appendix F Requirements for Seismic Design of Small Armored Concrete Hollow Block Buildings with Seismic Wall
Appendix G Requirements for Seismic Design of Buildings with Steel Support-Concrete Frame Structures and Steel Frame-Armored Concrete Core Tube Structures
Appendix H Requirements for Seismic Design of Multi-storey Factory Buildings
Appendix J Earthquake Action Effect Adjustment for Transverse Plane Bent Frame of Single-storey Factory Buildings
Appendix K Seismic Check for Single-storey Factory Buildings in Longitudinal Direction
Appendix L Simplified Calculation of Seismic Isolation Design and Seismic Isolation Measures for Masonry Structures
Appendix M Reference Methods for Achieving Performance-Based Seismic Design
Explanation of Wording in This Code
List of Quoted Standards
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
According to the requirements of Document Jian Biao [2006] No.77—“Notice on Printing and Distributing the Development and Revision Plan of Engineering Construction Standards and Codes in 2006 (Batch 1)” issued by the former Ministry of Construction (MOC), this code was revised from GB 50011-2001 “Code for Seismic Design of Buildings” by China Academy of Building Research (CABR) together with other design, survey, research and education institutions concerned.
During the process of revision, the editorial team summarized the experiences in building seismic damages during Wenchuan Earthquake in 2008; adjusted the seismic precautionary intensities of the relevant disaster areas; added some compulsory provisions on the sites in mountainous areas, the arrangements of the infilled wall in frame structure, the requirements for staircase of masonry structure and the construction requirements of seismic structure; and raised the requirements for the details of the precast floor slab and for the reinforced elongation. Hereafter, the editorial team carried out studies on specific topics and some tests concerned, investigated and summarized the experiences and lessons from the strong earthquakes occurred in recent years home and abroad (including Wenchuan Earthquake), adopted the new research achievements of earthquake engineering, took the economic condition and construction practices in China into account, widely collected the comments from the relevant design, survey, research and education institutions as well as seismic administration authorities nationwide. Through a multi-round discussion, revision, substantiation, and with pilot designs as well, the final version has been completed and reviewed by an expert panel. This newly-revised version comprises 14 Chapters and 12 Appendixes. Besides remaining those provisions partially revised in 2008, the main revisions at this edition are:
1. supplementing the provisions on the seismic measures for areas with the seismic precaution Intensity 7 (0.15g) and Intensity 8 (0.30g),
2. adjusting the Design Earthquake Groups of Main Cities in China in accordance with GB18306-2001 “Seismic Ground Motion Parameter Zonation Map of China”,
3. improving the soil liquefaction discriminating equation;
4. adjusting the damping modification parameter of design response spectrum,
5. modifying the damping ratio and the seismic adjusting factor for load-bearing capacity of steel structure,
6. modifying the calculation methods of the horizontal seismic-reduced factor of seismically isolated structure,
7. supplementing the calculation method for horizontal and vertical earthquake action of large-span buildings;
8. raising the seismic design requirements for concrete frame structure buildings and for masonry buildings with RC frames on ground floors.
9. proposing the classification method for the seismic grades of steel structure buildings, and adjusting the provisions on seismic measures, correspondingly;
10. improving the seismic measures for multi-storey masonry buildings, concrete wall buildings and reinforced masonry buildings;
11. expending the application scope of seismically isolated and energy-dissipated buildings;
12. adding the principles on performance-based seismic design of for buildings as well as the seismic design provisions for large-span buildings, subterranean buildings, frame-bent structure factories, buildings with composite steel brace and concrete frame structures, and buildings with composite steel frame and concrete core tube structures.
13. canceling the contents related to multi-storey masonry buildings with inner frames.
The provisions printed in bold type are compulsory ones and must be enforced strictly.
The Ministry of Housing and Urban-Rural Development of the People’s Republic of China is in charge of the administration of this code and the explanation of the compulsory provisions hereof. China Academy of Building Research (CABR) is responsible for the explanation of specific technical contents. All relevant organizations are kindly requested to sum up and accumulate your experiences in actual practices during the process of implementing this code. The relevant opinions and advice, whenever necessary, can be posted or passed on to the Management Group of the National Standard “Code for Seismic Design of Buildings” of the China Academy of Building Research (Address: No. 30, Beisanhuan East Road, Beijing City, 100013, China; E-mail: GB50011-cabr@163.com).
Chief Development Organization: China Academy of Building Research (CABR).
Participating Development Organizations: Institute of Engineering Mechanics (IEM) of China Earthquake Administration, China Architecture Design & Research Group, China Institute of Building Standard Design & Research, Beijing Institute of Architectural Design, China Electronics Engineering Design Institute, China Southwest Architectural Design and Research Institute, China Northwest Architectural Design and Research Institute, China Northeast Architecture Design and Research Institute, East China Architectural Design and Research Institute, Central-South Architectural Design Institute, the Architectural Design and Research Institute of Guangdong Province, Shanghai Institute of Architecture Design and Research, Institute of Building Design and Research of Xinjiang Uygur Autonomous Region, Yunnan Province Design Institute, Sichuan Architectural Design Institute, Shenzhen General Institute of Architectural Design and Research, Beijing Geotechnical Institute, Shanghai Tunnel Engineering and Rail Transit Design and Research Institute, China Construction (Shenzhen) Design international, Architecture Design General Institute of China Metallurgical Group Corporation, China National Machinery Industry Corporation, China IPPR International Engineering Corporation, Tsinghua University, Tongji University, Harbin Institute of Technology, Zhejiang University, Chongqing University, Yunnan University, Guangzhou University, Dalian University of Technology and Beijing University of Technology
Chief Drafters: Huang Shimin, Wang Yayong
(The following is according to the Chinese phonetic alphabetically)
Ding Jiemin, Fang Taisheng, Deng Hua, Ye Liaoyuan, Feng Yuan, Lu Xilin, Liu Qiongxiang, Li Liang, Li Hui, Li Lei, Li Xiaojun, Li Yaming, Li Yingmin, Li Guoqiang, Yang Linde, Su Jingyu, Xiao Wei, Wu Mingshun, Xin Hongbo, Zhang Ruilong, Chen Jiong, Chen Fusheng, Ou Jinping, Yu Yinquan, Yi Fangmin, Luo Kaihai, Zhou Zhenghua, Zhou Bingzhang, Zhou Fulin, Zhou Xiyuan, Ke Changhua, Lou Yu, Jiang Wenwei, Yuan Jinxi, Qian Jihong, Qian Jiaru, Xu Jian, Xu Yongji, Tang Caoming, Rong Baisheng, Cao Wenhong, Fu Shengcong, Zhang Yiping, Ge Xueli, Dong Jincheng, Cheng Caiyuan, Fu Xueyi, Zeng Demin, Dou Nanhua, Cai Yiyan, Xue Yantao, Xue Huili and Dai Guoying
Chief Examiners: Xu Peifu, Wu Xuemin, Liu Zhigang
(The following is according to the Chinese phonetic alphabetically)
Liu Shutun, Li Li, Li Xuelan, Chen Guoyi, Hou Zhongliang, Mo Yong, Gu Baohe, Gao Mengtan, Huang Xiaokun and Cheng Maokun
Contents
1 General 12
2 Terms and Symbols 13
2.1 Terms 13
2.2 Symbols 14
3 Basic Requirements of Seismic Design 16
3.1 Category and Criterion for Seismic Precaution of Buildings 16
3.2 Earthquake Ground Motion 16
3.3 Site and Soil 16
3.4 Regularity of Building Configuration and Structural Assembly 17
3.5 Structural System 20
3.6 Structural Analysis 21
3.7 Nonstructural Components 22
3.8 Isolation and Energy-Dissipation 23
3.9 Materials and Construction 23
3.10 Seismic Performance-Based Design of Buildings 24
3.11 Seismic Response Observation System of Buildings 26
4 Site, Soil and Foundation 27
4.1 Site 27
4.2 Natural Soil and Foundation 30
4.3 Liquefied Soil and Soft Soil 31
4.4 Pile Foundation 36
5 Earthquake Action and Seismic Checking for Structures 37
5.1 General 38
5.2 Calculation of Horizontal Earthquake Action 42
5.3 Calculation of Vertical Earthquake Action 47
5.4 Seismic Checking for the Sections of Structural Member 48
5.5 Seismic Checking for the Storey Drift 50
6 Multi-storey and Tall Reinforced Concrete Buildings 54
6.1 General 54
6.2 Essentials in Calculation 60
6.3 Details of Seismic Design for Frame Structures 65
6.4 Details of Seismic Design for Seismic Wall Structures 71
6.5 Details of Seismic Design for Frame-seismic-Wall Structures 74
6.6 Requirements for Seismic Design of Slab-column-seismic-Wall Structures 75
6.7 Requirements for Seismic Design of Tube Structures 76
7 Multi-storey Masonry Buildings and Multi-storey Masonry Buildings with RC Frames on Ground Floors 79
7.1 General 79
7.2 Essentials in Calculation 84
7.3 Details of Seismic Design of Multi-storey Brick Buildings 89
7.4 Details of Seismic Design of Multi-storey Concrete Block Buildings 94
7.5 Details of Seismic Design of Multi-storey Masonry Buildings with RC Frames and Seismic-Walls on Ground Floors 97
8 Multi-Storey and Tall Steel Buildings 101
8.1 General 101
8.2 Essentials in Calculation 103
8.3 Details for Steel Frame Structures 109
8.4 Details for Steel Frame-concentrically-braced Structures 112
8.5 Details for Steel Frame-eccentrically-braced Structures 113
9 Single-storey Factory Buildings 116
9.1 Single-storey Factory Buildings with Reinforced Concrete Columns 116
9.2 Single-storey Steel Factory Buildings 126
9.3 Single-storey Factory Buildings with Brick Columns 132
10 Large-span Buildings 136
10.1 Single-storey Spacious Buildings 136
10.2 Large-span Roof Buildings 138
11 Earth, Wood and Stone Houses 143
11.1 General 143
11.2 Unfired Earth Houses 144
11.3 Wood Houses 145
11.4 Stone Houses 147
12 Seismically Isolated and Energy-Dissipated Buildings 149
12.1 General 149
12.2 Essentials in Design of Seismically Isolated Buildings 150
12.3 Essentials in Design of Seismic-energy-dissipated Buildings 155
13 Nonstructural Components 160
13.1 General 160
13.2 Basic Requirements for Calculation 160
13.3 Basic Seismic-Measures for Architectural Members 162
14 Subterranean Buildings 167
14.1 General 167
14.2 Essentials in Calculation 167
14.3 Seismic Details and Anti-liquefaction Measures 169
Appendix A The Seismic Precautionary Intensity, Design Basic Acceleration of Ground Motion and Design Earthquake Groups of Main Cities and Towns in China 171
Appendix B Requirements for Seismic Design of High Strength Concrete Structures 206
Appendix C Requirements for Seismic Design of Prestressed Concrete Structures 208
Appendix D Section Seismic Check for the Beam-column Joint Core Zone of Frames 210
Appendix E Requirements for Seismic Design of the Transfer Storey Structures 214
Appendix F Requirements for Seismic Design of Reinforced Concrete Small-sized Hollow Block Seismic -Wall Buildings 216
Appendix G Requirements for Seismic Design of Buildings with Steel Brace-Concrete Frame Structures and Steel Frame-Reinforced Concrete Core Tube Structures 224
Appendix H Requirements for Seismic Design of Multi-storey Factory Buildings 227
Appendix J Seismic Effect Adjustment for Transversal Planar-Bent of Single-Storey Factory 234
Appendix K Longitudinal Seismic Check for Single-Storey Factory 237
Appendix L Simplified Calculation for Seismically Isolated Design and Seismically Isolated Measures of Masonry Structures 243
Appendix M Reference Procedures of Performance-based Seismic Design 248
Explanation of Wording in This Code 255
List of Quoted Standards 256
1 General
1.0.1 This code is formulated with a view to implementing the relevant laws and regulations on construction engineering and protecting against and mitigating earthquake disasters, carrying out the policy of “prevention first”, as well as alleviating the seismic damage of buildings, avoiding casualties and reducing economic loss through seismic precautionary of buildings.
The basic seismic precautionary objectives of buildings which designed and constructed in accordance with this code, are as follows:
1) under the frequent earthquake ground motion with an intensity being less than the local Seismic Precautionary Intensity, the buildings with major structure undamaged or requiring no repair may continue to serve;
2) under the earthquake ground motion with an intensity being equivalent to the local Seismic Precautionary Intensity, the buildings with possible damage may continue to serve with common repair; or
3) under the rare earthquake ground motion with an intensity being larger than the local Seismic Precautionary Intensity, the buildings shall not collapse or shall be free from such severe damage that may endanger human lives.
If the buildings with special requirements in functions or other aspects are carried out with the seismic performance-based design, more concrete and higher seismic precautionary objectives shall be established.
1.0.2 All the buildings situated on zones of Seismic Precautionary Intensity 6 or above must be carried out with seismic design.
1.0.3 This code is applicable to the seismic design and the isolation and energy-dissipation design of the buildings suited on zones of Seismic Precautionary Intensity 6, 7, 8 and 9. And the seismic performance-based design of buildings may be implemented in accordance with the basic methods specified in this code.
As for the buildings suited on zones where the Seismic Precautionary Intensity is above Intensity 9 and the industrial buildings for special purpose, their seismic design shall be carried out according to the relevant special provisions.
Note: For the purposes of this code, “Seismic Precautionary Intensity 6, 7, 8 and 9” hereinafter is referred to “Intensity 6, 7, 8 and 9”.
1.0.4 The Seismic Precautionary Intensity must be determined in accordance with the documents (drawings) examined, approved and issued by the authorities appointed by the State.
1.0.5 Generally, the seismic precautionary intensity of buildings shall be adopted with the basic seismic intensity (the intensity values corresponding to the design basic acceleration of ground motion value in this code) determined according to the “Seismic Ground Motion Parameter Zonation Map of China”.
1.0.6 In addition to the requirements of this code, the seismic design of buildings also shall comply with the requirements specified in the relevant current standards of the State.
2 Terms and Symbols
2.1 Terms
2.1.1 Seismic precautionary intensity
The seismic intensity approved by the authority appointed by the State, which is used as the basis for the seismic precaution of buildings in a certain region. Generally, it is taken as the seismic Intensity with a 10% probability of exceedance in 50 years.
2.1.2 Seismic precautionary criterion
The rule for judging the seismic precautionary requirements, which is dependent on the Seismic Precautionary Intensity or the design parameters of ground motion and the precautionary category of buildings.
2.1.3 Seismic ground motion parameter zonation map
The map in which the whole county is divided into regions with different seismic precautionary requirements according to the ground motion parameter (that is the degree of earthquake ground motion intensity indicated by acceleration).
2.1.4 Earthquake action
The dynamic response of structure caused by earthquake ground motion, including horizontal and vertical earthquake action.
2.1.5 Design parameters of earthquake ground motion
The parameters of earthquake ground motion used in seismic design, including the acceleration (velocity or displacement) time history of the earthquake ground motion , the acceleration response spectrum and the peak value of ground acceleration
2.1.6 Design basic acceleration of earthquake ground motion
The design value of seismic acceleration with a 10% probability of exceedance in the 50-years design reference period.
2.1.7 Design characteristic period of earthquake ground motion
The period value corresponding to the starting point of the descending section of the seismic influence coefficient curve used for seismic design, that is dependent on the earthquake magnitude, epicentral distance, site class and etc. For convenience, it is named as “characteristic period” for short.
2.1.8 Site
Locations of the project colonies, being with similar characteristics of response spectra. The scope of site is equivalent to plant area, residential area and natural village or the plane area no less than 1.0km2.
2.1.9 Seismic concept design of buildings
The process of making the general arrangement for the buildings and structures and of determining details, based on the fundamental design principles and concepts obtained from the past experiences in earthquake disasters and projects.
2.1.10 Seismic measures
The seismic design contents except earthquake action calculation and member resistance calculation, including the details of seismic design.
2.1.11 Details of seismic design
All the detailed requirements that must be taken for the structural and nonstructural components according to seismic concept design principles and require no calculation generally.
2.2 Symbols
2.2.1 Actions and effects
FEk, FEvk—— Standard values of total horizontal and vertical earthquake actions of structure respectively;
GE, Geq—— Representative value of gravity load of structure (or component) and the total equivalent representative value of gravity load of a structure ,respectively;
wK—— Standard value of wind load;
SE—— Seismic effect (bending moment, axial force, shear, stress and deformation);
S—— Fundamental combination values of the effects of earthquake action and other loads;
Sk—— Effect of the standard value of action or load;
M—— Bending moment;
N—— Axial force;
V—— Shear;
p—— Pressure on bottom of foundation;
u—— Lateral displacement;
θ—— Storey drift
2.2.2 Material properties and resistance
K—— Stiffness of structure (member);
R—— Resistant capacity of structural component;
f, fk, fE—— Design value, standard value and seismic design value of various material strength (including the bearing capacity of soil) , respectively;
[θ]—— Allowable storey drift.
2.2.3 Geometric parameters
A—— Cross-sectional area of member;
As—— Cross-sectional area of reinforcement;
B—— Total width of structure;
H—— Total height of structure, or the column height;
L—— Total length of structure (unit);
α—— Distance;
as, a's—— Minimal distance from the force point of the longitudinal tensile and compressive reinforcements to the margin of section, respectively;
b—— Sectional width of member;
d—— Depth or thickness of soil layer, or the diameter of reinforcement;
h—— Depth of cross-section of member;
l—— Length or span of member;
t—— Thickness of wall or floor slab.
2.2.4 Coefficients of calculation
α—— Horizontal seismic influence coefficient;
αmax—— Maximum value of horizontal seismic influence coefficient;
αvmax—— Maximum value of vertical seismic influence coefficient;
γG, γE, γW—— Partial factor of action;
γRE—— seismic adjusting factor for load-bearing capacity;
ζ—— Calculation coefficient;
η—— Enhancement or adjustment coefficient of earthquake action effect (internal force or deformation);
λ—— Slenderness ratio of member, or the proportionality coefficient;
ξy—— Yield strength coefficient of structure (member);
ρ—— Reinforcement ratio or ratio;
ø—— Stability coefficient of compressive member;
—— Combination value coefficient or the influence coefficient.
2.2.5 Others
T—— Natural vibration period of structure;
N—— Penetration resistance (in blow number);
IlE—— Liquefaction index of soil under earthquake;
Xji—— The coordinate of modal displacement (relative displacement of the ith mass point of the jth mode in x direction);
Yji—— The coordinate of modal displacement (relative displacement of the ith mass point of the jth mode in y direction);
n—— Total number, such as number of storeys, masses, reinforcements and spans, etc.;
υse—— Equivalent shear wave velocity of soil layer;
Φji—— The coordinate of modal rotation (relative rotation of the ith mass point of the jth mode around the z axial direction).
3 Basic Requirements of Seismic Design
3.1 Category and Criterion for Seismic Precaution of Buildings
3.1.1 The seismic precautionary category and the seismic precautionary criterion of buildings shall be determined in accordance with the current national standard GB 50223 “Standard for Classification of Seismic Protection of Building Constructions”.
3.1.2 Unless otherwise specified in this code, Categories B, C and D buildings with seismic precautionary intensity 6 may not be carried out the calculation of earthquake action.
3.2 Earthquake Ground Motion
3.2.1 The earthquake ground motion of the zones in which buildings are suited shall be represented by design basic acceleration and characteristic period of earthquake ground motion corresponding to the seismic precautionary intensity.
3.2.2 The corresponding relationship between the seismic precautionary intensity and the design basic acceleration of ground motion shall be in accordance with those specified in Table 3.2.2. Unless otherwise stated in this code, the buildings in such zones where the design basic acceleration of ground motion is 0.15g and 0.30g shall be carried out with seismic design respectively according to the requirements of seismic precautionary intensity 7 and 8.
Table 3.2.2 Corresponding Relationship Between Seismic Precautionary Intensity and Design Basic Acceleration of Ground Motion
Seismic precautionary intensity 6 7 8 9
Design basic acceleration value of ground motion 0.05g 0.10 (0.15)g 0.20 (0.30)g 0.40g
Note: g is the gravity acceleration.
3.2.3 The characteristic period of earthquake ground motion shall be determined according to the design earthquake groups and the site class of the building site. The design earthquakes in this code are totally divided into three groups, and their characteristic periods shall be adopted according to the relevant provisions in Chapter 5 of this code.
3.2.4 The seismic precautionary intensity, design basic acceleration of ground motion and design earthquake groups of the central areas in the main cities in China may be adopted according to Appendix A of this code.
Contents of GB 50011-2010
Contents
Chapter 1 General
Chapter 2 Terms and Symbols
2.1 Terms
2.2 Symbols
Chapter 3 Basic Requirements of Seismic Design
3.1 Category and Criterion for Seismic Precaution of Buildings
3.2 Earthquake Effect
3.3 Site and Base
3.4 Regularity of Building Configuration and Structural Assembly
3.5 Structural System
3.6 Structural Analysis
3.7 Nonstructural Components
3.8 Isolation and Energy-Dissipation
3.9 Materials and Construction
3.10 Performance-Based Design of Buildings
3.11 Seismic Response Observation System of Buildings
Chapter 4 Site, Base and Foundation
4.1 Site
4.2 Natural Base and Foundation
4.3 Liquefied Soil and Soft Soil Bases
4.4 Pile Foundations
Chapter 5 Earthquake Action and Seismic Checking for Structures
5.1 General
5.2 Calculation of Horizontal Earthquake Action
5.3 Calculation of Vertical Earthquake Action
5.4 Section Seismic Check
5.5 Seismic Deformation Check
Chapter 6 Multi-storey and Tall Reinforced Concrete Buildings
6.1 General
6.2 Essentials in Calculation
6.3 Details of Seismic Design for Frame Structures
6.4 Details of Seismic Design for Seismic Wall Structures
6.5 Details of Seismic Design for Frame-seismic Wall Structures
6.6 Requirements for Seismic Design of Slab-column-seismic Wall Structures
6.7 Requirements for Seismic Design of Tube Structures
Chapter 7 Multi-storey Masonry Buildings and Multi-storey Masonry Buildings with R.C. Frames on Ground Floors
7.1 General
7.2 Essentials in Calculation
7.3 Details of Seismic Design of Multi-storey Brick Buildings
7.4 Details of Seismic Design of Multi-storey Concrete Block Buildings
7.5 Details of Seismic Design of Multi-storey Masonry Buildings with R.C. Frames on Ground Floors
Chapter 8 Multi-Storey and Tall Steel Buildings
8.1 General
8.2 Essentials in Calculation
8.3 Details for Steel Frame Structures
8.4 Details of Seismic Design of Steel Frame-concentrically-supported Structures
8.5 Details for Seismic Design of Steel Frame-eccentrically-supported Structures
Chapter 9 Single-storey Factory Buildings
9.1 Single-storey Factory Buildings with R.C. Columns
9.2 Single-storey Steel Factory Buildings
9.3 Single-storey Factory Buildings with Brick Columns
Chapter 10 Large-span Buildings
10.1 Single-storey Spacious Buildings
10.2 Large-span Roof Buildings
Chapter 11 Earth, Wood and Stone Houses
11.1 General
11.2 Unfired Earth Houses
11.3 Wood Houses
11.4 Stone Houses
Chapter 12 Seismically Isolated and Energy-Dissipated Buildings
12.1 General
12.2 Essentials in Design of Seismically Isolated Buildings
12.3 Essentials in Design of Energy-dissipated Buildings
Chapter 13 Nonstructural Components
13.1 General
13.2 Essentials in Calculation
13.3 Essential Measures for Architectural Members
13.4 Essential Measures for Supports of Mechanical and Electrical Components
Chapter 14 Subterranean Buildings
14.1 General
14.2 Essentials in Calculation
14.3 Details and Anti-Liquefaction Measures
Appendix A The Seismic Precautionary Intensity, Design Basic Acceleration of Ground Motion and Design Earthquake Groups of Main Cities in China
Appendix B Requirements for Seismic Design of High Strength Concrete Structures
Appendix C Requirements for Seismic Design of Prestressed Concrete Structures
Appendix D Section Seismic Check for the Beam-column Joint Core Zone of Frames
Appendix E Requirements for Seismic Design of the Transfer Storey Structures
Appendix F Requirements for Seismic Design of Small Armored Concrete Hollow Block Buildings with Seismic Wall
Appendix G Requirements for Seismic Design of Buildings with Steel Support-Concrete Frame Structures and Steel Frame-Armored Concrete Core Tube Structures
Appendix H Requirements for Seismic Design of Multi-storey Factory Buildings
Appendix J Earthquake Action Effect Adjustment for Transverse Plane Bent Frame of Single-storey Factory Buildings
Appendix K Seismic Check for Single-storey Factory Buildings in Longitudinal Direction
Appendix L Simplified Calculation of Seismic Isolation Design and Seismic Isolation Measures for Masonry Structures
Appendix M Reference Methods for Achieving Performance-Based Seismic Design
Explanation of Wording in This Code
List of Quoted Standards
