TDP is a double spherical surface friction pendulum type earthquake isolator device developed by TİS. TDP consists of two sliding elements located between the support plate with the same radius of curvature. The lower and upper surfaces of the sliding element have the same properties and the radius of curvature is compatible with the support plates. In this way, the parallelism of the parts above and below the isolator plane of the building is maintained during the earthquake action.
In TDP, movement takes place simultaneously on both surfaces where the sliding element and support plates come into contact with each other. During an earthquake, two different materials on these surfaces move on each other to meet the need for horizontal displacement and energy absorption is achieved through the resulting friction. The materials on the friction surfaces are bright stainless steel sheet on the backing plate side, and Technoslide®, a patented special friction material developed by TİS on the sliding element side.
For more information about TDP, you can reach our catalog HERE.
TSP is a single spherical surface friction pendulum type earthquake isolator device developed by TİS. TSP consists of two sliding elements located between the support plate with different radius of curvature. The upper and lower surfaces of the sliding member have the radii of curvature of the support plates with which they are matched.
In TSP, one surface of the sliding element is located on the steel support plate and meets the horizontal displacement demand. This surface also determines the oscillation period. The other surface is placed on the other support plate in a way that prevents horizontal movement and only provides rotation. During horizontal movement, the parallelism between the substructure and superstructure can also be maintained in this way.
For more information on TSP, you can find our catalog HERE.
TİS Pot Bearing (TPB) device is the pot bearing type used in structures to connect the different building elements (superstructure and substructure) produced by TİS Technological Isolator Systems A.Ş. The working principle of TPB bearings is basically to transmit the forces generated in the superstructure to the substructure at the desired rate and to allow the rotations created by the effects of the superstructure and other movement demands that the basic effects listed below will create.
- Shrinkage and expansion in concrete
- Seismic effects
- Temperature changes
TPB bearings are designed in accordance with the conditions specified in all relevant parts of TS EN 1337, especially TS EN 1337-2 and TS EN 1337-5.
TPB bearings are produced in 3 different types according to these force and displacement interactions that need to be regulated. Bowl bearings produced by TIS A.Ş. are listed below.
- Fixed bearing: TPB-FX
- Free sliding pot bearing: TPB-FS
- Guided sliding pot bearing: TPB-GS
TPB-FX TBP-FX consists of a rubber pad inside a pot-shaped steel element and a steel piston that presses on the rubber pad and provides rotational motion. This type of bearings counteract horizontal displacement demands in all directions and allow the superstructure to rotate only around any horizontal axis. Since the rubber pad in the pot is restricted from all sides, it acts as an incompressible fluid under very high vertical loads and creates high resistance against the pressure created by this vertical load and allows the piston to rotate with the shear deformation in the rubber. In addition, it transmits the horizontal forces existing in the superstructure and transferred to the piston connected to it, to the pot and thus to the substructure through the piston-pot wall contact.
TPB-FS is created by placing a plate on a TPB-FX type support that can slide in any direction in the horizontal direction. This surface consists of a dimpled PTFE plate fixed on the piston and a sliding plate on this PTFE plate, on which is placed polished stainless steel on its bottom surface. This sliding surface allows the upper structure to move in all horizontal directions relative to the substructure, with the low friction contributed by the oil contained in the pits of the PTFE plate. In addition, it does not transfer the horizontal forces existing in the superstructure to the infrastructure.
TPB-GS is almost the same as a TPB-FS type bearing, but this type of bearing has a guide placed in one direction in the middle of the PTFE-inserted piston top surface. In addition, there is a recess in the sliding top plate where the guide will be placed. The guide ensures that the upper plate moves only in the direction of design displacement and prevents the movement in all other directions and transmits the horizontal force generated in those directions to the lower parts and the substructure through the upper plate-guide contact.
- 1. Pot
- 2.Rubber cushion and inner gasket
- 3. Piston
- 4. PTFE
- 5. Slide
- 6.CM1 Composite material
- 7.Top plate
- 8.Stainless steel
- 9. Anchor bolts
- 10. Protection system against dust
Cup, piston, guide and top plates of TPB bearing are produced from S355 structural steel. Since S355 steel is a material whose properties are well known, it provides convenience in both design and processing processes. In addition, S355 structural steel has proven its strength with its performance under various structural loads.
The rubber cushion inside the pot, with a compressive strength of 60 MPa and a minimum Shore A50 hardness, ensures that the vertical force is transmitted to the substructure without damaging the bearing, and provides resistance to rotational movements without damage during its use.
High quality POM or carbon filled PTFE gasket is used to prevent the pad from coming out of the pot during the rotational movements of the piston on the rubber pad or to prevent it from being damaged during the compression-opening movement.
In guided or free sliding bearings, grooved PTFE and lubricant oil with a pressure resistance of at least 90 MPa are used, these materials provide both high vertical pressure resistance and a low friction coefficient sliding surface.
In guided sliding bearings, composite materials with a compressive strength of at least 200 MPa and a low friction coefficient are used to provide a sliding surface on the side surfaces of the guide and to withstand horizontal loads transferred from the top plate to the guide.
For more information about bearings, you can find our catalog HERE.
Buckling Restrained Brace (BRB) is a Steel-Yielding damper system invented to modify performance of steel braces. Unlike many types of seismic dampers, which include materials unfamiliar to civil engineers, the main element in BRB is structural steel. As a result, the BRB has predictable behavior and much longer lifetime than other types of dampers.
The compressive and tensile performance of BRB in cyclic loading is equal and stable. Due to its flexibility, this system plays the role of fuse in the structure, concentrates the damages, and dissipates the earthquake energy. This significantly increases the safety of the structure and reduces damage to the main elements such as beams and columns that carry the weight of the building.
Minimum Provisions and Acceptable Structural Performance
Many people think that structures designed according to minimum provisions are safe from earthquake damages; but in fact, the earthquake codes in each country set minimum requirements that must be applied to every structure according to the general economic situation of that country. In the case of earthquakes, these criteria are only for life safety and are not a guarantee for saving the capital and the serviceability of buildings. In other words, using conventional methods in the construction of structures and applying the minimum provisions, it only protects the building from collapse, and in this case, significant damage to the structure and contents of the building is inevitable.
Due to the high ductility of the inner core of the BRB, due to cyclic loads of the earthquake, a significant amount of seismic energy will be reduced due to the yield behavior and hysterical cycles created in BRB, results in mitigation of the earthquake effects on the building.
Advantages of BRB
The advantages of using BRBs are as follows:
- Increase the flexibility and reliability of the structure against earthquakes.
- Decrease the weight of structural elements, connections, and foundation.
- No damage to non-structural walls during the earthquake due to elimination of buckling.
- Prefabricated, easy and fast installation, thus reducing project running time.
- Possibility of installation in all types of reinforced concrete and steel structures, without any restrictions on the length of the brace.
- Capability to change and adjust the stiffness and strength of the brace separately.
- Easy to model in engineering software and design with linear analysis.
- No need to replacement after minor and moderate earthquakes.
- Replaceable after major earthquakes at a low cost.
- Invulnerable to environmental conditions
Usability in many structural systems
BRBs are very adaptable and can be used in all kinds of structures including Steel, concrete, composite as well as structural systems including frames, dual systems including moment frames etc.
Move to higher safety levels.
For more than two decades, in seismic countries such as Japan, the seismic design approach has shifted from increasing the strength of structures to controlling and dissipating earthquake vibrations. These new methods, which have repeatedly shown their reliability in large earthquakes, include the use of dampers that dissipate the main part of earthquake energy by being placed in the structure, and therefore they will save the main elements of the structure, namely beams and columns from damages. In the other words, these elements will act as a fuse. Among different types of damping methods, the use of Buckling Restrained Braces (BRB) technology is the most efficient, common, and economical way to achieve this goal.
BRB, A System with Two Main Role
BRBs can well play both roles of brace and damper in the structure. Accordingly, there are two approaches to using this technology: in Japan, for example, this element is considered and used as a Metallic Damper; but in the United States, they are considered as a structural system and a modified brace. Both approaches have led to widespread use of this technology.
BRBs can be used as a lateral system because of their good stiffness against lateral forces like earthquakes. This advantage makes BRB one of the few dampers that can be used alone in a frame.
It can be used in all structures in which it is possible to install a brace. Due to the variety in how BRB is connected to the structure, it is possible to use it in new buildings or reinforcement of all industrial structures, bridges and steel or reinforced concrete buildings.
High ductility and reliability of BRB have led to definition of any required provisions and coefficients for its design and applications, in international codes. The use of BRB in new constructions will result in less structural weight and increasing the safety of structure against earthquakes.
Since in retrofit projects, in many cases we are dealing with a building that is in use, the application of a method that has the least construction operations and the most efficiency is a priority. In addition to the above, the use of BRB will speed up the operation and will be more economical than many other retrofitting methods. So far, many projects have been rehabilitated with BRB with minimal disruption to serviceability.
A Ductile System
International codes introduce BRB as a flexible system. ASCE7-16 sets a Response Modification Coefficient as 8 for it. This high Response Modification Coefficient reduces the base shear, results in less structural weight and usage of materials and saves costs.
Adjust the optimal strength and stiffness.
One of the unique features of BRB is the capability to adjust the strength and stiffness separately in the specific spans; In such a way that the braces can be designed in a way that the strength increases in the specific spans according to the needs of the structure, but the stiffness remains low, high or unchanged, and vice versa.