PROFESSIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA. ~~A~~~!Etr~il'tt

Transcription

1 UDC PROFESSIONAL STANDARD OF Jl[GJI THE PEOPLE'S REPUBLIC OF CHINA ~~A~~~!Etr~il'tt p JGJ Record Number: J Technical Specification for High Strength Bolt Connections of Steel Structures Issued on: January 7, 2011 Implemented on: October 1, 2011 Issued by Ministry of Housing and Urban-Rural Development of the People's Republic of China

2 Foreword According to the requirements of Document Jian Biao [2004] No. 66 issued by the former Ministry of Construction (MOC)-"Notice on Printing and Distributing 'the Development and Revision Plan of National Engineering Construction Standards in 2004"', the drafting group of this specification revised this specification through the extensive investigation and study, by earnestly summing up and accumulating the experiences in actual practices, by reference to the relevant international standards and foreign advanced standards, as well as on the basis of widely soliciting opinions. The main technical contents of this Specification are: 1. General Provisions; 2. Terms and Symbols; 3. Basic Requirements; 4. Design of Connections; 5. Design of Joints; 6. Construction; 7. Acceptance of Construction Quality. Main technical contents revised in this Specification: 1. Contents were added and adjusted: former 3 chapters were added and adjusted to 7 chapters; Chapter 2 "Terms and Symbols", Chapter 3 "Basic Requirements" and Chapter 5 "Design of Joints" were added; former Chapter 2 "Design of Connections" was adjusted to Chapter 4, former Chapter 3 "Construction and Acceptance" was adjusted to Chapter 6 "Construction" and Chapter 7 "Acceptance of Construction Quality"; 2. Hole pattern coefficients were added; standard hole, large circular hole and slotted hole were introduced; 3. Coating faying surface and its mean slip coefficient µ were added; 4. Tension joints and end plate joints were added; prying force calculation method was proposed; 5. Joints combined bolts and welds were added; 6. Tum-of-nut method construction and inspection were added; 7. High strength bolt connection subitem project inspection batch was detailed and specified definitely. The provisions printed in bold type in this Specification are compulsory and must be enforced strictly. The Ministry of Housing and Urban-Rural Development of the People's Republic of China in charge of the administration of this Specification and the explanation of the compulsory provisions; Central Research Institute of Building and Construction, MCC Group Co., Ltd. is responsible for the explanation of specific technical contents. During the process of implementing this Specification, the relevant opinions and advice, whenever necessary, can be posted or passed on to Central Research Institute of Building and Construction, MCC Group Co., Ltd. (Address: No. 33, Xitucheng Road, Haidian District, Beijing , China). Chief Development Organization: Central Research Institute of Building and Construction, MCC Group Co., Ltd. Pa1ticipating Development Organizations: National Steel Structure Engineering Technology Research Center China Academy of Railway Science MCC Capital Engineering & Research Incorporation Limited Baotou Engineering and Research Corporation of Iron and Steel Industry Tsinghua University

3 Contents General Provisions Terms and Symbols Terms Sy1nbols Basic Requirements General Requirements Materials and Design Indices Design of Connections Slip Critical Connections... 9 ' 4.2 Bearing Type Connections Connection Details Design of Joints Splice Joints T-type Tension Joints Construction Acceptance of Construction Quality Explanation of Wording in This Specification List of Quoted Standards

4 2 Terms and Symbols 2.1 Terms Heavy-hex high strength bolt assembly It refers to the assembly of connecting fastener composed of one heavy-hex high strength bolt, one heavy-hex high strength nut and two high strength plain steel washers Twist-off-type high strength bolt assembly It refers to the assembly of connecting fastener composed of one twist-off-type high strength bolt, one heavy-hex high strength nut and one high strength plain steel washer Faying surface It refers to the contact surface between high strength bolt connection slabs Pretension It refers to the tension produced along bolt shank axis direction by tightening high strength bolt assembly and required to meet the connection design Friction-type joint It refers to the connecting mode generating frictional resistance among connected pieces by high strength bolts tightening to transfer shear force and integrate components, units or plates Bearing-type joint It refers to the connecting mode adopting screw rod shear and hole wall pressure bearing to transfer shear force and integrate components, units or plates Prying action It refers to the additional pressure generated at the edge of connecting pieces due to connecting piece deformation and joint lever action caused by tensile load and bolt shaft axis deviation in the T-type tension joints Mean slip coefficient It refers to the ratio of external slip force to normal pressure (identical to the bolt pretension) in connection during the slip of faying surface of high strength bolt connections Torque-pretension coefficient It refers to the scale coefficient between the tightening torque applied on the nut and lead-in axial pretension (tightening axial force) on the bolt in the high strength bolt connections Connection of sharing on a shear load by bolts and welds It refers to the joint type designed considering that friction-type high strength bolt connections and fillet weld share the same shear force Joint with combined bolts and welds 2

5 It refers to the joint type that flange adopts penetration weld connection and web adopts frictiontype high strength bolt connection in the splice nodes of beam, column and suppotiing components as well as mutual connecting nodes Calibrated wrench method It refers to the tightening method for high strength bolt assembly by controlling the construction torque values Tum-of-nut method It refers to the tightening method for high strength bolt assembly by controlling the relative corner values of bolt and nut. 2.2 Symbols Action and action effect F-- Concentrated load; M--Bending moment; N--Concentric force; P--Pretension of high strength bolt; Q--Prying force; V--Shear force Calculation indices }--Design values of tensile, compression and bending strength of steels; fcb --Design value of bearing strength of high strength bolt connecting piece; J;b--Design value of tensile strength of high strength bolt; fv--design value of shear strength of steel; f vb --Design value of shear strength of high strength bolt; N:--Design value of compression bearing capacity of single high strength bolt; N 1 b --Design value of tensile bearing capacity of single high strength bolt; N~ --Design value of shear bearing capacity of single high strength bolt; CJ-- Normal stress; r--shear stress Geometric parameters A--Gross sectional area; 3

6 3 Basic Requirements 3.1 General Requirements As for the design of high strength bolt connections, ultimate state design method based on probability theory shall be adopted; as for the calculation, partial coefficient design expression shall be adopted. Except the fatigue calculation, high strength bolt connections shall be designed according to the following ultimate state criteria: 1 Ultimate bearing capacity state shall meet the following requirements: 1) Connecting pieces of shear-resistant friction-type connection shall generate relative slip; 2) Bolts or connecting pieces of shear-resistant bearing-type connection shall reach shear strength or bearing strength; 3) Bolts or connecting pieces of tension connection along bolt shank axis direction shall reach tensile strength; 4) Bolts or connecting pieces of connection required seismic checking calculation shall reach ultimate bearing capacity. 2 Ultimate normal use state shall meet the following requirements: 1) Connecting pieces of shear-resistant bearing-type connection shall generate relative slip; 2) Connecting pieces of tension connection along bolt shank axis direction shall generate relative separation Design of high strength bolt connections should meet the principle connection strength not less than that of component. In the steel structure design documents, it shall be noted that prope1ty grade, specification and connection type of high strength bolt assembly as well as mean slip coefficient value of friction-type connection faying surface Bearing-type high strength bolt connections shall not be used for the component connection directly bearing the repeating action of dynamic loads and requiring the fatigue calculation, or the component connection whose connection deformation is sensitive to the influence of structural bearing capacity and rigidity. Bearing-type high strength bolt connections should not be used for the cold-shaped thin-walled steel component connection Where high strength bolt connections suffer above l 50 C radiant heat (ambient temperature) for a long time or suffer flame action in a short time, they shall be protected by heat insulation and temperature reduction measures. Where the components are protected from fire by fire retardant coating, the coating thickness at the high strength bolt joint shall not be less than that of adjacent components. Where the ambient temperature of high strength bolt connections is l00 C~ ls0 C, capacity shall reduce by 10%. the bearing As for the high strength bolt connections directly bearing the repeating action of dynamic 5

7 loads, where the cycle times of stress variation is equal to or greater than 5x 10 4, fatigue checking calculation shall be carried out according to the relevant requirements of the cunent national standard "Code for Design of Steel Structures" GB and shall meet the following principles: 1 Fatigue checking calculation may be omitted for shear-resistant friction-type connection, but shall be carried out for the opening base metal at the joint; 2 As for the high strength bolt connections based on the tensile along bolt axial direction under the repeating action of dynamic loads, where the bolt axial tension caused by load and prying force exceeds 30% of bolt tensile capacity, fatigue checking calculation shall be carried out on the tensile stress of bolt; 3 As for the tension connection for fatigue checking calculation, the influence of prying action shall be fall into consideration; connection rigidity strengthening measures such as increasing connecting plate thickness should be adopted to ensure that the calculated prying force does not exceed 30% of external tension of loads; 4 As for the connection of sharing on a shear load by bolts and welds, fatigue checking calculation shall be carried out on the welds according to the principle that all shear forces are assumed by the welds Where structures have seismic protection requirements, ultimate bearing capacity checking calculation and seismic structure design for high strength bolt connections shall be carried out according to the current national standard "Code for Seismic Design of Buildings" GB and relevant standards In the same joint, high strength bolt connections shall not be mixed with common bolt connections. Bearing-type high strength bolt connections shall not be combined with welded connections. 3.2 Materials and Design Indices Materials and properties of heavy-hex high strength bolt (property grade 8.8s and 10.9s) assembly shall respectively meet the requirements of current national standards "High Strength Bolts with Large Hexagon Head for Steel Structures" GB/T 1228, "High Strength Large Hexagon Nuts for Steel Structures" GB/T 1229, "High Strength Plain Washers for Steel Structures" GB/T 1230 and "Specifications of High Strength Bolts with Large Hexagon Head, Large Hexagon Nuts, Plain Washers for Steel Structures" GB/T Materials and prope1ties of twist-off-type high strength bolt (prope1ty grade 10.9s) assembly shall meet the requirements of the current national standard "Sets of Torshear Type High Strength Bolt Hexagon Nut and Plain Washer for Steel Structures" GB/T Design value of bearing-type connection strength shall be adopted according to Table Mean slip coefficient (p) values of high strength bolt connection faying surface shall be adopted according to Table and Table Pretension design value of each high strength bolt shall be adopted according to Table Ultimate bearing capacity values of high strength bolt connections shall meet the relevant 6