Detail of JT/T 391-2019

Introduction of JT/T 391-2019

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. This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard replaces JT/T 391-2009 Pot bearing for highway bridges. In addition to editorial changes, the following main technical changes have been made with respect to JT/T 391-2009: ——The definition and performance index requirements of high performance slide plates are added (see 3.1.4 and 5.3.3); ——Transverse movable bearing and transverse movable bearing of isolation type are added (see 4.1); ——The model representation method of bearing under horizontal bearing capacity is added (see 4.3); ——The requirements for the working life of pot bearings are added (see 5.1.1); ——The classification standards and test methods of horizontal bearing capacity of pot bearings are added (see 5.1.3 and Annex B); ——The technical requirements for bearing appearance are added (see 5.2); ——The bearing classification of vertical design bearing capacity 0.4MN~0.8MN is deleted (see 4.1.1 of Edition 2009); ——The bearing classification of vertical design bearing capacity 65MN~80MN is added (see 5.1.2); ——The technical requirements and test methods for anchor bolts, sleeves, screws, etc. are added (see 5.3.1 and 6.3.1); ——The acceptable appearance defects of rubber plates are modified (see 5.4.2.2; 4.4.1 of Edition 2009); ——The PTFE plate materials are deleted (see 4.2.2 of Edition 2009); ——Anti-corrosion measures for anchor bolts and sleeves are added, and anti-corrosion measures for steel parts are modified (see 5.5.5); ——The inspection rules are modified (see Clause 7; Clause 7 of Edition 2009). This standard was proposed by and is under the jurisdiction of the National Technical Committee on Traffic Engineering Facilities (Highway) of Standardization Administration of China (SAC/TC 223). The previous editions of this standard are as follows: ——JT 3141-1990; ——JT 391-1999, JT/T 391-2009. Pot bearing for highway bridge 1 Scope This standard specifies the product classification, structural forms, models, technical requirements, test methods, inspection rules as well as marking, packaging, transportation and storage of pot bearings for highway bridges. This standard is applicable to the production, inspection and use of pot bearings with design bearing capacity of 1MN~80MN for highway bridges. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 528 Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties GB/T 699 Quality carbon structure steels GB/T 700 Carbon structural steels GB/T 1040.3 Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets GB/T 1184 Geometrical tolerancing - Geometrical tolerances for features without individual tolerance indications GB/T 1591 High strength low alloy structural steels GB/T 1632.3 Plastics - Determination of the viscosity of polymers in dilute solution using capillary viscometer - Part 3: Polyethylenes and polypropylenes GB/T 1682 Rubber, vulcanized - Determination of low-temperature brittleness - Single test piece method GB/T 1804 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications GB/T 2040 Copper and copper alloy sheet GB/T 3077 Alloy structure steels GB/T 3280 Cold rolled stainless steel plate, sheet and strip GB/T 3323 Radiographic examination of fusion welded joints in metallic materials GB/T 3398.1 Plastics - Determination of hardness - Part 1: Ball indentation method GB/T 3512 Rubber, vulcanized or thermoplastic - Accelerated ageing and heat resistance tests - Air-oven method GB/T 6031 Rubber, vulcanized or thermoplastic - Determination of hardness (hardness between 10 IRHD and 100 IRHD) GB/T 7233.1 Steel castings - Ultrasonic examination - Part 1: Steel castings for general purposes GB/T 7759.1 Rubber, vulcanized or thermoplastic - Determination of compression set - Part 1: At ambient or elevated temperatures GB/T 7762 Rubber, vulcanized or thermoplastic - Resistance to ozone cracking - Static strain test GB/T 11345 Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment GB/T 11352 Carbon steel castings for general engineering purpose HG/T 2198 Vulcanized rubber - The general requirements for the physical test method HG/T 2502 5201 silicone grease JB/T 5936 Engineering machinery - General technical specifications for mechanical processed parts JB/T 5943 Construction machinery - General specifications for welding parts JT/T 722 Specifications of protective coating for highway bridge steel structure JT/T 901 Polymer materials sliding plate for bridge bearings 3 Terms, definitions and symbols 3.1 Terms and definitions For the purposes of this standard, the following terms and definitions apply. 3.1.1 pot bearing bearing using the rubber plate sealed in the steel pot to bear the dead load and live load of the superstructure and transfer the load to the sub-structure 3.1.2 working life year in which the bearing can work normally under the conditions of normal design, production, installation, operation and maintenance 3.1.3 friction plate steel plate with specified friction coefficient and energy dissipation capacity for isolation bearings 3.1.4 high performance slide plate sliding elements with self-lubricity, wear resistance and physical and mechanical properties, usually referring to modified PTFE slide plate or modified UHMWPE slide plates processed from polyethylene raw materials with average viscosity molecular weight greater than 9 million 3.2 Symbols For the purposes of this document, the following symbols apply. D——Diameter of rubber plate, mm; D1——Diameter of brass sealing ring, mm; M——Molecular weight, dimensionless; d——Diameter of high performance slide plate, mm; d1——Plane diameter of the grease storage pit of high performance slide plate, mm; d2——Diameter of steel plate for friction coefficient test, mm; μ——Friction coefficient of movable bearing; μs——Static friction coefficient of high performance slide plate; μd——Dynamic friction coefficient of high performance slide plate; η——Intrinsic viscosity number, dL/g. 4 Classification, structural forms and models 4.1 Classification 4.1.1 According to the use performance, the pot bearing for highway bridge is divided into: a) bidirectional movable bearing: with vertical bearing capacity, vertical rotation and bidirectional sliding performance, in the code of SX; b) longitudinal movable bearing: with vertical and transverse horizontal bearing capacity, vertical rotation and longitudinal sliding performance, in the code of ZX; c) transverse movable bearing: with vertical and longitudinal horizontal bearing capacity, vertical rotation and transverse sliding performance, in the code of HX; d) fixed bearing: with vertical and longitudinal/transverse horizontal bearing capacity and vertical rotation performance, in the code of GD; e) longitudinal movable bearing of isolation type: with vertical and transverse horizontal bearing capacity, vertical rotation and longitudinal sliding and isolation performance, in the code of JZZX; f) transverse movable bearing of isolation type: with vertical and longitudinal horizontal bearing capacity, vertical rotation and transverse sliding and isolation performance, in the code of JZHX; g) fixed isolation bearing: with vertical and longitudinal/ transverse horizontal bearing capacity, vertical rotation and isolation performance, in the code of JZGD. 4.1.2 According to the applicable temperature range, the bearing is divided into: a) normal temperature bearing: applicable to -25℃~+60℃, in the code of C; b) cold-resistant bearing: applicable to -40℃~+60℃, in the code of F. 4.2 Structural form 4.2.1 Bidirectional movable bearing, longitudinal movable bearing and transverse movable bearing are composed of top plate, cold rolled stainless steel plate, high performance slide plate, sealing ring of high performance slide plate, intermediate steel plate, rubber plate, brass sealing ring, steel pot, anchor bolt, sleeve, screw, rubber sealing ring, dustproof coaming, etc.; on the top plate block of the longitudinal movable bearing and transverse movable bearing, there shall be lateral cold rolled stainless steel bar, and on both sides of the corresponding intermediate steel plate, there shall be SF-1 three-layer composite plate guide slider. See Figure 1 and Figure 2 for the structure (the dustproof coaming is not given). Key 1——Top plate 6——Anchor bolt 11——Rubber plate‘ 2——Cold rolled stainless steel plate 7——Sleeve 12——Brass sealing ring 3——Sealing ring of high performance slide plate 8——Washer 13——Rubber sealing ring 4——High performance slide plate 9——Threaded rod 5——Intermediate steel plate 10——Steel pot Figure 1 Schematic diagram of bidirectional movable bearing Key 1——Top plate 9——Washer 2——Lateral cold rolled stainless steel bar 10——Sleeve 3——SF-1 three-layer composite plate guide slider 11——Threaded rod 4——Sealing ring of high performance slide plate 12——Steel pot 5——Cold rolled stainless steel plate 13——Rubber plate 6——High performance slide plate 14——Brass sealing ring 7——Intermediate steel plate 15——Rubber sealing ring 8——Anchor bolt Figure 2 Schematic diagram of longitudinal movable bearing and transverse movable bearing 4.2.2 The fixed bearing is composed of top plate, rubber plate, brass sealing ring, steel pot, anchor bolt, sleeve, threaded rod, rubber sealing ring and dustproof coaming, etc. See Figure 3 for the structure (the dustproof coaming is not given). Key 1——Top plate 6——Anchor bolt 2——Dustproof ring 7——Washer 3——Brass sealing ring 8——Steel pot 4——Rubber plate 9——Threaded rod 5——Sleeve Figure 3 Schematic diagram of fixed bearing 4.2.3 The fixed isolation bearing is composed of top plate, high damping rubber ring, upper friction plate, lower friction plate, lower lining plate, rubber plate, brass sealing ring, steel pot, anchor bolt, sleeve, threaded rod, rubber sealing ring and dustproof coaming, etc. See Figure 4 for the structure (the dustproof coaming is not given). Key 1——Top plate 7——Anchor bolt 2——High damping rubber ring 8——Washer 3——Upper friction plate 9——Steel pot 4——Lower friction plate 10——Rubber plate 10——Lower lining plate 11——Brass sealing ring 6——Sleeve 12——Threaded rod Figure 4 Schematic diagram of fixed isolation bearing 4.2.4 The longitudinal movable bearing of isolation type and transverse movable bearing of isolation type are composed of top plate, high damping rubber ring, upper friction plate, lower friction plate, cold rolled stainless steel plate, high performance slide plate, sealing ring of high performance slide plate, intermediate steel plate, rubber plate, brass sealing ring, steel pot, anchor bolt, lower lining plate, SF-1 three-layer composite plate guide slider, lateral cold rolled stainless steel bar and dustproof coaming, etc. See Figure 5 for the structure (the dustproof coaming is not given). Key 1——Top plate 10——Anchor bolt 2——Lateral cold rolled stainless steel bar 11——Sleeve 3——SF-1 three-layer composite plate guide slider 12——Threaded rod 4——Sealing ring of high performance slide plate 13——Steel pot 5——Cold rolled stainless steel plate 14——Rubber plate 6——High performance slide plate 15——Lower lining plate 7——Intermediate steel plate 16——High damping rubber ring 8——Upper friction plate 17——Brass sealing ring 9——Lower friction plate 18——Washer Figure 5 Schematic diagram of longitudinal movable bearing of isolation type and transverse movable bearing of isolation type 4.3 Models See Figure 6 for the representation method of bearing model. Figure 6 Representation method of bearing model Example 1: For the cold-resistant bidirectional movable pot bearing, designed in ××××, with vertical design bearing capacity of 15MN, transverse horizontal design bearing capacity of 10% of the vertical design bearing capacity, design displacement along the bridge of ±100mm, its mode is expressed as GPZ(××××)15-10%-SX-±100-F. Example 2: For the longitudinal movable pot bearing of normal temperature type, designed in ××××, with vertical design bearing capacity of 15MN, transverse horizontal design bearing capacity of 15% of the vertical design bearing capacity, displacement along the bridge of ±50mm, its mode is expressed as GPZ(××××)15-15%-ZX-±50-C. Example 3: For the fixed pot bearing of normal temperature type, designed in ××××, with vertical design bearing capacity of 15MN, horizontal design bearing capacity of 10% of the vertical design bearing capacity, its mode is expressed as GPZ(××××)15-10%-GD-C. Example 4: For the cold-resistant fixed isolation pot bearing, designed in ××××, with vertical design bearing capacity of 15MN, its mode is expressed as GPZ(××××)15-JZGD-F. Example 5: For the longitudinal movable pot bearing of normal temperature and isolation type, designed in ××××, with vertical design bearing capacity of 15MN and design displacement along the bridge of ±150mm, its mode is expressed as GPZ(××××)15-JZZX-±150-C.

Contents of JT/T 391-2019

Foreword i 1 Scope 2 Normative references 3 Terms, definitions and symbols 4 Classification, structural forms and models 5 Technical requirements 6 Test methods 7 Inspection rules 8 Marking, packaging, transportation and storage Annex A (Normative) Test method for vertical bearing capacity of bearings Annex B (Normative) Test method for horizontal bearing capacity of bearings Annex C (Normative) Test method for friction coefficient of bearings Annex D (Normative) Test method for bearing rotation angle Annex E (Informative) Description of bearing installation (example)