Anti-faulting buffer device suitable for high-cold high-altitude high-seismic intensity conditions

Abstract

The present application relates to the technical field of building foundation earthquake resistance, and proposes an anti-faulting buffer device suitable for high-cold, high-altitude and high-seismic-intensity conditions, which comprises a foundation frame (1), a connecting component (2), a load-bearing assembly (3), and a buffer assembly (4) for buffering external pressure and seismic energy; the foundation frame (1) is hollow, the load-bearing assembly (3) and the buffer assembly (4) are arranged in the foundation frame (1), the first end of the connecting component (2) is connected with the load-bearing assembly (3) in the foundation frame (1), the second end of the connecting component (2) penetrates out of the foundation frame (1) and is connected with a device outside the anti-faulting buffer device which needs to be anti-faulting buffered, one end of the buffer assembly (4) is connected with the load-bearing assembly (3), and the other end is connected with the inner surface of the foundation frame (1); the device has adaptability and anti-risk ability under high-cold, high-altitude and high-seismic extreme conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building foundation anti-seismic, more particularly to an anti-disconnection buffer device suitable for high-cold high-altitude high-seismic-intensity conditions. BACKGROUND

[0002] With the rapid development of China's economy and the acceleration of urbanization process, the demand for electricity continues to grow, and the construction of power transmission network is increasingly important. In particular, with the widespread application of renewable energy (such as wind energy, solar energy), direct current transmission technology is valued for its efficiency and low loss characteristics in long-distance power transmission. The state vigorously promotes ultra-high voltage direct current transmission projects to realize cross-regional power dispatching and resource optimization, and to ensure the safety and stability of power supply. However, as the power transmission line extends, especially in high-cold, high-altitude and high-seismic-intensity areas, the design and construction of line foundations, including tower foundations, face new challenges. The tower body is generally referred to as the superstructure, and the part of the tower other than the superstructure is referred to as the foundation.

[0003] Under high-cold, high-altitude and high-seismic-intensity conditions, the existing power transmission line foundation design technology has many shortcomings. First, the low-temperature environment in high-cold areas can cause embrittlement of traditional materials, affecting the bearing capacity and stability of the foundation. Second, the special geological conditions and climate changes in high-altitude areas make the soil properties complex, and traditional foundation design is difficult to adapt. In addition, in high-seismic-intensity areas, existing anti-seismic design often cannot effectively cope with extreme seismic loads, resulting in foundation disconnection, deformation or failure, thereby affecting the safety of power transmission. Therefore, a new anti-disconnection buffer technology is needed to improve the adaptability and risk resistance of the foundation under these extreme conditions. SUMMARY

[0004] The present application is to overcome the defects of the prior art that cannot adapt to high-cold, high-altitude and / or high-seismic-intensity conditions, and provides an anti-disconnection buffer device suitable for high-cold, high-altitude and high-seismic-intensity conditions, which can maintain good performance under high-cold, high-altitude and / or high-seismic-intensity conditions.

[0005] To solve the above technical problems, the technical solution of the present application is as follows:

[0006] The anti-disconnection buffer device suitable for high-cold, high-altitude and high-seismic-intensity conditions comprises a foundation frame, a connecting component, a load-bearing assembly, and a buffer assembly for buffering external pressure and seismic energy.

[0007] The base frame is internally hollow, the load-bearing assembly and the buffer assembly are arranged in the base frame, the first end of the connecting component is connected with the load-bearing assembly in the base frame, the second end of the connecting component is connected with the device needing to be anti-disconnection and buffer outside the anti-disconnection buffer device, one end of the buffer assembly is connected with the load-bearing assembly, and the other end is connected with the inner surface of the base frame.

[0008] Compared with the prior art, the beneficial effects of the technical scheme of the present application are:

[0009] The components in the base frame are protected by the base frame, the load-bearing assembly provides support force for the device needing to be anti-disconnection and buffer, thereby the load-bearing capacity and stability of the anti-disconnection buffer device are strengthened, the impact force brought by abnormal conditions such as earthquakes is buffered by the buffer assembly, and the phenomena such as disconnection, deformation or failure of the anti-disconnection buffer device are prevented, so that the anti-disconnection buffer device has adaptability and anti-risk ability under extreme conditions of high cold, high altitude and high earthquake intensity. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The cross-sectional structure diagram of the anti-disconnection buffer device suitable for high-cold high-altitude high-seismic-intensity conditions for example 1 is shown.

[0011] Figure 2 The structure diagram of the anti-disconnection buffer device suitable for high-cold high-altitude high-seismic-intensity conditions for example 1 is shown.

[0012] Figure 3 The structure diagram of the pressing plate for example 1 is shown.

[0013] Figure 4 The vertical cross-sectional diagram of the connecting component for example 2 is shown.

[0014] 1-base frame, 2-connecting component, 21-base, 211-connection hole, 22-shock resistance filler, 3-load-bearing assembly, 31-pressing plate, 311-first sub-pressing plate, 312-second sub-pressing plate, 313-third sub-pressing plate, 32-supporting rod, 4-buffer assembly, 41-first spring, 42-second spring, 43-connection bolt, 5-frame rod, 6-buffer pad, 7-precast solid pier. DETAILED DESCRIPTION

[0015] The drawings are only used for illustrative description and cannot be understood as a limitation of the present embodiment;

[0016] In order to better illustrate the present embodiment, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual product size;

[0017] It is understood by those skilled in the art that certain well-known structures and their descriptions can be omitted in the drawings.

[0018] The technical solutions of the present application will be further described below in combination with the drawings and examples.

[0019] Example 1

[0020] This embodiment proposes an anti-faulting buffer device suitable for high-cold high-altitude high-seismic-intensity conditions, Figure 1 This embodiment proposes a cross-sectional structure diagram of an anti-faulting buffer device suitable for high-cold high-altitude high-seismic-intensity conditions; Figure 2 This embodiment proposes a structure diagram of an anti-faulting buffer device suitable for high-cold high-altitude high-seismic-intensity conditions;

[0021] In the anti-faulting buffer device suitable for high-cold high-altitude high-seismic-intensity conditions proposed in this embodiment, it comprises a base frame 1, a connecting component 2, a load-bearing assembly 3, and a buffer assembly 4 for buffering external pressure and seismic energy.

[0022] The base frame 1 is hollow inside, the load-bearing assembly 3 and the buffer assembly 4 are arranged in the base frame 1, the first end of the connecting component 2 is connected with the load-bearing assembly 3 in the base frame 1, the second end of the connecting component 2 penetrates out of the base frame 1 and is connected with a device outside the anti-faulting buffer device that needs to be anti-faulting buffered, one end of the buffer assembly 4 is connected with the load-bearing assembly 3, and the other end is connected with the inner surface of the base frame 1.

[0023] In the specific implementation process, the base frame is used to protect the components in the base frame, the load-bearing assembly is used to provide support force for the device that needs to be anti-faulting buffered, thereby enhancing the load-bearing capacity and stability of the anti-faulting buffer device, the buffer assembly is used to buffer the impact force brought by abnormal conditions such as earthquakes, and prevent the anti-faulting buffer device from appearing faulting, deformation or failure, etc., so that the anti-faulting buffer device has adaptability and anti-risk ability under high-cold, high-altitude and high-seismic extreme conditions.

[0024] In an optional embodiment, the load-bearing assembly 3 comprises a pressing plate 31 and a support rod 32, one plane of the pressing plate 31 is connected with the first end of the connecting component 2, the other plane of the pressing plate 31 is connected with one end of the support rod 32, the other end of the support rod 32 is connected with the inner surface of the base frame 1, and the four side surfaces of the pressing plate 31 are connected with the inner surface of the base frame 1.

[0025] As an exemplary illustration, the number of support rods 32 can be adjusted according to actual needs. In this embodiment, four support rods are selected. From the perspective of construction cost: four support columns may be slightly higher than three support columns, but they have a cost advantage over five support columns, because an additional support column significantly increases material and construction costs. Four support columns are relatively simpler to install, especially in complex terrain and conditions. The installation of five columns may require more complex techniques and more human resources. The maintenance of four support columns is relatively simple, the number of columns is moderate, and the workload for detection and maintenance is less, and the complexity of maintenance is not easily increased. From the perspective of support force: four support columns provide a more balanced force distribution, reducing the risk of excessive load on a single column compared to three columns. In high-cold, high-altitude, and high-seismic intensity conditions, the design of four support columns can effectively disperse seismic stress and improve seismic performance. One more than three support columns provides a certain redundancy, enhancing the safety of the overall structure. If one of the columns has a problem, the other columns can share more load. Compared to five support columns, the four-column design simplifies the mechanical calculation, ensures uniform distribution of support force without overcomplicating it, and can provide better anti-break and buffering effects, adapting to harsh environmental conditions.

[0026] In an optional embodiment, a plurality of frame rods 5 are arranged in the base frame 1, and the frame rods 5 are used to support the base frame 1.

[0027] In an optional embodiment, the anti-break buffering device further comprises a buffering pad 6 arranged between the frame rod 5 and the pressing plate 31.

[0028] As an exemplary illustration, as shown in Figure 1 a plurality of frame rods 5 are arranged in the base frame 1. The frame rods 5 are divided into two parts. The two ends of the first part of the frame rods 5 are respectively connected to the two opposite sides of the base frame 1, and the two ends of the second part of the frame rods 5 are respectively connected to the top and bottom surfaces of the base frame 1. As an exemplary illustration, as shown in Figure 1 the buffering pad 6 is arranged between the first part of the frame rod 5 and the pressing plate 31.

[0029] In an optional embodiment, the pressing plate 31 comprises a first sub-pressing plate 311, a second sub-pressing plate 312, and a third sub-pressing plate 313 connected in sequence. The first sub-pressing plate 311 and the third sub-pressing plate 313 are used to bear pressure, and the second sub-pressing plate 312 is used to absorb external force.

[0030] As an exemplary illustration, Figure 3 the structure diagram of the pressing plate proposed in this embodiment, Figure 3The pressing plate 31 comprises a first sub-pressing plate 311, a second sub-pressing plate 312 and a third sub-pressing plate 313 connected in sequence.

[0031] As an example, as shown in the figure, one side of the first sub-pressing plate 311 is connected with the connecting component 2, and the other side is connected with one side of the second sub-pressing plate 312. The other side of the second sub-pressing plate 312 is connected with one side of the third sub-pressing plate 313, and the other side of the third sub-pressing plate 313 is connected with the support rod. Figure 3

[0032] In an optional embodiment, the first sub-pressing plate 311 and the third sub-pressing plate 313 are made of alloy material.

[0033] As an example, the first sub-pressing plate 311 and the third sub-pressing plate 313 are made of rigid material, preferably alloy material, and preferably steel.

[0034] In an optional embodiment, the second sub-pressing plate 312 is made of rubber, polyurethane or other elastic composite material.

[0035] As an example, the second sub-pressing plate 312 is made of flexible material, preferably rubber, polyurethane or other elastic composite material.

[0036] In this optional embodiment, the purpose of using three layers of buffer pressing plate is to enhance the anti-seismic and anti-disconnection ability of the structure. The rigid buffer pressing plates on the uppermost layer and the lowermost layer can bear the pressure of the upper structure, ensuring the stability and carrying capacity of the structure. The flexible buffer pressing plate in the middle absorbs and disperses the stress generated by the earthquake, reducing the impact on the overall structure and improving the anti-seismic performance. Compared with two layers of buffer pressing plate, three layers of buffer design can provide an additional buffer, further reducing the impact of the earthquake on the structure and improving the overall safety and durability. The rigid buffer pressing plate can be made of high-strength steel or other high-strength alloy material, which can provide sufficient strength and durability. The flexible buffer pressing plate can use rubber, polyurethane or other elastic composite material to effectively absorb and buffer vibration and impact.

[0037] Embodiment 2

[0038] This embodiment proposes an anti-disconnection buffer device suitable for high-cold high-altitude high-seismic-intensity conditions, which is improved based on the anti-disconnection buffer device suitable for high-cold high-altitude high-seismic-intensity conditions proposed in Embodiment 1.

[0039] The anti-disconnection buffer device suitable for high-cold high-altitude high-seismic-intensity conditions proposed in this embodiment comprises a base frame 1, a connecting component 2, a bearing assembly 3, and a buffer assembly 4 for buffering external pressure and seismic energy.​

[0040] The base frame 1 is hollow, the load-bearing assembly 3 and the buffer assembly 4 are arranged in the base frame 1, the first end of the connecting component 2 is connected with the load-bearing assembly 3 in the base frame 1, the second end of the connecting component 2 penetrates out of the base frame 1 and is connected with the device to be protected from breakage outside the anti-breakage buffer device, one end of the buffer assembly 4 is connected with the load-bearing assembly 3, and the other end is connected with the inner surface of the base frame 1.

[0041] In the specific implementation process, the base frame is used to protect the components in the base frame, the load-bearing assembly is used to provide support force for the device to be protected from breakage, thereby enhancing the carrying capacity and stability of the anti-breakage buffer device, the buffer assembly is used to buffer the impact force brought by abnormal conditions such as earthquakes, and the anti-breakage buffer device is prevented from breaking, deforming or failing, so that the anti-breakage buffer device has adaptability and risk resistance ability under extreme conditions of high cold, high altitude and high earthquake.

[0042] In an optional embodiment, the load-bearing assembly 3 includes a pressing plate 31 and a support rod 32, one plane of the pressing plate 31 is connected with the first end of the connecting component 2, the other plane of the pressing plate 31 is connected with one end of the support rod 32, the other end of the support rod 32 is connected with the inner surface of the base frame 1, and the four side surfaces of the pressing plate 31 are connected with the inner surface of the base frame 1.

[0043] In an optional embodiment, the buffer assembly 4 includes a first spring 41 and / or a second spring 42.

[0044] When the buffer assembly 4 includes the first spring 41, the support rod 32 is connected with the inner surface of the base frame 1 through the first spring 41.

[0045] When the buffer assembly 4 includes the second spring 42, the total number of the second springs 42 is greater than or equal to 1, the second springs 42 are used to connect the side surfaces of the support rod 32 and the side surfaces of the inner surface of the base frame 1, and if the number of the support rods 32 is greater than 1, the second springs 42 are also used to connect the support rods 32 together.

[0046] As an exemplary illustration, when the buffer assembly 4 includes the second spring 42, the buffer assembly 4 also includes a connecting bolt 43, and the connecting bolt 43 is used to fix the second spring 42.

[0047] As an illustrative example, in a normal stress state, both the first spring 41 and the second spring 42 are in a state of no deformation. When an external environment suddenly changes and an abnormal external force is applied to the device, the first spring 41 and the second spring 42 deform to generate resistance to buffer the abnormal external force, so as to prevent the abnormal external force from impacting the anti-breakage buffer device, thereby avoiding phenomena such as breakage, deformation, or failure of the device. For example, when the second spring 42 is connected horizontally as usual, if an earthquake occurs, the second spring 42 can effectively counteract the horizontal seismic force. Figure 1

[0048] As an illustrative example, Figure 1 It is shown that the support rod is 4, and the buffer assembly 4 includes both the first spring 41 and the second spring 42.

[0049] In an optional embodiment, the device that needs to be buffered against breakage is connected to the connecting component 2 through a prefabricated solid pier 7, and the connecting component 2 includes a base 21 with a connecting hole 211 and a shock-resistant filler 22, which fills the connecting hole 211 after the prefabricated solid pier 7 is inserted into the connecting hole 211.

[0050] As an illustrative example, the device that needs to be buffered against breakage includes an upper structure.

[0051] In an optional embodiment, the vertical cross-sectional shape of the connecting hole 211 of the base 21 includes a trapezoidal ladder, the upper base and the lower base of the trapezoidal ladder are parallel, the waist is ladder-shaped, and the upper base of the trapezoidal ladder is larger than the lower base.

[0052] As an illustrative example, Figure 4 The vertical cross-sectional view of the connecting component proposed in this embodiment.

[0053] The key points of this embodiment include designing a special anti-breakage structure combined with high-performance buffer materials to effectively absorb the impact force caused by seismic waves, enhancing the stability and safety of the foundation. In addition, this embodiment also covers material selection for extreme climates and construction and maintenance methods for high-altitude areas to ensure the reliability and durability of infrastructure in harsh environments. These innovations collectively constitute comprehensive protection for this embodiment, aiming to improve the operational safety of DC lines under extreme conditions.

[0054] It can be understood that the anti-breakage buffer device of this embodiment improves the method of embodiment 1, and the options in the above embodiment 1 are also applicable to this embodiment, so they are not described again here.

[0055] Embodiment 3

[0056] ​The anti-fault buffer device suitable for high-cold, high-altitude and high-seismic intensity conditions is proposed based on the embodiments 1 and 2, and a specific implementation example is proposed.

[0057] In this embodiment, the base 21 is selected as a cup mouth base, the first spring 41 is called a buffer spring, the second spring 42 is called a sliding assembly, and the pressing plate 31 is called a top pressing plate.

[0058] The overall structure of the device proposed in this embodiment includes a base frame, a buffer spring, a support rod, a sliding assembly, a top pressing plate, a shock-resistant filler, and a connecting bolt. Each part has its unique function to ensure the safety and stability of the system. The base frame is the core skeleton of the entire device, made of high-strength weather-resistant material. This material can provide excellent durability and stability in high-cold, high-altitude and high-seismic intensity environmental conditions. The top pressing plate is composed of two anti-seismic materials. The design of the frame aims to enhance its anti-fracture ability in extreme weather conditions, especially in high-vibration and external force impact. The buffer spring is installed below the support rod and is one of the key components of the device. They are designed to absorb and alleviate the impact force and seismic energy from the outside, reducing the risk of vibration transmission to the upper structure. The material and design of the spring are carefully selected to ensure that it can provide sufficient support while adapting to a certain deformation when impacted, thereby reducing the possibility of structural damage. The support rod serves to connect and transfer loads, ensuring the stability between the buffer spring and the top pressing plate. The sliding assembly allows the support structure to make slight adjustments when stressed to adapt to the deformation caused by external forces, reducing the risk of overall structural fracture. Such design improves the flexibility and stability of the system under external impact. The top pressing plate is tightly connected to the shell through bolts, further dispersing the pressure from the outside. The design of the pressing plate not only resists fatigue loss caused by high vibration, but also maintains stability under long-term high pressure. The shock-resistant filler is directly connected to the upper structure through the precast solid pier, and the shock-resistant filler surrounds the upper structure. The shock-resistant filler has multiple characteristics such as compressibility, shock resistance, and compactness. Considering the stress condition of the upper structure, the distribution of the shock-resistant filler in the vertical section is also a trapezoidal distribution from large at the top to small at the bottom, as shown in Figure 1 .

[0059] The connecting bolts ensure a tight connection between the components, preventing the risk of breakage due to long-term stretching or compression. In addition, all core components are made of low-temperature-resistant and corrosion-resistant materials to protect the internal structure from the erosion of harsh environments. The choice of these materials not only adapts to extreme climates, but also maintains good mechanical properties in cold and high-altitude areas. In summary, the device effectively solves the problem of breakage and failure of traditional foundations in extreme conditions through sophisticated mechanical design and material selection. It significantly enhances the anti-seismic and anti-impact capabilities of the direct current line foundation, ensuring the safety and long-term stable operation of the power transmission system in complex environments.

[0060] The invention first optimizes the design of the foundation structure, adopting a multi-level, multi-material combined foundation form to enhance its load-bearing capacity and anti-break performance. The foundation design takes into account the special geological conditions of high-cold, high-altitude and high-seismic intensity areas, ensuring that the foundation can effectively disperse and transfer loads, reducing lateral vibration caused by earthquakes or other dynamic loads. The invention includes two main parts: the pillar structure (load-bearing component) and the buffer system (buffer component). The pillar structure is designed to be reinforced to withstand the harsh conditions of high-cold and high-altitude environments. Each pillar is equipped with a spring system at the bottom, which can absorb and alleviate the vibration and impact force caused by seismic activity. This spring configuration helps prevent excessive movement and damage to the foundation structure during an earthquake, avoiding the risk of breakage of the upper structure and causing power system interruptions.

[0061] In terms of material selection, the invention uses materials with excellent low-temperature performance and high-strength characteristics, such as modified polymers, special synthetic rubbers and high-strength composite materials. These materials maintain good elasticity and toughness in low-temperature environments, avoiding structural failure due to embrittlement. At the same time, the lightweight nature of the materials helps reduce the self-weight of the foundation, improving overall stability. In addition, the foundations are connected by reinforced transverse connecting rods, enhancing the lateral stability of the overall structure, which is very important for resisting lateral forces generated during an earthquake. This design not only improves the anti-seismic performance of the foundation, but also effectively disperses and transfers seismic forces, reducing stress concentration at individual points and improving the overall anti-break performance of the system.

[0062] The invention introduces a new anti-break buffer system, which includes an elastic buffer layer (buffer component). The elastic buffer layer is placed between the foundation and the ground, effectively absorbing ground vibration energy and reducing the impact of lateral vibration.

[0063] In summary, the application provides a DC line foundation anti-breakage buffer device suitable for high-cold, high-altitude and high-seismic-intensity conditions, aiming to solve the problem of the vulnerability and insufficient anti-seismic capability of the foundation structure in the prior art under extreme environment. The device significantly improves the anti-breakage capability and overall stability of the foundation by optimizing the foundation design, selecting new materials and introducing advanced damping and buffering mechanisms; by optimizing the design, material innovation and advanced damping mechanisms, the anti-breakage capability of the foundation is significantly improved, providing a strong guarantee for the safe operation of the power transmission network under special environment. The technology has a wide application prospect and provides an innovative solution for the development of future power infrastructure.

[0064] The same or similar reference signs correspond to the same or similar components;

[0065] The terms describing the positional relationship in the drawings are only used for illustrative description, and should not be understood as a limitation on the embodiments of the present application;

[0066] Obviously, the above embodiments of the application are only examples for clearly illustrating the application, and are not intended to limit the embodiments of the application. Based on the above description, those skilled in the art can make other different forms of changes or modifications. Here, it is not necessary and impossible to enumerate all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the application should be included in the protection scope of the claims of the application.

Claims

1. A fault-resistant buffer device suitable for high-cold high-altitude high-seismic-intensity conditions, characterized in that, The anti-disconnection buffer device comprises a base frame (1), a connecting component (2), a load-bearing assembly (3), and a buffer assembly (4) for buffering external pressure and seismic energy. The base frame (1) is hollow, the load-bearing assembly (3) and the buffer assembly (4) are arranged in the base frame (1), the first end of the connecting component (2) is connected with the load-bearing assembly (3) in the base frame (1), the second end of the connecting component (2) is connected with a device needing to be buffered against disconnection outside the anti-disconnection buffer device, one end of the buffer assembly (4) is connected with the load-bearing assembly (3), and the other end is connected with the inner surface of the base frame (1). The load-bearing assembly (3) comprises a pressing plate (31) and a support rod (32), one plane of the pressing plate (31) is connected with the first end of the connecting component (2), the other plane of the pressing plate (31) is connected with one end of the support rod (32), the other end of the support rod (32) is connected with the inner surface of the base frame (1), and the four side surfaces of the pressing plate (31) are connected with the inner surface of the base frame (1). A plurality of frame rods (5) are arranged in the base frame (1) and used for supporting the base frame (1). The anti-disconnection buffer device further comprises a buffer pad (6) arranged between the frame rod (5) and the pressing plate (31). The pressing plate (31) comprises a first sub-pressing plate (311), a second sub-pressing plate (312), and a third sub-pressing plate (313) connected in sequence, the first sub-pressing plate (311) and the third sub-pressing plate (313) are used for bearing pressure, and the second sub-pressing plate (312) is used for absorbing external force. The first sub-pressing plate (311) and the third sub-pressing plate (313) are made of alloy material. The second sub-pressing plate (312) is made of rubber, polyurethane, or other elastic composite material. The buffer assembly (4) comprises a first spring (41) and / or a second spring (42). When the buffer assembly (4) comprises the first spring (41), the support rod (32) is connected with the inner surface of the base frame (1) through the first spring (41). When the buffer assembly (4) comprises the second spring (42), the total number of the second springs (42) is greater than or equal to 1, the second springs (42) are used for connecting the side surface of the support rod (32) and the side surface of the inner surface of the base frame (1), and if the number of the support rods (32) is greater than 1, the second springs (42) are also used for connecting the support rods (32) together. The device needing to be buffered against disconnection is connected with the connecting component (2) through a prefabricated solid pier (7), the connecting component (2) comprises a base (21) provided with a connecting hole (211) and a shock-resistant filler (22), and the shock-resistant filler (22) fills the connecting hole (211) after the prefabricated solid pier (7) is inserted into the connecting hole (211). The vertical sectional shape of the connecting hole (211) of the base (21) comprises a trapezoidal ladder, the upper base and the lower base of the trapezoidal ladder are parallel, the waist is in a ladder shape, and the upper base of the trapezoidal ladder is larger than the lower base.

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