Introduction of GPZ Pot Rubber Bearing
Structure and function of the pot rubber bearing
The pot rubber bearing uses the elastic rubber block in the semi-closed steel pelvis to realize the rotation of the upper structure under the state of three-way force. At the same time, it relies on the low friction coefficient between the polytetrafluoroethylene plate on the middle steel plate and the stainless steel plate on the upper seat plate to realize the horizontal displacement of the upper structure.
From the experimental data, the compressive elastic modulus of the rubber in the three-way restraint state is 5*104kg/cm2, which is nearly 20 times larger than that without lateral restraint, so the bearing capacity is greatly improved which solves the limitation of ordinary rubber bearings. Therefore, the pot rubber bearing is a new type of product that can meet the requirements of large support reaction force, large horizontal displacement, and large corner angle.
Application of pot rubber bearing
The pot rubber bearing is suitable for long-span bridges and urban road bridges with a rubber bearing force of more than 50,000 kN.
Performance characteristics of pot rubber bearing
The pot rubber bearing is composed of upper bearing plate (including top plate and stainless steel sliding plate), PTFE sliding plate, middle steel plate, sealing ring, elastomeric pad, bottom steel plate, anchor bolts and so on. The one-way movable support has a guide block along the moving direction, and the fixed support does not have a PTFE slide plate or a stainless steel slide plate.
The plane sliding of the stainless steel plate and PTFE plate is used as the sliding surface of the support, with low friction coefficient, large bearing capacity, small vertical deformation, strong wear resistance and strong corrosion resistance. The structure of the support is simple, light in weight, and the price is lower than that of the cast steel support, which has obvious economic benefits. The building height is low, which is very beneficial to the structural design of the bridge, and it is easy to use and maintain.
Installation steps of pot rubber bearing
- Support pad stones should be set under the pot bearings, and the concrete strength grade of the support pad stones should not be lower than C40. The height of the plinth stone should consider the convenience of support installation, maintenance, and replacement. Local pressure-bearing parts require the configuration of the corresponding reinforcement mesh. Bolt holes shall be reserved on the top surface of the pier according to the specification and quantity of the anchor sleeve. The diameter and depth of the reserved bolt hole are 50mm~60mm larger than the diameter and length of the sleeve, and the center deviation should not exceed 10mm.
- After the bearing is transported to the site, the parts and packing list of each part of the bearing should be checked out of the box. After passing the inspection, put it into the packing box again, and then unpack it when installing.
- The movable bearing should pay attention to the protection of the polytetrafluoroethylene plate and the stainless steel cold-rolled steel plate after unpacking to prevent scratches or dirt on the surface of the vinyl plate and cold-rolled steel plate, and check whether the 5201-2 silicone grease is filled fully.
- When the bearing is installed, the top surface of the supporting pad stone should be roughened, and the sundries on the pad stone should be washed away with clean water. After the surface of the pad stone is dry, apply an epoxy mortar leveling layer on the top surface of the pad stone other than the position of the anchor bolt hole. After the bearing is centered and leveled, use spacers to pad the bearing, and use epoxy mortar or mortar with a higher strength grade to fill the gap around the sleeve and the position around the bottom plate of the bearing that is not filled with epoxy mortar. After the completion of the work, the overflowing mortar outside the bottom plate of the bearing should be cleaned up, and the spacers should be removed after the mortar hardens.
- When installing two-way and one-way movable bearings, special attention should be paid to checking the polytetrafluoroethylene plate. The main sliding direction of the polytetrafluoroethylene plate should be consistent with the direction of the bridge.
- After the installation is completed and passed the inspection, remove the connecting components and install the dustproof enclosure.