Hao-engineering rubber, seismic activity ball bearing, ball bearing activities provided by Hao-engineering rubber. We are Hengshui HaoTong Engineering Rubber Co., Ltd. (www.htgcxj.com) located at: Hebei Hengshui specializes in: grid bearings, bridge expansion joints, water stop, bridge bearings, rubber bearings, spherical steel bearing foreign countries have widely used in more than 4,000 bridges, and in the 1970s and 1980s, have been a complete standard specification, confirmed the laminated rubber bearing works bi-directional ball bearing activities, design methods, machining tolerances and finished products mechanical testing requirements, such as the International Union of Railways UIC regulations published in 1969, the German "structures bearing" (DIN 4141-1981), British Standard "Steel, concrete and composite bridges Bridge" (BS5400-1978) in ninth articles "bridge support" the United States' highway bridges standards "(AASHTO-1983) in the low 14 Chapter 25 Chapter elastic support as well as France, India and other countries also have their own standards do too. 1956 Development of laminated rubber bearings and published the "Handbook roads and bridges support" grid activities ball bearings, in the 1982 amendments expanded the scope of use of laminated rubber bearings. With the advancement of technology, perfect testing means testing and practical application of these standards are constantly revised and improved, such as the United States published in the "American Highway Bridge Design Specifications" (AASH-TO-LRFD) version of the 2004 Chapter 14 of the seams and bearing, DIN and British BS5400 and European standards are published EN1337-2005 corresponding structures bearing, Japan once again revised the publication of "Handbook road bridge support," 2004 and so on. However, these standards revision of laminated rubber bearing works finds no substantial change in type, as the American bridge design specifications noted, some changes in the form of some formula, single physical meaning has not changed. Rotational displacement for the upper structure of the resulting deflection. Produce a corresponding bump in the free side of the laminated rubber bearing rubber bearings to withstand external force shown below, at any point on the seat, by the impact of the design load effect laminated rubber bearings and reliable performance ball bearing activities, with good elastic properties, can reduce the dynamic load on the bridge piers across the structure and role of the impact of the earthquake activity ball bearing, thus improving the overall force and bridge seismic performance. Low height laminated rubber bearing construction (eg for steel bearing on the general height of small span bridges 90 ~ 180mm, while the corresponding laminated rubber bearing construction height of only 28 ~ 56mm), easy construction and installation and replacement. Damping rubber bearings bearing than usual to reduce the power generated by the seismic displacement beam level, so from driving and seismic point of view, I hope to be studied in the future as far as possible from multi-span continuous development direction.