Open caisson foundation with shock absorption and isolation functions

Abstract

The application discloses a caisson foundation with shock absorption and isolation functions, and relates to the technical field of bridge construction.The caisson foundation with shock absorption and isolation functions comprises a caisson lower step, a caisson upper step, a plurality of first shock absorption and isolation devices, a plurality of second shock absorption and isolation devices and a sealing protective layer.The caisson lower step is provided with a ring of corbels at the top thereof.The bottom end of the caisson upper step is arranged on the top of the caisson lower step and within the ring of the corbels.The sealing protective layer is arranged between the caisson lower step and the caisson upper step to form a protection chamber, and the first shock absorption and isolation devices and the second shock absorption and isolation devices are arranged in the protection chamber.The first shock absorption and isolation devices and the second shock absorption and isolation devices are arranged to effectively buffer the action force of strong earthquakes, and the protection chamber is arranged to effectively prevent the first shock absorption and isolation devices and the second shock absorption and isolation devices from contacting the external environment, thereby prolonging the service life of the caisson foundation with shock absorption and isolation functions.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, specifically to a caisson foundation with seismic isolation and damping functions. Background Technology

[0002] Currently, with the rapid development of long-span bridges, especially cross-sea bridges, caisson foundations are accounting for an increasingly large proportion of bridge foundations, despite their superior mechanical properties. However, under strong earthquakes, caisson foundations can still displace, leading to damage to the superstructure. Existing engineering practices lack solutions to address caisson foundation displacement and superstructure damage under strong earthquakes. Scientific research has only explored the use of buffer zones between the foundation and the ground, employing layers of crushed stone or seismic isolation devices to buffer the impact of strong earthquakes. However, once the foundation displaces, it is difficult to restore it to its original position. Furthermore, long-span bridges are typically built on rivers, lakes, or seas, placing the foundations in highly corrosive environments. The buffer structures added by the separated design are susceptible to seawater erosion, affecting the bridge's service life. Summary of the Invention

[0003] This invention provides a caisson foundation with seismic isolation function, which can solve the problems of caisson foundation displacement and superstructure damage under strong earthquakes, while avoiding the problem of caisson foundation being easily corroded in seawater.

[0004] This invention provides a caisson foundation with seismic isolation function, comprising:

[0005] The steps leading down the caisson are topped with a ring of corbels around the outer edge.

[0006] The bottom of the upper step of the caisson is placed at the top of the lower step of the caisson and is located within a circle of corbels. The upper step of the caisson can move relative to the lower step of the caisson.

[0007] Multiple first vibration damping and isolation devices are installed between the corbel and the upper step of the caisson;

[0008] Multiple second vibration damping and isolation devices are installed between the lower step of the caisson and the upper step of the caisson;

[0009] A sealing protective layer is disposed between the lower step and the upper step of the caisson, and forms a protective chamber with the lower step and the upper step of the caisson. A plurality of first vibration damping and isolation devices and second vibration damping and isolation devices are disposed in the protective chamber.

[0010] In one implementation:

[0011] The steps leading up to the caisson include a first outer wall surrounding the caisson and a first inner wall arranged in a crisscross pattern within the first outer wall.

[0012] Multiple second vibration damping and isolation devices are respectively installed at the connection between the first outer wall and the first inner wall and at the intersection of the first inner wall.

[0013] In one implementation:

[0014] The sealing protective layer includes:

[0015] The first protective layer is located between the corbel of the lower step of the caisson and the first outer wall;

[0016] The second protective layer is located between the top of the lower step of the caisson and the first outer wall;

[0017] The protective chamber includes a first chamber;

[0018] The first protective layer and the second protective layer, together with the corbel of the lower step of the caisson and the upper step of the caisson, form the first chamber.

[0019] Multiple first vibration damping and isolation devices and multiple second vibration damping and isolation devices located at the first outer wall are sealed in the first chamber.

[0020] In one implementation:

[0021] The sealing protective layer also includes:

[0022] The third protective layer is located between the top of the lower step of the caisson and the intersection of the first inner wall;

[0023] The protective chamber also includes a second chamber;

[0024] The third protective layer, together with the upper and lower steps of the caisson, forms multiple second chambers;

[0025] Multiple second vibration damping and isolation devices located at the intersection of the first inner walls are respectively sealed in multiple second chambers.

[0026] In one implementation:

[0027] The first and second chambers are filled with liquid grease.

[0028] In one embodiment, the first vibration damping and isolation device includes:

[0029] A spring, which is arranged parallel to the top of the lower step of the caisson;

[0030] The viscous damper is arranged parallel to the top of the lower step of the caisson.

[0031] In one implementation:

[0032] The caisson lower steps include a second outer wall around the perimeter and a second inner wall arranged in a crisscross pattern within the second outer wall;

[0033] The second inner wall of the lower step of the caisson is provided in correspondence with the first inner wall of the upper step of the caisson.

[0034] In one implementation:

[0035] The second inner wall is thicker than the first inner wall, and the second outer wall is thicker than the first outer wall.

[0036] In one implementation, it further includes:

[0037] The bottom sealing concrete is placed at the bottom end of the lower step of the caisson.

[0038] In one implementation:

[0039] The second vibration damping and isolation device is a friction pendulum vibration damping and isolation support.

[0040] This invention discloses a caisson foundation with seismic isolation function. The caisson foundation includes: a lower caisson step with a ring of corbels around its top perimeter; an upper caisson step, the bottom of which is positioned at the top of the lower caisson step and within the ring of corbels, the upper caisson step being movable relative to the lower caisson step; multiple first seismic isolation devices disposed between the corbels and the upper caisson step; multiple second seismic isolation devices disposed between the lower and upper caisson steps; and a sealing protective layer disposed between the lower and upper caisson steps, forming a protective chamber with the lower and upper caisson steps, the multiple first and second seismic isolation devices being disposed within the protective chamber. This invention effectively buffers strong earthquake forces by setting up the first and second seismic isolation devices and the protective chamber, and the protective chamber effectively prevents the first and second seismic isolation devices from contacting the external environment, thus extending the service life of the caisson foundation. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a cross-sectional view of a caisson foundation with vibration reduction and isolation function according to an embodiment of the present invention;

[0043] Figure 2 This is a cross-sectional view of the upper steps of the caisson according to an embodiment of the present invention;

[0044] Figure 3 This is a cross-sectional view of the lower step of the caisson in an embodiment of the present invention.

[0045] In the diagram: 10. Upper step of the caisson; 11. First inner wall; 12. First outer wall; 20. Lower step of the caisson; 21. Second inner wall; 22. Second outer wall; 30. Corbel; 40. Second vibration damping and isolation device; 50. Sealing protective layer; 51. First protective layer; 52. Second protective layer; 53. Third protective layer; 60. First vibration damping and isolation device; 61. Spring; 62. Viscous damper; 70. Bottom sealing concrete; 80. Protective chamber; 81. First chamber; 82. Second chamber. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] With the rapid development of long-span bridges, especially cross-sea bridges, caisson foundations are accounting for an increasingly large proportion of bridge foundations. While caisson foundations possess good mechanical properties, they can still fail under strong earthquakes. Therefore, ensuring the safety of bridges using caisson foundations, especially long-span bridges, during earthquakes has become a widely concerned issue in the engineering community. However, current research on the seismic performance of bridge foundations mainly focuses on shallow foundations and pile foundations, while research on the seismic performance of caisson foundations lags behind, and a comprehensive theoretical system and design method for caisson foundation seismic resistance are lacking.

[0048] like Figure 1 As shown, this invention discloses a caisson foundation with vibration damping and isolation functions, characterized in that it includes: a lower caisson step 20, with a ring of corbels 30 arranged around its top periphery; an upper caisson step 10, the bottom of which is placed at the top of the lower caisson step 20 and located within the ring of corbels 30, the upper caisson step 10 being movable relative to the lower caisson step 20; a plurality of first vibration damping and isolation devices 60, which are disposed between the corbels 30 and the upper caisson step 10; a plurality of second vibration damping and isolation devices 40, which are disposed between the lower caisson step 20 and the upper caisson step 10; and a sealing protective layer 50, which is disposed between the lower caisson step 20 and the upper caisson step 10, and forms a protective chamber 80 with the lower caisson step 20 and the upper caisson step 10, the plurality of first vibration damping and isolation devices 60 and second vibration damping and isolation devices 40 being disposed in the protective chamber 80.

[0049] The caisson foundation with seismic isolation function includes two parts: an upper caisson step 10 and a lower caisson step 20. The upper caisson step 10 is located at the top of the lower caisson step 20, and the lower caisson step 20 supports the upper caisson step 10. A ring of corbels 30 is also provided at the top of the lower caisson step 20, and the corbels 30 are integral with the lower caisson step 20. The external dimensions of the upper caisson step 10 are smaller than the internal space enclosed by the corbels 30. The bottom of the upper caisson step 10 is placed at the top of the lower caisson step 20 and within the ring of corbels 30. Multiple second seismic isolation devices 40 are provided between the corbels 30 and the upper caisson step 10. These devices are evenly distributed between the corbels 30 and the upper caisson step 10, so that the multiple second seismic isolation devices 40 can provide support to the upper caisson step 10 from its four sides. When the upper step 10 of the caisson moves horizontally relative to the lower step 20, the compressed secondary vibration damping devices 40 provide support, allowing the upper step 10 to return to its original position. Multiple primary vibration damping devices 60 are also provided between the upper step 10 and the lower step 20. When the upper step 10 moves vertically and horizontally relative to the lower step 20, the primary vibration damping devices 60 provide cushioning.

[0050] The upper step 10 and lower step 20 of the caisson are sealed by a protective sealing layer 50. All the multiple first vibration damping and isolation devices 60 and second vibration damping and isolation devices 40 installed between the upper step 10 and lower step 20 are located in the chamber sealed by the protective sealing layer 50. This ensures that the joints of the caisson foundation with vibration damping and isolation function are isolated from the highly corrosive seawater environment, effectively protecting the first vibration damping and isolation devices 60 and the second vibration damping and isolation devices 40, and extending the service life of the caisson foundation with vibration damping and isolation function.

[0051] This invention, by setting up a protective chamber to seal the connection between the upper and lower steps of the caisson, effectively protects the first and second vibration damping and isolation devices, and extends the service life of the caisson foundation with vibration damping and isolation functions.

[0052] like Figure 1 , 2 As shown, in one embodiment, the upper step 10 of the caisson includes a first outer wall 12 arranged around the perimeter and a first inner wall 11 arranged in a crisscross pattern within the first outer wall 12; a plurality of second vibration damping and isolation devices 40 are respectively arranged at the connection between the first outer wall 12 and the first inner wall 11 and at the crisscrossing points of the first inner wall 11.

[0053] The first inner wall 11 with crisscrossing inside the caisson upper step 10 can increase the strength of the first outer wall 12. Compared with the hollow design, it has higher strength and is not easily damaged by water pressure. Compared with the solid design, it can reduce the weight of the caisson upper step 10 and reduce the amount of material used.

[0054] The present invention uses a first inner wall that is arranged in a crisscross pattern within the first outer wall, which can reduce the weight of the steps on the caisson while maintaining structural strength.

[0055] like Figure 1 As shown, in one embodiment, the sealing protective layer 50 includes: a first protective layer 51, which is disposed between the corbel 30 of the lower step 20 of the caisson and the first outer wall 12; a second protective layer 52, which is disposed between the top of the lower step 20 of the caisson and the first outer wall 12; the protective chamber 80 includes a first chamber 81; the first protective layer 51 and the second protective layer 52, together with the corbel 30 of the lower step 20 of the caisson and the upper step 10 of the caisson, form the first chamber 81; a plurality of first vibration damping and isolation devices 60 and a plurality of second vibration damping and isolation devices 40 disposed at the first outer wall 12 are sealed in the first chamber 81.

[0056] The outer side of the first outer wall 12 is sealed to the corbel 30 by the first protective layer 51, and the inner side of the first outer wall 12 is sealed to the caisson lower step 20 by the second protective layer 52. In this way, the lower side of the first outer wall 12 and the caisson lower step 20 form a first chamber 81 that is isolated from the outside world. The multiple first vibration damping and isolation devices 60 and second vibration damping and isolation devices 40 installed in the first chamber 81 are not in contact with the external environment, which increases the service life.

[0057] like Figure 1 , 2 As shown, in one embodiment, the sealing protective layer 50 further includes: a third protective layer 53 disposed between the top of the lower step 20 of the caisson and the intersection of the first inner wall 11; the protective chamber 80 further includes a second chamber 82; the third protective layer 53, the upper step 10 of the caisson, and the lower step 20 of the caisson together form a plurality of second chambers 82; a plurality of second vibration damping and isolation devices 40 disposed at the intersection of the first inner wall 11 are respectively sealed in the plurality of second chambers 82.

[0058] Multiple second vibration damping and isolation devices 40 are provided directly below the intersection of the first inner wall 11. A ring-shaped third protective layer 53 is provided on the outside of the second vibration damping and isolation device 40. The two ends of the opening of the third protective layer 53 are respectively sealed and connected to the upper step 10 and the lower step 20 of the caisson to form a second chamber 82 that encloses the second vibration damping and isolation device 40.

[0059] The present invention provides a second chamber for accommodating multiple second vibration damping and isolation devices located at the intersection of the first inner walls, thereby isolating the second vibration damping and isolation devices from the external environment and extending the service life of the second vibration damping and isolation devices located at the intersection of the first inner walls.

[0060] like Figure 1As shown, in one embodiment, the first chamber 81 and the second chamber 82 are filled with liquid grease.

[0061] Liquid grease has excellent lubricating and anti-corrosion properties, and compared with gas, liquid grease is not easily compressed. When the caisson foundation with vibration reduction and isolation function is placed in high-pressure seawater, the liquid grease inside the first chamber 81 and the second chamber 82 can provide the force to support the sealing protective layer 50, so that the sealing protective layer 50 is balanced inside and outside and is not easily damaged.

[0062] This invention enhances the corrosion resistance of the overall structure by filling the first and second chambers with liquid grease, and also provides support to protect the protective layer from damage by seawater pressure.

[0063] like Figure 1 As shown, in one embodiment, the first vibration damping device 60 includes: a spring 61, which is arranged parallel to the top of the lower step 20 of the caisson; and a viscous damper 62, which is arranged parallel to the top of the lower step 20 of the caisson.

[0064] like Figure 3 As shown, in one embodiment, the lower step 20 of the caisson includes a second outer wall 22 disposed around the perimeter and a second inner wall 21 disposed in a crisscross pattern within the second outer wall 22; the second inner wall 21 of the lower step 20 of the caisson is disposed correspondingly to the first inner wall 11 of the upper step 10 of the caisson.

[0065] like Figure 3 As shown, in one embodiment, the second inner wall 21 is thicker than the first inner wall 11, and the second outer wall 22 is thicker than the first outer wall 12.

[0066] The lower step 20 of the caisson is equipped with multiple intersecting second inner walls 21 and surrounding second outer walls 22, corresponding to the upper step 10 of the caisson. Since the lower step 20 is located below the upper step 10 and supports the upper step 10 and other building structures on the caisson foundation with seismic isolation function, the lower step 20 bears a greater load than the upper step 10. Therefore, the second inner walls 21 and the second outer walls 22 are thicker than the first inner walls 11 and the first outer walls 12, providing greater support. Similarly, the intersecting second inner walls 21 inside the lower step 20 not only increase the strength of the second outer walls 22 but also reduce the material required for the lower step 20.

[0067] like Figure 1 As shown, in one embodiment, it further includes: bottom sealing concrete 70, which is disposed at the bottom end of the lower step 20 of the caisson.

[0068] The bottom sealing concrete 70 at the bottom of the caisson step 20 serves the following purposes: 1. It isolates groundwater and external water from seeping into the caisson, providing a dry environment for subsequent construction; 2. As a foundation bearing layer, it evenly distributes the load of the superstructure such as bridges and buildings to the foundation soil layer; 3. It seals the bottom of the caisson to form an integral rigid foundation, preventing soil collapse or quicksand, and improving the caisson's anti-buoyancy capacity.

[0069] like Figure 1 , 2 As shown, in one embodiment, the second vibration damping and isolation device 40 is a friction pendulum vibration damping and isolation support.

[0070] The friction pendulum seismic isolation bearing has dual effects of seismic reduction and isolation. During an earthquake, the sliding surface of the bearing converts seismic energy into heat through friction, consuming seismic energy. The sliding interface material can adapt to large deformations and maintain stable frictional performance. Furthermore, the friction pendulum bearing can extend the structural period through spherical oscillation, avoiding the dominant seismic frequency band and reducing resonance effects. After an earthquake, the friction pendulum bearing can automatically reset under the weight of the structure, preventing residual displacement.

[0071] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0072] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0073] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A caisson foundation with seismic isolation and damping function, characterized in that, It includes: The caisson lower step (20) has a ring of corbels (30) around its top perimeter; the caisson lower step (20) includes a second outer wall (22) on all four sides and a second inner wall (21) arranged in a crisscross pattern within the second outer wall (22); The upper step (10) of the caisson includes a first outer wall (12) arranged around the perimeter and a first inner wall (11) arranged in a crisscross pattern within the first outer wall (12). The bottom end of the upper step (10) is placed at the top of the lower step (20) of the caisson and is located within a circle of corbels (30). The upper step (10) of the caisson can move relative to the lower step (20) of the caisson. The second inner wall (21) of the lower step (20) of the caisson is correspondingly provided with the first inner wall (11) of the upper step (10) of the caisson. The second inner wall (21) is thicker than the first inner wall (11), and the second outer wall (22) is thicker than the first outer wall (12). Multiple first vibration damping and isolation devices (60) are provided, each comprising: a spring (61) which is arranged parallel to the top of the lower step (20) of the caisson; a viscous damper (62) which is arranged parallel to the top of the lower step (20) of the caisson; the multiple first vibration damping and isolation devices (60) are provided between the corbel (30) and the upper step (10) of the caisson; Multiple second vibration damping and isolation devices (40), the second vibration damping and isolation devices (40) are friction pendulum vibration damping and isolation supports, which are located between the lower step (20) of the caisson and the upper step (10) of the caisson; multiple second vibration damping and isolation devices (40) are respectively located at the connection between the first outer wall (12) and the first inner wall (11) and at the intersection of the first inner wall (11); A sealing protective layer (50) is disposed between the lower step (20) and the upper step (10) of the caisson, and forms a protective chamber (80) with the lower step (20) and the upper step (10) of the caisson. A plurality of first vibration damping and isolation devices (60) and second vibration damping and isolation devices (40) are disposed in the protective chamber (80). The sealing protective layer (50) includes: a first protective layer (51) disposed between the corbel (30) of the lower step (20) of the caisson and the first outer wall (12); a second protective layer (52) disposed between the top of the lower step (20) of the caisson and the first outer wall (12); and a third protective layer (53) disposed between the top of the lower step (20) of the caisson and the intersection of the first inner wall (11). The protective chamber (80) includes: a first chamber (81), formed by the first protective layer (51) and the second protective layer (52) together with the corbel (30) of the lower step (20) of the caisson and the upper step (10) of the caisson; a second chamber (82), formed by the third protective layer (53) together with the upper step (10) of the caisson and the lower step (20) of the caisson; the first chamber (81) and the second chamber (82) are filled with liquid grease; a plurality of first vibration damping and isolation devices (60) and a plurality of second vibration damping and isolation devices (40) located at the first outer wall (12) are sealed in the first chamber (81); a plurality of second vibration damping and isolation devices (40) located at the intersection of the first inner wall (11) are respectively sealed in the plurality of second chambers (82).

2. A caisson foundation with seismic isolation function according to claim 1, characterized in that, Also includes: The bottom sealing concrete (70) is located at the bottom end of the lower step (20) of the caisson.

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