Seismic ball bearings are interchangeable parts of the bridge, especially rubber bearings, due to material aging of its life than concrete, steel short, in addition to find fault and damage repair and replacement in a timely manner, the establishment of regular replacement of the system, namely the provisions should be mandatory life of the bearings to replace the lost, this is the road management system. Especially felt in the past, the use of oil, the pin bridge for easy seat, or other use of the bad effects of Bearings, in the conservation of replacement, should be replaced by other reliable bearing performance is essential. Maintenance and replacement of bridge bearings conditions based "highway bridge conservation norms" (JTG H11-2004) provides for the maintenance and replacement of bridge bearings conditions, the general methods and requirements as follows: 1. If the defect or seismic spherical bearings When failure is not working properly, should be amended and replaced. 2. seismic anchors spherical steel bearing pins cut, the rolling surface is not flat, bearing cracks or cuts, the right size rollers, concrete columns placed severe cracking, skew, it must be replaced. 3. Seismic spherical bearing steel base plate tilt, deformation, fracture and should be replaced, weld cracking should be trimmed. 4. Void appear laminated rubber bearing or uneven compression should be adjusted. 5. laminated rubber bearing large shear deformation occurred in the middle of plate exposure, rubber cracking, aging should be replaced. When loss of function, should be replaced 6. linoleum seat cushion. 

keywords: Ball bearings, seismic ball bearings, spherical bearings unidirectional earthquake,