Detail of GB/T 50779-2022

Introduction of GB/T 50779-2022

Announcement of the Ministry of Housing and Urban-Rural Development of the People's Republic of China [2022] No. 139 Announcement of the Ministry of Housing and Urban-Rural Development of the People's Republic of China on publishing the national standard Standard for blast resistant design of buildings in petrochemical engineering Standard for blast resistant design of buildings in petrochemical engineering has been approved as a national standard with serial number of GB/T 50779-2022, and shall be implemented from Thursday, December 1, 2022. The former national standard GB 50779-2012 Code for design of blast resistant control building in petrochemical industry shall be abolished simultaneously. Ministry of Housing and Urban-Rural Development of the People's Republic of China September 8, 2022   Foreword According to the requirements of Document JIANBIAO [2016] No. 248 issued by the Ministry of Housing and Urban-Rural Development of the People's Republic of China — Notice on printing and distributing the development, revision and related work plan on engineering construction standards and codes in 2017, the drafting group has formed this standard by revising the original standard GB 50779-2012 Code for design of blast resistant control building in petrochemical industry through the extensive investigation and study, careful summarization of practical experience and reference to relevant international and foreign advanced standards and on the basis of widely soliciting for opinions. The main technical contents of this standard are general provisions, terms and symbols, basic requirements, blast load, architecture design, structure design, ventilation and air conditioning design, blast resistant design of existing buildings, etc. The main contents of the revision of this standard are as follows: 1. The scope of blast resistant design has been enlarged, and the blast resistant design of petrochemical control room has been modified to the blast resistant design of buildings in petrochemical engineering; 2. The relevant requirements for the layout of blast resistant buildings, the storey number of and the height of blast resistant building have been modified and added; 3. The selection principle of structure form of blast resistant buildings under different blast loads and the blast resistant design content of masonry and steel structural buildings have been added; 4. The action time of peak incident side-on overpressure of blast shock wave and the corresponding positive pressure specified in the original code has been deleted, and it has been clarified that the positive pressure of shock wave shall be determined by blast safety assessment; 5. The relevant contents of blast load calculation and the performance requirements of blast resistant building have been modified and supplemented; 6. The structure and deformation requirements of reinforced concrete member, reinforced masonry component and steel structure member have been modified and supplemented, as well as the calculation of dynamic strength of materials, strength and dynamic improvement coefficient, and the requirements of dynamic design stress of steel bars; 7. The calculation of ductility ratio and average inertia moment of member have been modified and supplemented; 8. The in-plane and out-of-plane calculation requirements of roof panels, sidewalls and other members, as well as the checking calculation requirements of shear bearing capacity and the calculation method of direct shear bearing capacity for reinforced concrete member and reinforced masonry component have been added; 9. The equivalent static load method has been deleted, and the closed solution method has been added to the dynamic analysis of members; 10. Clause 8 "Blast resistant design of existing buildings" has been added; 11. The design requirements of fire-fighting and rescue service in blast resistant buildings, the start-stop requirements of ventilation and air conditioning equipment under normal and abnormal conditions, the performance requirements of blast resistant valves and electric sealing valves, and the height requirements of fresh air intake ports have been added. The Ministry of Housing and Urban-Rural Development of the People's Republic of China is in charge of the administration of this standard. Standard for blast resistant design of buildings in petrochemical engineering 1 General provisions 1.0.1 This standard is formulated with a view to unifying blast resistant design of buildings in petrochemical engineering for safety, reliability, technological advancement, economy and rationality. 1.0.2 This standard is applicable to blast resistant design of constructed, extended and renovated buildings in petrochemical engineering. 1.0.3 In addition to the requirements of this standard, the blast resistant design of buildings in petrochemical engineering shall also meet the requirements of the current relevant standards of the nation. 2 Terms and symbols 2.1 Terms 2.1.1 blast resistant building building designed for blast resistance based on the parameters of blast shock wave determined by blast safety assessment, in order to protect the personnel and facilities therein and reduce the impact of external blast accidents on production and operation 2.1.2 shock wave longitudinal wave with strong discontinuity surface of air parameters formed by blast in air, which is herein after referred to as shock wave 2.1.3 positive pressure of shock wave pressure on the surface of shock wave encircled objects in normal direction that is greater than the surrounding atmospheric pressure within the range of shock wave compression zone 2.1.4 dynamic pressure effect produced by the rapid movement of gas molecules in the shock wave, which has a clear direction, when the shock wave propagates in the air 2.1.5 reflected overpressure overpressure increment caused by shock wave reflected on the surface, when a shock wave encounters an obstacle in its propagation direction 2.1.6 stagnation pressure positive pressure and dynamic pressure of shock wave on the front wall, when the reflected overpressure of the front wall dissipates completely 2.1.7 peak incident side-on overpressure positive pressure of shock wave when it propagates outward from the blast center in free air and reaches the surface nearest to the blast center 2.1.8 ductility ratio ratio of elastic-plastic deformation to elastic ultimate deformation of members, which indicates the energy absorption capacity of structural members 2.1.9 primary structural member structural member that the structure depends on in the ultimate state of the bearing capacity, and the failure of which will affect the stability of other members supported by it and the whole structure of the building composed of frame column, frame beam, load-bearing wall, roof primary beam or steel structural truss, etc. 2.1.10 secondary structural member load-bearing member supported by primary structural member and non-load-bearing member directly subjected to the positive pressure of blast shock wave outside the building composed of non-load-bearing exterior wall, exterior wall panel, roof panel, roof secondary beam, etc. 2.1.11 reinforced masonry component masonry component reinforced by the reinforced block masonry, composite brick masonry and masonry members with reinforcing materials such as blast resistant coating 2.1.12 blast resistant door special door of building that resists blast shock wave from the outside of building, including blast resistant access door, blast resistant equipment door and blast resistant fire-fighting and rescue service door 2.1.13 blast resistant access door blast resistant door used for personnel to enter or exit the building normally 2.1.14 blast resistant equipment door blast resistant door used for large-scale equipment to enter or exit the building 2.1.15 blast resistant fire-fighting and rescue service door blast resistant door used for fire-fighting and rescue service 2.1.16 blast resistant window special external window for building that resists blast shock wave from outside the building 2.1.17 air lock built-in compartment on the access that blocks the positive pressure of shock wave from entering the room 2.1.18 blast resistant valve valve equipped on the opening of blast resistant building that resists blast shock wave from the outside of the building 2.1.19 manned building (room) building (room) with permanent personnel positions in the production process 2.2 Symbols 2.2.1 Material properties Ee——the elastic modulus of concrete; Es——the elastic modulus of steel bar; fcd——the design value of dynamic compressive strength of concrete; fdst——the ultimate value of dynamic strength of steel bar; fvd——the design value of dynamic shear strength of reinforced masonry; fy——the yield strength of steel; fyd——the dynamic design stress of bent steel bar; fd——the design value of dynamic strength of material; fstk——the characteristic value of ultimate strength of steel bar; fk——the characteristic value of material strength; 2.2.2 Actions, action effects and bearing capacity Ft——the force acting on member (at different time points); P——the blast load acting on member; Pa——the effective positive pressure of shock wave acting on sidewall and roof; Patm——the standard atmospheric pressure of environment; Pb——the effective positive pressure of shock wave acting on backwall; Pr——the peak reflected overpressure; Ps——the stagnation pressure; Pso——the peak incident side-on overpressure of blast shock wave; qo——the peak dynamic pressure; R——the design resistance of structural member; Ru——the ultimate resistance of structural member; Sd——the effect design value of action combination; SBK——the blast load effect; S_(G_k )——the load effect calculated using the characteristic value Gk of permanent load; S_(Q_ik )——the load effect calculated using the characteristic value Qik of variable load; V——the direct shear bearing capacity of member; Vm——the direct shear bearing capacity provided by member material; Vs——the direct shear bearing capacity provided by bent steel bar; γ0——the importance coefficient of structure; γG——the partial coefficient of permanent load; γ_(Q_i )——the partial coefficient of variable load; γB——the partial coefficient of blast load; ψ_(Q_i )——the combination coefficient of variable load Qi. 2.2.3 Geometric parameters b——the width of member section; B——the dimension of the building perpendicular to the direction of shock wave; c——the height of compression zone; h0——the effective height of member section; h——the height of member section; H——the height of building; I——the inertia moment of member section; Ia——the average inertia moment of member section; Icr——the inertia moment of cracking section; k——the rigidity of member; L——the dimension of building parallel to the direction of shock wave; L0——the span or height of member; L1——the length of structural member in heading direction of shock wave; S——the distance from the stagnation pressure point to the edge of building; Xm——the elastic-plastic deformation of member; Xy——the elastic ultimate deformation of member; y——the displacement of mass point. 2.2.4 Coefficients of calculation and others a——the acceleration of mass point motion; As——the area of member reinforcement; Asb——the area of bent steel bars; C——the deformation limit of structural member Cd——the drag coefficient; Ce——the equivalent peak pressure coefficient; Cr——the reflection coefficient; KL——the load coefficient; KLm——the load-mass coefficient; Km——the mass coefficient; Lw——the wavelength of the shock wave; m——the member mass; Me——the equivalent mass of member; n——the conversion factor of reinforced concrete member section; ta——the time for shock wave reaching backwall; tc——the duration of reflected overpressure; td——the action time of positive pressure of blast shock wave; te——the equivalent action time of positive pressure of shock wave on front wall; tr——the rising time of effective positive pressure of shock wave on sidewall and roof; trb——the rising time of effective positive pressure of shock wave on backwall; Td——the effective action time of blast load; Tm——the relevant action time of the maximum displacement; TN——the natural vibration period of member; U——the wave velocity; γdif——the dynamic improvement coefficient of material strength; γsif——the improvement coefficient of material strength; μ——the ductility ratio of member; θ——the bearing rotation angle of member; △ai——the allowable value of in-plane ductility ratio or bearing rotation angle; △ao——the allowable value of out-of-plane ductility ratio or bearing rotation angle; △ci——the calculated in-plane ductility ratio or bearing angle; △co——the calculated out-of-plane ductility ratio or bearing rotation angle; τ——the ratio of the effective action time of blast load to the natural vibration period of member; α——the angle at which the steel bar is bent. 3 Basic requirements 4 Blast load 5 Architecture design 6 Structure design 7 Ventilation and air conditioning design 8 Blast resistant design of existing buildings Appendix A Graphic solution method for dynamic analysis Appendix B Numerical integration method for dynamic analysis Appendix C Dynamic calculation factors for single degree of freedom members under several supporting conditions and load cases Appendix D Blast painting reinforcing method Explanation of wording in this standard List of quoted standards Addition: Explanation of provisions

Contents of GB/T 50779-2022

Foreword ii 1 General provisions 2 Terms and symbols 3 Basic requirements 4 Blast load 5 Architecture design 6 Structure design 7 Ventilation and air conditioning design 8 Blast resistant design of existing buildings Appendix A Graphic solution method for dynamic analysis Appendix B Numerical integration method for dynamic analysis Appendix C Dynamic calculation factors for single degree of freedom members under several supporting conditions and load cases Appendix D Blast painting reinforcing method Explanation of wording in this standard List of quoted standards Addition: Explanation of provisions