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.
In order to adapt to the general rules of international technical regulations and technical standards, since 2016, the Ministry of Housing and Urban-Rural Development has successively issued documents such as Opinions on Furthering the Reform of Standardization of Engineering Construction, which put forward the long-term goal for the government to develop mandatory standards and for social organizations to develop voluntary standards and define the reform task of gradually replacing the mandatory provisions scattered in current standards with full-text mandatory engineering construction codes, gradually forming a "technical regulations" system composed of technical provisions in laws, administrative regulations and departmental rules and full-text mandatory engineering construction codes.
About the types of codes. The mandatory engineering construction code system covers all kinds of construction projects in the field of engineering construction, namely, engineering project codes (hereinafter referred to as project codes) and general technical codes (hereinafter referred to as general codes). A project code takes the whole engineering construction project as the object, with five major factors, namely, project scale, layout, function, performance and key technical measures, as the main content. A general code takes the general technology of each discipline to meet the function and performance requirements of the engineering construction project as the object, with the general technical requirements such as survey, design, construction, repair and maintenance as the main content. In the full-text mandatory engineering construction code system, the project codes are the core, while the general codes specify the common and general professional key technical measures for all kinds of projects.
About the five major factor indicators. The factors in the mandatory engineering construction codes are the basic provisions to ensure the systematization and efficiency improvement of urban and rural infrastructure construction, and the basic requirements to support the high-quality development of urban and rural construction. The scale requirements for a project mainly stipulate that a construction project shall have complete production or service capacity and shall adapt to the level of economic and social development. The layout requirements for the project mainly stipulate the industrial layout, site selection, overall design, general layout and integrated technical requirements coordinated with the scale for the construction project. Reasonable distribution of supply capacity shall be considered to improve the overall level of related facilities construction. The function requirements of the project mainly stipulate the composition and purpose of the project and clarify the basic components of the project, which are the guarantee for the project to play its expected role. The performance requirements of the project mainly stipulate the construction level or technical level of the construction project, reflect the applicability of the construction project, and define the basic levels that the project shall achieve in the aspects of quality, safety, energy conservation, environmental protection, livable environment and sustainable development. Key technical measures are the basic technical regulations for realizing the function and performance requirements of a construction project, and they are the basic guarantee for achieving the development goals of urban and rural construction such as safety, green, resilience, wisdom, livability, fairness and efficiency.
About the implementation of codes. Mandatory engineering construction codes have mandatory binding force, which specify the control requirements and bottom lines for ensuring people's life and property safety, personal health, engineering safety, ecological environment safety, public rights and interests as well as promoting energy and resource conservation and meeting economic and social management, and they must be strictly implemented in the whole process of construction activities such as survey, design, construction, acceptance, repair, maintenance and demolition of engineering construction projects. For existing building renovation projects (where existing use functions are not changed), the stringency of the code implemented shall not be inferior to that implemented in construction if the conditions are not available and it is really difficult to implement the current codes. The voluntary engineering construction standards matching with the mandatory engineering construction codes are mature technical measures that have been tested by practice and guarantee to meet the requirements of the mandatory codes, and they shall also be implemented under normal circumstances. On the premise of meeting the project function and performance requirements and key technical measures stipulated in mandatory engineering construction codes, relevant group standards and enterprise standards may be reasonably selected to optimize the project function and performance or improve their levels. Voluntary engineering construction standards, group standards and enterprise standards shall be coordinated and match with mandatory engineering construction codes, and all technical requirements shall not be lower than the relevant technical levels of mandatory engineering construction codes.
After the implementation of a mandatory engineering construction code, the mandatory provisions in the current national standards and professional standards for relevant engineering construction shall be abolished at the same time. The mandatory provisions in the current provincial standards for engineering construction shall be revised in time, and shall not be less stringent than the provisions of the mandatory engineering construction codes. If the relevant provisions in current engineering construction standards (including mandatory and voluntary ones), are inconsistent with those of the mandatory engineering construction codes, the provisions of the mandatory engineering construction codes shall prevail.
Contents
1 General provisions 1
2 Basic requirements 2
3 Materials 4
4 Design 6
4.1 Structural systems 6
4.2 Design of members 7
4.3 Design of connections 8
4.4 Seismic and wind-resistant design 9
5 Protection and fire protection 11
5.1 Waterproof and moisture-proof measures 11
5.2 Termite protection 11
5.3 Decay/corrosion prevention 13
5.4 Fire protection 14
6 Construction and acceptance 15
7 Maintenance and demolition 17
1 General provisions
1.0.1 This code is formulated to ensure the quality and safety of timber structure engineering, implement the policies of resource conservation and environmental protection, ensure the safety of people's lives and property and personal health, and improve the sustainable development level of timber structure engineering.
1.0.2 For timber structure engineering, this code must be implemented.
1.0.3 Whether the technical methods and measures adopted in the engineering construction meet the requirements of this code shall be judged by the relevant responsibility subjects. Innovative technical methods and measures shall be demonstrated and meet the performance requirements in this code.
2 Basic requirements
2.0.1 The safety level of any timber structure and its members shall be at least of Level 3. Where the safety levels of the structure members and components are inconsistent with that of the structure, they shall be clearly indicated in the design documents.
2.0.2 The design service life of a timber structure shall meet the following requirements:
1 It shall not be less than 50 years for the timber structure of a building or structure;
2 It shall not be less than 30 years for the timber structure of a bridge;
3 It shall not be less than 25 years for structure members and components that are easy to replace;
4 If the design service life of members and components of a timber structure is less than that of the structure, it shall be clearly indicated in the design documents, and the connection structures that are easy to replace shall be used.
2.0.3 The performance of a timber structure within its design service life shall meet the following requirements:
1 The structure shall be able to withstand various actions that may occur in normal construction and normal use;
2 The structure shall be able to meet the requirements for the intended use of the structure and its structure members;
3 The durability of the material shall allow the structure to resist the long-term damage from both itself and natural environment;
4 In the case of a fire, the structure shall maintain sufficient bearing capacity and overall stability within the specified time;
5 If an accident such as explosion, impact, rare earthquake or human error occurs, the structure shall maintain the overall stability.
2.0.4 The use and maintenance of a timber structure within its design service life shall meet the following requirements:
1 Without technical appraisal or design permission, the functions and use conditions specified in the design shall not be changed;
2 For matters that may affect the safety and durability of the main structure, a regular testing and maintenance system shall be established;
3 Members, nodes, supports, anchorages and components that must be replaced according to the design regulations shall be replaced in time;
4 The protective layers on the surface of the members shall be maintained or replaced as required;
5 In the case of visible deformation or any durability defects in the structure and its members, nodes and supports, repair and reinforcement shall be conducted in time;
6 In the case of an earthquake within fortification intensity or any earthquake disaster or fire above that intensity, the overall structure shall be appraised, and only after it is treated according to the appraisal opinions can it continue to be used.
2.0.5 The design, construction, supervision, testing, supervision and other work of timber structure engineering shall be subject to unified measurement standards; during the construction of a timber structure, the structural bearing capacity and stability in each construction process and stage shall be subjected to checking calculation.
3 Materials
3.0.1 Timber structures shall be made of square timber, log, sawn timber and engineered wood products with clear material grades or strength grades.
3.0.2 The moisture content of structural lumber shall meet the requirements of design, manufacture and installation of the timber structures.
3.0.3 The design strength of structural lumber shall meet the following requirements:
1 The design strength of structural lumber shall be determined by the standard strength and the partial safety factor for resistance, and the influence of load duration on the lumber strength shall be taken into account;
2 The partial safety factor for resistance shall be determined according to the target reliability index and the deviation coefficient of tenacity of the lumber.
3.0.4 The strength design index of structural lumber shall be adjusted according to the size of timber members, service conditions, design service life and other factors of the structure.
3.0.5 The steel used in a timber structure shall meet the following requirements:
1 The steel shall be provided with assurance of conformity for tensile strength, yield strength, elongation after fracture and content of carbon, sulfur and phosphorus;
2 The steel used for the welded structures requiring fatigue checking calculation shall be provided with assurance of conformity for impact ductility;
3 The steel with lamellar tearing resistance in the thickness direction required by the design shall be provided with assurance of conformity for reduction of area;
4 During seismic design, the yield ratio and elongation after fracture of steel shall meet the requirements for plastic design of steel structure.
3.0.6 Metal connectors used in a timber structure shall not only meet the requirements of 3.0.5, but also be provided with product quality certificates, and cast steel connectors shall also be provided with assurance of conformity for reduction of area. Stainless steel connectors shall also be provided with assurance of conformity for nominal yield strength, tensile strength, elongation and the content of carbon, nickel, chromium and molybdenum.
3.0.7 The type of structural adhesive shall meet the requirements of the service environment, and its bonding performance shall meet the strength and durability indexes required in the design.
3.0.8 The fiber, matrix material and interface bonding performance used in timber structure improvement or reinforcement shall meet the requirements of strength, durability and ambient temperature and humidity.
1 General provisions
2 Basic requirements
3 Materials
4 Design
4.1 Structural systems
4.2 Design of members
4.3 Design of connections
4.4 Seismic and wind-resistant design
5 Protection and fire protection
5.1 Waterproof and moisture-proof measures
5.2 Termite protection
5.3 Decay/corrosion prevention
5.4 Fire protection
6 Construction and acceptance
7 Maintenance and demolition
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.
In order to adapt to the general rules of international technical regulations and technical standards, since 2016, the Ministry of Housing and Urban-Rural Development has successively issued documents such as Opinions on Furthering the Reform of Standardization of Engineering Construction, which put forward the long-term goal for the government to develop mandatory standards and for social organizations to develop voluntary standards and define the reform task of gradually replacing the mandatory provisions scattered in current standards with full-text mandatory engineering construction codes, gradually forming a "technical regulations" system composed of technical provisions in laws, administrative regulations and departmental rules and full-text mandatory engineering construction codes.
About the types of codes. The mandatory engineering construction code system covers all kinds of construction projects in the field of engineering construction, namely, engineering project codes (hereinafter referred to as project codes) and general technical codes (hereinafter referred to as general codes). A project code takes the whole engineering construction project as the object, with five major factors, namely, project scale, layout, function, performance and key technical measures, as the main content. A general code takes the general technology of each discipline to meet the function and performance requirements of the engineering construction project as the object, with the general technical requirements such as survey, design, construction, repair and maintenance as the main content. In the full-text mandatory engineering construction code system, the project codes are the core, while the general codes specify the common and general professional key technical measures for all kinds of projects.
About the five major factor indicators. The factors in the mandatory engineering construction codes are the basic provisions to ensure the systematization and efficiency improvement of urban and rural infrastructure construction, and the basic requirements to support the high-quality development of urban and rural construction. The scale requirements for a project mainly stipulate that a construction project shall have complete production or service capacity and shall adapt to the level of economic and social development. The layout requirements for the project mainly stipulate the industrial layout, site selection, overall design, general layout and integrated technical requirements coordinated with the scale for the construction project. Reasonable distribution of supply capacity shall be considered to improve the overall level of related facilities construction. The function requirements of the project mainly stipulate the composition and purpose of the project and clarify the basic components of the project, which are the guarantee for the project to play its expected role. The performance requirements of the project mainly stipulate the construction level or technical level of the construction project, reflect the applicability of the construction project, and define the basic levels that the project shall achieve in the aspects of quality, safety, energy conservation, environmental protection, livable environment and sustainable development. Key technical measures are the basic technical regulations for realizing the function and performance requirements of a construction project, and they are the basic guarantee for achieving the development goals of urban and rural construction such as safety, green, resilience, wisdom, livability, fairness and efficiency.
About the implementation of codes. Mandatory engineering construction codes have mandatory binding force, which specify the control requirements and bottom lines for ensuring people's life and property safety, personal health, engineering safety, ecological environment safety, public rights and interests as well as promoting energy and resource conservation and meeting economic and social management, and they must be strictly implemented in the whole process of construction activities such as survey, design, construction, acceptance, repair, maintenance and demolition of engineering construction projects. For existing building renovation projects (where existing use functions are not changed), the stringency of the code implemented shall not be inferior to that implemented in construction if the conditions are not available and it is really difficult to implement the current codes. The voluntary engineering construction standards matching with the mandatory engineering construction codes are mature technical measures that have been tested by practice and guarantee to meet the requirements of the mandatory codes, and they shall also be implemented under normal circumstances. On the premise of meeting the project function and performance requirements and key technical measures stipulated in mandatory engineering construction codes, relevant group standards and enterprise standards may be reasonably selected to optimize the project function and performance or improve their levels. Voluntary engineering construction standards, group standards and enterprise standards shall be coordinated and match with mandatory engineering construction codes, and all technical requirements shall not be lower than the relevant technical levels of mandatory engineering construction codes.
After the implementation of a mandatory engineering construction code, the mandatory provisions in the current national standards and professional standards for relevant engineering construction shall be abolished at the same time. The mandatory provisions in the current provincial standards for engineering construction shall be revised in time, and shall not be less stringent than the provisions of the mandatory engineering construction codes. If the relevant provisions in current engineering construction standards (including mandatory and voluntary ones), are inconsistent with those of the mandatory engineering construction codes, the provisions of the mandatory engineering construction codes shall prevail.
Contents
1 General provisions 1
2 Basic requirements 2
3 Materials 4
4 Design 6
4.1 Structural systems 6
4.2 Design of members 7
4.3 Design of connections 8
4.4 Seismic and wind-resistant design 9
5 Protection and fire protection 11
5.1 Waterproof and moisture-proof measures 11
5.2 Termite protection 11
5.3 Decay/corrosion prevention 13
5.4 Fire protection 14
6 Construction and acceptance 15
7 Maintenance and demolition 17
1 General provisions
1.0.1 This code is formulated to ensure the quality and safety of timber structure engineering, implement the policies of resource conservation and environmental protection, ensure the safety of people's lives and property and personal health, and improve the sustainable development level of timber structure engineering.
1.0.2 For timber structure engineering, this code must be implemented.
1.0.3 Whether the technical methods and measures adopted in the engineering construction meet the requirements of this code shall be judged by the relevant responsibility subjects. Innovative technical methods and measures shall be demonstrated and meet the performance requirements in this code.
2 Basic requirements
2.0.1 The safety level of any timber structure and its members shall be at least of Level 3. Where the safety levels of the structure members and components are inconsistent with that of the structure, they shall be clearly indicated in the design documents.
2.0.2 The design service life of a timber structure shall meet the following requirements:
1 It shall not be less than 50 years for the timber structure of a building or structure;
2 It shall not be less than 30 years for the timber structure of a bridge;
3 It shall not be less than 25 years for structure members and components that are easy to replace;
4 If the design service life of members and components of a timber structure is less than that of the structure, it shall be clearly indicated in the design documents, and the connection structures that are easy to replace shall be used.
2.0.3 The performance of a timber structure within its design service life shall meet the following requirements:
1 The structure shall be able to withstand various actions that may occur in normal construction and normal use;
2 The structure shall be able to meet the requirements for the intended use of the structure and its structure members;
3 The durability of the material shall allow the structure to resist the long-term damage from both itself and natural environment;
4 In the case of a fire, the structure shall maintain sufficient bearing capacity and overall stability within the specified time;
5 If an accident such as explosion, impact, rare earthquake or human error occurs, the structure shall maintain the overall stability.
2.0.4 The use and maintenance of a timber structure within its design service life shall meet the following requirements:
1 Without technical appraisal or design permission, the functions and use conditions specified in the design shall not be changed;
2 For matters that may affect the safety and durability of the main structure, a regular testing and maintenance system shall be established;
3 Members, nodes, supports, anchorages and components that must be replaced according to the design regulations shall be replaced in time;
4 The protective layers on the surface of the members shall be maintained or replaced as required;
5 In the case of visible deformation or any durability defects in the structure and its members, nodes and supports, repair and reinforcement shall be conducted in time;
6 In the case of an earthquake within fortification intensity or any earthquake disaster or fire above that intensity, the overall structure shall be appraised, and only after it is treated according to the appraisal opinions can it continue to be used.
2.0.5 The design, construction, supervision, testing, supervision and other work of timber structure engineering shall be subject to unified measurement standards; during the construction of a timber structure, the structural bearing capacity and stability in each construction process and stage shall be subjected to checking calculation.
3 Materials
3.0.1 Timber structures shall be made of square timber, log, sawn timber and engineered wood products with clear material grades or strength grades.
3.0.2 The moisture content of structural lumber shall meet the requirements of design, manufacture and installation of the timber structures.
3.0.3 The design strength of structural lumber shall meet the following requirements:
1 The design strength of structural lumber shall be determined by the standard strength and the partial safety factor for resistance, and the influence of load duration on the lumber strength shall be taken into account;
2 The partial safety factor for resistance shall be determined according to the target reliability index and the deviation coefficient of tenacity of the lumber.
3.0.4 The strength design index of structural lumber shall be adjusted according to the size of timber members, service conditions, design service life and other factors of the structure.
3.0.5 The steel used in a timber structure shall meet the following requirements:
1 The steel shall be provided with assurance of conformity for tensile strength, yield strength, elongation after fracture and content of carbon, sulfur and phosphorus;
2 The steel used for the welded structures requiring fatigue checking calculation shall be provided with assurance of conformity for impact ductility;
3 The steel with lamellar tearing resistance in the thickness direction required by the design shall be provided with assurance of conformity for reduction of area;
4 During seismic design, the yield ratio and elongation after fracture of steel shall meet the requirements for plastic design of steel structure.
3.0.6 Metal connectors used in a timber structure shall not only meet the requirements of 3.0.5, but also be provided with product quality certificates, and cast steel connectors shall also be provided with assurance of conformity for reduction of area. Stainless steel connectors shall also be provided with assurance of conformity for nominal yield strength, tensile strength, elongation and the content of carbon, nickel, chromium and molybdenum.
3.0.7 The type of structural adhesive shall meet the requirements of the service environment, and its bonding performance shall meet the strength and durability indexes required in the design.
3.0.8 The fiber, matrix material and interface bonding performance used in timber structure improvement or reinforcement shall meet the requirements of strength, durability and ambient temperature and humidity.
Contents of GB 55005-2021
1 General provisions
2 Basic requirements
3 Materials
4 Design
4.1 Structural systems
4.2 Design of members
4.3 Design of connections
4.4 Seismic and wind-resistant design
5 Protection and fire protection
5.1 Waterproof and moisture-proof measures
5.2 Termite protection
5.3 Decay/corrosion prevention
5.4 Fire protection
6 Construction and acceptance
7 Maintenance and demolition
