GT-LS Cable Steel Seismic Bearing

GT-LS cable steel seismic bearing is an innovative and patented product for seismic isolators. All our conventional bridge bearing, such as spherical bearing, pot bearing and laminated bearing, can be equipped with steel cable to against seismic effects. GT-LS cable steel seismic bearings are designed with a principle “Force-movement balance”, specifically to dissipate energy by breaking-away the pre-established force threshold sacrificial restrainer and sliding between the sliding material and stainless steel, and to prevent collapse of bridge deck by the pre-established movement threshold steel cable.

Design features:

1) Free bearing can be realized without shear pin;

2) LS bearing plays a role as conventional pot/spherical bearing under normal condition;

3) Under extreme condition such as severe earthquakes, the shear pin will be broken away and all bearings work as free bearing to resist the earthquake forces and dissipate energy by friction;

4) The wire ropes by this point will greatly strengthen the bearing to avoid components falling off. This will allow the bearings to functional a reasonably longer time span during which the friction between PTFE plate and stainless steel plate can better consume the energy resulting from the earthquake;

5) The wire ropes are also able to restrict the bearing to move in a limited distance. By this the protection on the whole structure under earthquakes can be realized;

6) Over 10% costing effective under equivalent seismic requirement;

7) Loading capacity design ranges: 1,000 kN through 60,000 kN.

Calculation for length of cable:

LXY is the projection length of cable on the horizontal plan.

H is the height of the bearing.

AB are the length and width of the top plate, respectively

CD are the length and width of the bottom plate, respectively

δxδy are the longitudinal and transverse design displacement, respectively.

Calculation for Cable Stiffness:

As per mechanics of materials, stiffness K2 is calculated as follows:

E is the elasticity modulus of the cable; A is its cross-sectional area; L is the length.

The Vertical Limit Strength:

The ideal condition of the cable performing seismic reduction is under vertical limits strength of 30% to 50% of the bearing’s design load capacity.