Technical field of the invention

The present invention relates to a structural seismic isolation system (SSIS) that is obtained through structural seismic isolation method (SSIM) presented to ensure that the structure is not affected by resonation caused by the effects of the long-term components of the ground motion-earthquake, and that the base moment of the building is less than that of the structure obtained by conventional seismic isolation methods (CSIM) due to the impact of the strong ground motion-earthquake.

The present invention particularly relates to a structural seismic isolation system (SSIS) that is obtained through structural seismic isolation method (SSIM) and in which the basic contact surface exhibiting inverted pendulum behavior has various curvilinear (spherical, elliptical, etc.) surfaces depending on earthquake, ground, superstructure parameters, and in which the lower part of the superstructure is also a curvilinear surface in accordance with this basic contact surface and these curvilinear structure- based contact surfaces are equipped with Seismic Isolation Elements (SIE).

The State of the Art

Today, the living spaces are becoming narrower and the number of buildings in living spaces is increasing accordingly due to the increasing population. Due to this increase, it can be seen that especially living spaces, in other words buildings, have towered. In such case, the strength of a structure is crucial. These buildings must have strength especially against natural disasters such as earthquakes and storms. The high-security structures that mainly will be situated in World’s I. and II. earthquake and storm zones must be protected from the effects of strong and long-term ground motion-earthquake or storm and strategically it has a greater importance, wherein said buildings are classified as follows: High-rise Structures, high-rise structures having properties such as information, operating systems, precision devices, communication systems, routing systems, bank operating systems, databases, management systems, etc. related to the security and economy of a country therein, high-rise hospitals, reactor structures of Nuclear power plants, oil-gas base platforms, television tower and similar structures. There are some methods that are used for increasing the strength of structures. The methods, which are used especially against earthquake, are Retrofitting Methods for Conventional Seismic Properties (RMCSP) and Conventional Seismic Isolation Methods (CSIM). Retrofitting Methods for Conventional Seismic Properties (RMCSP) comprises reduction of the building mass by using lightweight materials, keeping the floor mass and stiffness centers as close to each other as possible, adjusting the properties of the structure such as seismic load carrying capacity, stiffness, ductility, stability, inelastic deformations in accordance with achieving the building performance targets.

Conventional Seismic Isolation Methods (CSIM) aim to reduce the stiffness of the structure, increase its period and absorption, and to bring smaller earthquake forces to the structure by taking into account the characteristics of the structure and the earthquake acceleration. In accordance with these objects, Seismic Isolation Elements (SIE) are used between the plane foundation surface and the plane superstructure base in Conventional Seismic Isolation Method (CSIM) applications. Said Seismic Isolation Elements (SIE) comprises laminated rubber bearing (LRB), lead core laminated rubber bearing (LCLRB), seismic base insulation based on the friction-based pendulum principle (SBIFPP), dampers, active control elements etc.

The Conventional Seismic Isolation Methods (CSIM) provides further and more reliable opportunities for the design and development of earthquake resistant structures in parallel with the Retrofitting Methods for Conventional Seismic Properties (RMCSP).

With the Conventional Seismic Isolation Methods (CSIM) in the state of the art, there are some developments made for reducing the possibility of resonance of the structure, the fatigue-fracture possibility of Seismic Isolation Elements (SIE) and the earthquake effect.

As a result of the preliminary research about the state of the art, the patent documents numbered US20060260222A1 , US5979127A, US4881350A, US20170108034A1 , US20090188179A1 , US20170342734A1 have drawn attention among patent documents that have been analyzed. In these patent documents, it is intended to reduce the effect of earthquake through structural support type elements, which are given the opportunity to rotate with the frictional interface. These studies can be roughly generalized as a seismic base isolation support-element based on the Friction Pendulum Bearing Base Isolation principle in the type of patent document numbered US20090188179A1. Since this seismic base isolation element carries the building load to the small area pendulum support on the friction surface, said support cannot function immediately by creating permanent deformation on the friction surface of the element during the waiting period until the destructive earthquake occurs and by seizing up during the earthquake. In the structures with higher loads, the plate under the pendulum support has a high risk of tearing. Due to these deficiencies, their applications are limited.

As a result of the preliminary research about the state of the art, the patent document numbered “CN205077505” is analyzed. In the invention of the application discloses an earthquake-resistant building with an impact resistant structure that includes a foundation and a floor on the foundation along the vertical direction cross-sectional area. This inventive building is placed above the ground in one of the seismic structures that contain a foundation and is located above the ground, and the foundation gradually decreases in cross-sectional area from top to bottom in a vertical direction. Also, the base part has a spring structure in a vertical direction.

As a result of the other preliminary research about the state of the art, the patent documents numbered CN205152779U, CN106930311A, CN107514175A,

CN207228740U, US20180195267A1 , US20140026498A1 have drawn attention among patent documents that have been analyzed. However, in all these patents, a frictional interface is used between said superstructure and curvilinear foundation of building. Therefore, it is aimed to keep the structure under control from earthquake effects within safe limits only with the friction coefficient of the friction interface. Today, for the existing building mass, huge superstructure-foundation area and existing friction interface materials, it is known that keeping the structure under reliable limits with only the friction coefficient from the earthquake effect is theoretically and practically not a subject of solution.

In the light of other preliminary research about the state of the art, the vibration period of the seismic base isolation elements such as Laminated Rubber Bearing (LRB) and Lead Core Laminated Rubber Bearing (LCLRB) is between 2-4 seconds. The predominant period is shifted to the 2-4 seconds interval by adding said types of seismic base isolation elements to structures and by this way the earthquake effect is mitigated. However, these structures remain unprotected by resonating in case of effects of long (greater than 4 seconds) period components of ground motion. Today, this problem cannot be solved completely by using the Seismic Isolation Elements (SIE) in a Conventional Seismic Isolation Methods (CSIM).

Consequently, the existence of aforementioned disadvantages and insufficiency of current solutions necessitated making an improvement in the technical field.

Objects of the Invention

The main object of the invention is to ensure that the structure does not resonate and besides, to ensure that the base moment of the structure is reduced compared to the CSIM method. The current structure is converted into a Structural Seismic Isolation System (SSIS), which exhibits inverted pendulum behavior, by means of the presented Structural Seismic Isolation Method (SSIM). Therefore, the structure base and basic contact surfaces are made of various curvilinear (spherical, elliptical, etc.) surfaces depending on the earthquake, ground, superstructure parameters and these contact surfaces are connected to each other by Seismic Isolation Elements (SIE).

Another object of the invention is to ensure that various Seismic Isolation Elements (SIE) are used in order to control the system’s response.

Another object of the invention is to ensure that dominant period of the Structural Seismic Isolation System (SSIS) can be set above the long period formed by ground motion-eartquake. In addition to this feature that the base insulation elements mentioned above do not resonate differently from the structures applied with conventional method (CSIM), it causes the cross-sections of the structural elements to decrease, the building mass to decrease, and the column openings and structure height to increase in proportion to the decrease of the building base moment.

Another object of the invention is that Structural Seismic Isolation System (SSIS), which exhibits “Bobo Doll” behavior, is more safe and economical by being affected less by an average of 33% earthquakes than the structure which is Conventional Seismic Isolation Methods (CSIM).

Another object of the invention is to ensure that laminated rubber bearing (LRB), lead core laminated rubber bearing (LCLRB), seismic base insulation based on the friction- based pendulum principle (SBIFPP) type Seismic Isolation Elements (SIE), which are currently manufactured, are used efficiently and applied thanks to Structural Seismic Isolation Method (SSIM).

The structural and characteristic features of the invention and all the advantages thereof will be more clearly understood by means of the accompanying figures and the detailed description provided by making references to those figures. Therefore, the evaluation should be conducted by taking said figures and the detailed description into the consideration.

Detailed Description of the Figures

Figure 1 illustrates the perspective view of the system subjected to the invention. Figure 2 illustrates the exploded view of the system subjected to the invention.

Figure 3 illustrates the schematic view of the conventional use method of the Seismic Isolation Elements (ISE).

Description of the Reference Numerals

1. Superstructure 2. Curvilinear Surfaced Base of Superstructure

2b. Plane Surfaced Base

3. Seismic Isolation Elements (SIE)

4. Curvilinear Surfaced Foundation

4b. Plane Surfaced Foundation 5. Intersection plane of superstructure and superstructure base

Detailed Description of the Invention The present invention is a Structural Seismic Isolation System (SSIS) that is presented to protect structures from the effects of strong and long-period ground motions- earthquakes or storms.

The inventive Structural Seismic Isolation System (SSIS) generally consists of a superstructure (1) and curvilinear surfaced foundation (4). The superstructure (1) can be highly reliable structures that may be situated in World’s I. and II. level earthquake or storm zones. These structures are high-rise Structures, high-rise structures having properties such as information, operating systems, precision devices, communication systems, routing systems, bank operating systems, databases, management systems, etc. related to the security and economy of a country therein, high-rise hospitals, reactor structures of Nuclear power plants (nuclear containment structures), oil-gas base platforms, television tower and similar structures.

Seismic Isolation Elements (SIE) (3) are located between the curvilinear surfaced base (2) of the superstructure and the curvilinear surfaced foundation (4), prevent structure from resonating and ensure that the sections of structure bearer elements become smaller as the moment on superstructure and intersection plane of superstructure (5).

The curvilinear surfaced foundation (4) is the element that safely transfers the loads of the superstructure (1) on which the superstructure (1) will be located.

Figure 1 illustrates the completed structure. Figure 2 illustrate the details of the application of Structural Seismic Isolation System (SSIS). In the base part of the superstructure (1), there is curvilinear surfaced base of superstructure (2). The curvilinear surfaced base of superstructure (2) has a geometrical compatibility with the curvilinear surfaced foundation (4). The surface shapes and forms of curvilinear surfaced base of superstructure (2) and curvilinear surfaced foundation (4) are obtained in accordance with the parameters of earthquake, ground and superstructure, wherein these surfaces can be spherical, elliptical and etc. There are Seismic Isolation Elements (SIE) (3) between the curvilinear surfaced base of superstructure (2) and the curvilinear surfaced foundation (4).

Seismic Isolation Elements (SIE) (3) that are positioned between the curvilinear surfaced base of superstructure (2) and the curvilinear surfaced foundation (4) ensures that the structure does not resonate and sections of the structure bearer elements become smaller as the structure base moment reduces, the structure mass is reduced, and the spacing between structural columns and structure height is increased.

The Structural Seismic Isolation System (SSIS) subjected to the present invention, which exhibits “Bobo Doll” behavior and uses the plane surfaced foundation (4b) and the plane surfaced base (2b) that are used with the conventional method and shown in Figure-3., can be more safe and economical by being affected less by an average of 33% earthquakes than the structure which is Conventional Seismic Isolated Method (CSIM).

By means of the inventive Structural Seismic Isolation System (SSIS), it is ensured that the superstructure (1 ) does not resonate due to the effects of long-term components of ground motion, earthquakes or storms. Similarly, it is ensured that the structure base moment is low from the effect of strong ground motions, earthquakes or storms compared to the structure which is seismically isolated with the conventional method that is found in the state of the art.

By obtaining the precise geometry of the curvilinear surfaced base of superstructure (2) depending on the earthquake, ground, and superstructure parameters, it may be spherical, elliptical and similar curvilinear surfaces.