[Grid] usual truss bearing support can be divided into peripheral support, the support point and point-supported mixing with the surrounding support three ways, surrounding the support is resting on the grid nodes surrounding the beam or column, point support is The grid spacing greater seat rests on independent beams or columns, pillars and other structures without contact. When the grid (net shell) resting on beams or columns, beams and vertical stiffness can be considered a great column, ignoring the vertical beams and pillars axial strain deformation, so the grid (net shell) bearing vertical displacement is zero , the grid (net shell) bearing horizontal deformation substructure should consider working together. [Seat] grid in the surrounding supporting grid (net shell) radial bearing structure should lower support grid as an elastic constraint (net shell) structure, and point of support grid (net shell) bearing border Conditions should consider the level of the X and Y directions of the elastic constraints. Equivalent spring stiffness of the support structure calculation are the following: 1) the equivalent spring stiffness supporting pillar supporting 承柱子 horizontal displacement direction is: Kc = 3EcIc / H3c where Hc: high column; Ic: Column sectional moment of inertia. [Grid] abutment ends simply supported beam supported by a length L, grid beam end bearing located at a distance equivalent to a simply supported beam spring stiffness is: Kb = 3EbIbL / a2 (La) 2 where a : The role of pitch beam end distance; L: length of the beam; Ib: Beam moment of inertia. Rubber advances from the height of the rubber seat pad support abutment Hp equivalent spring stiffness is: Kp = GpAp / Hp where Ap: rubber mat area; Hp: rubber booster. Ball bearings have lower support intaglio, ball cap liner, bearing slide on Teflon sliders (each a plane and spherical, hereinafter referred to as PTFE sheet) and rubber seals and dust cover and other components. Ball cap liner is ball bearing core, it opened flat portion inlaid PTFE plate recess seismic slip grid support forum for fixing flat PTFE plate. Spherical radius of the spherical portion must ensure compliance with the design requirements and sr, usually 0.3% steradian spherical PTFE plate diameter. Spherical work surface plated with chromium layer having a thickness of about 80 ~ 100μm. Spherical machining accuracy will directly affect the performance of bearing rotation. Corner seat by sliding the ball cap liner and spherical PTFE plate quality control to achieve. Ball cap liners typically steel or ZG270-500 made available. Intaglio from steel plate under the seat or seat bearing slip casting composition flexible, mainly from the effect of fixing the spherical PTFE plate sliding bearings and bearing reaction force is transmitted to the pier dispersed, the bridge table. Flat PTFE plate and the main spherical sliding member tetrafluoroethylene plate bearing in PTFE sheet surface with special abrasive oil storage pits pressed into grease and coated with silicone grease 5201 to reduce sliding friction PTFE sheet and wear. Sliding surface PTFE plate and stainless steel plate on the bearing plate quality control can meet the needs bearing displacement, it works with rubber bearing basin complete agreement. The bearing plate with ordinary steel or cast steel, the bearing plate and tetrafluoroethylene plate sliding contact surface of the spring plate holder, with the TIG welding finishing a 1Cr18Ni9Ti stainless steel plate, stainless steel plate surface and requested PTFE sheet flatness is not more than 0.3% of the diameter, to ensure that the coefficient of friction bearing no more than 0.03.