Detail of GB 20688.3-2006

Introduction of GB 20688.3-2006

Rubber bearings — Part 3: Elastomeric seismic-protection isolators for buildings 1 Scope This part specifies the requirements for elastomeric seismic-protection isolators used for buildings (herein after referred to as “elastomeric isolator”) and the requirements for the rubber material and steel plate used in the manufacture of such isolators. This part covers the classification, requirements, design rules, tolerances, inspection rules, marking and labelling for elastomeric isolators. This part is applicable to elastomeric isolators used for building structures. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part. For dated references, subsequent amendments to (excluding corrections to), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest editions apply. GB 50017-2003 Code for design of steel structures GB/T 20688.1-2007 Rubber bearings — Part 1: Seismic-protection isolators test methods ISO 22762-1:2005, MOD) 3 Terms and definitions For the purposes of this part, the following terms and definitions apply. Note: Unless otherwise specified, all bearings referred to in this part are elastomeric isolators. 3.1 breaking rupture of elastomeric isolator due to compression (or tension)-shear loading 3.2 buckling state when elastomeric isolators lose their stability under compressive-shear loading   3.3 compressive properties compressive stiffness (Kv) for all types of rubber bearings 3.4 compressive-shear testing machine machine used to test elastomeric isolators, which has the capability of shear loading under constant compressive load 3.5 cover rubber rubber wrapped around the outside of inner rubber and reinforcing steel plates 3.6 design compressive stress design adopted compressive stress acting on the elastomeric isolator 3.7 effective loaded area area sustaining vertical load in elastomeric isolators, which is equal to the plan area of inner rubber 3.8 effective width (rectangular elastomeric isolator) the smaller of the two side lengths of inner rubber 3.9 elastomeric isolator rubber bearing, for seismic isolation of buildings, bridges and other structures, including linear natural rubber bearing (LNR), lead rubber bearing (LRB) and high damping rubber bearings (HDR) 3.10 normal rubber bearing

Contents of GB 20688.3-2006

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Symbols 5 Classification 5.1 General 5.2 Classification by construction 5.3 Classification by ultimate properties 5.4 Classification by tolerance on shear properties 6 Requirements 6.1 General 6.2 Design compressive stress and design shear strain of isolators 6.3 Properties of isolators 6.4 Properties of rubber materials 6.5 Dimension of isolators 6.6 Strength of steel plates 6.7 Appearance 7 Design rules 7.1 General 7.2 Shape factor of isolator 7.3 Compressive and shear properties of isolators 7.4 Ultimate properties of isolator 7.5 Reinforcing steel plate design 7.6 Connection design 8 Tolerance 8.1 General 8.2 Tolerance of plane dimension of elastomeric isolator 8.3 Tolerance of height of elastomeric isolator 8.4 Tolerance of flatness of elastomeric isolator 8.5 Tolerance of horizontal offset of elastomeric isolator 8.6 Tolerance of plane dimension of flange 8.7 Tolerance of flange thickness 8.8 Tolerance on positions of flange bolt hole 9 Inspection rules 9.1 Inspection classification 9.2 Inspection items 9.3 Judgment rules 10 Marking and labelling of isolator 10.1 Information to be provided 10.2 Requirements 10.3 Examples Annex A (Informative) Technical deviations between this part and ISO 22762-3:2005 Annex B (Informative) Physical properties requirements of rubber materials Annex C (Informative) Determination of compression properties of rubber bearings Annex D (Informative) Determination of shear properties of bearings Annex E (Informative) Test determination of isolator ultimate properties Annex F (Informative) Test determination of buckling stability of isolators under large shear strain Annex G (Informative) Design methods for connecting bolts and flanges