A wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure

Abstract

The present invention discloses a wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure. The outer frame of the model is connected to the wind tunnel chassis through a pedestal. Vertically, a rigid mass block is connected to the outer frame of the model through a compression spring and is fixed in position by a frustum. Horizontally, the rigid mass block is connected to the outer frame of the model through a hook, a tension spring, and a hook plate. The rigid mass block bears the superstructure through a cap. A cover plate is located above the outer frame of the model and is fixed to the wind tunnel floor. The upper surface of the cover plate is flush with the wind tunnel floor. The number of hooks, the number of frustums, and the stiffness of the tension and compression springs are obtained through finite element and scaling theory calculations. The present invention can realize the model simulation of the lower structure such as soil - pile - cap of buildings or structures in a wind tunnel and realize the research on the interaction of soil - pile - cap - superstructure in a wind tunnel.

Description

Technical Field

[0001] The present invention belongs to a wind tunnel test device in the technical field of building structures, and particularly relates to a wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure. Background Technique

[0002] Wind disasters are the most common natural disasters. China is one of the few countries in the world that are most severely affected by typhoons. When conducting wind resistance design for existing buildings, generally, the influence of lower structures such as foundations and sub - structures is not taken into account. Instead, a rigid foundation model is adopted, and the obtained wind loads are summarized into base forces and base moments, which are then used as input loads for the separate design of the foundation. However, in actual situations, after a building is subjected to external load excitation, energy will be transmitted downward through the vibration of the tower body and finally reach the soil at the bottom of the building. After being excited, the soil also starts to vibrate and reacts back on the structure, forming a coupling mechanism, that is, the interaction of soil - pile - superstructure. Especially for high - rise, light, and flexible structures such as super high - rise buildings and chimneys, they are more sensitive to wind loads. Therefore, the interaction of soil - pile - superstructure has a significant impact on the wind load response of buildings. A large number of research works by domestic and foreign scholars have shown that the influence of the deformation of the foundation and sub - structure on the wind - induced response of the structure should not be ignored.

[0003] Due to the limitations of wind tunnel equipment, the existing wind tunnel tests cannot consider the influence of lower structures (including piles, soil, and caps), and the final results obtained cannot reflect the interaction of soil - pile - cap - superstructure.

[0004] Therefore, the existing technology lacks a wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure. Summary of the Invention

[0005] The purpose of the present invention is to provide a wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure, which can realize the model simulation of the lower structure of a building such as soil - pile - cap in a building wind tunnel and carry out the research on the interaction of soil - pile - cap - superstructure in a building wind tunnel.

[0006] The technical solution adopted by the present invention to solve its technical problems is:

[0007] The wind tunnel test device includes a model outer frame, a rigid mass block, an upper structure, a compression spring, a tension spring, a hook plate, a base, a wind tunnel chassis, a hook, a round table, a bearing platform, and a cover plate; the model outer frame is connected to a rotatable wind tunnel chassis through the base, a rigid mass block is arranged inside the model outer frame, and the rigid mass block is connected to the model outer frame through a compression spring and a tension spring; the rigid mass block carries the upper structure through the bearing platform; the cover plate is located on the model outer frame and fixed to the wind tunnel floor; the upper surface of the cover plate is flush with the wind tunnel floor; the upper structure is located above the cover plate, and the bearing platform moves through the middle hole of the cover plate; the bottom end of the bearing platform is fixedly connected to the upper surface of the rigid mass block, and the top end of the bearing platform is fixedly connected to the bottom end of the upper structure.

[0008] The model outer frame is fixed on a base, and the base is fixed on a wind tunnel chassis.

[0009] The four vertical surfaces around the rigid mass block are each arranged M hooks; hook plates are arranged on the four inner wall surfaces around the outer frame of the model, and the hook plates are connected to the hooks through tension springs.

[0010] The top and bottom surfaces of the rigid mass block are elastically connected to the ceiling and floor of the model outer frame through respective compression springs, and the surrounding side surfaces of the rigid mass block are elastically connected to the surrounding inner walls of the model outer frame through respective tension springs.

[0011] The upper and lower surfaces of the rigid mass block are arranged N The middle position between the ceiling and the floor inside the outer frame of the model is arranged with N In the vertical direction, the positions of the frustum on the ceiling of the model outer frame correspond one-to-one with the positions of the frustum on the upper surface of the rigid mass block, and the positions of the frustum on the floor of the model outer frame correspond one-to-one with the positions of the frustum on the lower surface of the rigid mass block, and the frustums with corresponding positions are connected by compression springs.

[0012] The number of hooks described M , Number of cones N , compression spring stiffness and tension spring stiffness are obtained through finite element simulation and scaled theoretical calculation.

[0013] The top surface of the base is lower than the wind tunnel floor, and the joint between the upper structure and the pedestal, the upper surface of the cover plate and the wind tunnel floor are flush with each other.

[0014] The device is used to simulate a single-cap foundation or a multi-cap foundation.

[0015] The device is used to simulate a pile-supported platform structure, or to simulate a foundation without piles.

[0016] The device of the present invention is used to simulate a single pile cap foundation or a multi-pile cap foundation. By changing the number of the model outer frames and rigid mass blocks, the wind tunnel test of the interaction between soil - pile - pile cap - superstructure of a single foundation structure and a multi - foundation structure can be realized.

[0017] The device of the present invention is used to simulate a pile - supported platform structure or a foundation without piles, such as a raft foundation.

[0018] In specific implementation, the superstructure 3 is a building structure such as a building or a tower.

[0019] In the solution of the present invention, the rigid mass block 2 and the pile cap 11 are equivalently used as the pile cap, and the compression spring 4 and the tension spring 5 are equivalently used as the soil and the pile, so as to form a simulation environment for the interaction between soil - pile - pile cap - superstructure.

[0020] The beneficial effects of the present invention are as follows:

[0021] The present invention can realize the model simulation of the lower structure of a building or structure in a wind tunnel, such as soil - pile - pile cap, make the wind tunnel test results closer to the actual situation, and realize the research on the interaction between soil - pile - pile cap - superstructure in a wind tunnel. Description of the Drawings

[0022] Figure 1 is the wind tunnel schematic diagram of the device of the present invention.

[0023] Figure 2 is the overall schematic diagram of the device of the present invention.

[0024] Figure 3 is the overall exploded schematic diagram of the device of the present invention.

[0025] Figure 4 is the internal perspective view of the model outer frame.

[0026] In the figure: 1. Model outer frame, 2. Rigid mass block, 3. Superstructure, 4. Compression spring, 5. Tension spring, 6. Hook plate, 7. Base, 8. Wind tunnel chassis, 9. Hook, 10. Frustum, 11. Pile cap, 12. Wind tunnel ground, 13. Cover plate. Detailed Implementation Modes

[0027] The present invention will be further described below in conjunction with the drawings and embodiments.

[0028] As Figure 2 , Figure 3As shown in the figure, it includes an outer frame 1 of the model, a rigid mass block 2, an upper structure 3, a compression spring 4, a tension spring 5, a hook plate 6, a base 7, a wind tunnel chassis 8, a hook 9, a frustum 10, a bearing platform 11, and a cover plate 13. The outer frame 1 of the model is connected to the rotatable wind tunnel chassis 8 through the base 7. A rigid mass block 2 is arranged inside the outer frame 1 of the model, and the rigid mass block 2 is connected to the outer frame 1 of the model through the compression spring 4 and the tension spring 5 (for the sake of simplicity in the figure, only one tension spring and one compression spring are shown respectively in the figure). The rigid mass block 2 bears the upper structure 3 through the bearing platform 11. The cover plate 13 is located above the outer frame 1 of the model and is fixed to the wind tunnel floor 12. The upper surface of the cover plate 13 is flush with the wind tunnel floor 12. The upper structure 3 is located above the cover plate 13. The bearing platform 11 passes through the middle hole of the cover plate 13 movably, and there is no connection or contact between the bearing platform 11 and the middle hole of the cover plate 13. The bottom end of the bearing platform 11 is fixedly connected to the upper surface of the rigid mass block 2, and the top end of the bearing platform 11 is fixedly connected to the bottom end of the upper structure 3.

[0029] The outer frame 1 of the model is fixed on the base 7, and the base 7 is fixed on the wind tunnel chassis 8.

[0030] As Figure 4 shown, on each of the four vertical surfaces around the front, rear, left, and right of the rigid mass block 2, M hooks 9 are arranged. M Take 6. Hook plates 6 are arranged on each of the four inner wall surfaces around the front, rear, left, and right of the outer frame 1 of the model. The hook plates 6 are connected to the hooks 9 through the tension springs 5.

[0031] The top and bottom surfaces of the rigid mass block 2 are elastically connected to the ceiling and floor of the outer frame 1 of the model through their respective compression springs 4, and the surrounding side surfaces of the rigid mass block 2 are elastically connected to the surrounding inner walls of the outer frame 1 of the model through their respective tension springs 5.

[0032] The compression spring 4 has a compression effect, and the tension spring 5 has a tension effect.

[0033] On the upper and lower surfaces of the rigid mass block 2, N frustums 10 are arranged. N Take 8. The outer frame 1 of the model is a cuboid with an openable cover. At the middle positions between the ceiling and the floor inside the outer frame 1 of the model, N frustums 10 are arranged. N Take 8. In the vertical direction, the frustums 10 on the ceiling of the outer frame 1 of the model correspond to the frustums 10 on the upper surface of the rigid mass block 2 in position and are located on the same vertical line. The frustums 10 on the floor of the outer frame 1 of the model correspond to the frustums 10 on the lower surface of the rigid mass block 2 in position and are located on the same vertical line. And the corresponding frustums 10 are connected by the compression springs 4.

[0034] Vertically, the upper and lower surfaces of the rigid mass block 2 are respectively connected to the ceiling and floor of the model outer frame 1 through compression springs 4, and the position is fixed by a frustum 10 to prevent instability. Horizontally, the four vertical surfaces of the front, back, left and right of the rigid mass block 2 are connected to the model outer frame 1 through hooks 9, tension springs 5 and hook plates 6, and the working tension is generated by adjusting the position of the hook plate 6.

[0035] Number of hooks M , and the number of frustums N , the stiffness of the compression spring 4 and the stiffness of the tension spring 5 are obtained through finite element simulation and reduced scale theory calculation.

[0036] In specific implementation, first establish a finite element model of soil-pile-cap in the ABAQUS finite element software, and then conduct load analysis to obtain the stiffness of the finite element model in 6 directions. Then, through the conversion of the model scale ratio, the actual spring stiffness is obtained, and appropriate compression springs 4 and tension springs 5 are selected according to the translational stiffness and their positions are arranged to simulate the torsional stiffness.

[0037] As Figure 1 shown, taking the wind tunnel ground 12 as the 0m elevation, the wind tunnel chassis 8 is 0.3m below the wind tunnel ground 12; the top surface of the pedestal 7 is lower than the wind tunnel ground 12, and the elevations of the connection between the upper structure 3 and the pile cap 11, the upper surface of the cover plate 13 and the wind tunnel ground 12 are the same; while realizing the bottom elevation of the upper structure is 0m, it can also prevent the upper structure from colliding with the wind tunnel ground when vibrating.

[0038] The wind tunnel chassis 8 can rotate to realize the simulation under different wind direction angles. Embodiment

[0039] Now, taking a certain wind tunnel test device and test process as an example to illustrate the usage method of this device.

[0040] As Figures 1 to 4 shown, the test process is as follows:

[0041] 1) Place the pedestal 7 on the 3.5m diameter wind tunnel chassis 8 of a certain ZD-1 building wind tunnel, and then place a model outer frame 1 without a lid on the pedestal 7.

[0042] 2) First establish a finite element model of soil-pile-cap in the ABAQUS finite element software, and then conduct load analysis to obtain the stiffness of the finite element model in 6 directions. Then, through the conversion of the model scale ratio, the actual spring stiffness is obtained, and appropriate compression springs 4 and tension springs 5 are selected according to the translational stiffness and their positions are arranged to simulate the torsional stiffness.

[0043] 3) Place eight compression springs 4 at the position of the round table 10 on the ground of the model outer frame 1, and then place the rigid mass block 2 on the compression springs 4. Hang six tension springs 5 on the hooks 9 on the four sides around the rigid mass block 2 respectively, and the tension springs 5 are connected to the model outer frame 1 through the hook plates 6; provide working tension for the tension springs 5 by adjusting the positions of the hook plates 6. Place eight compression springs 4 on the round table 10 on the upper surface of the rigid mass block 2, cover the ceiling cover of the model outer frame 1 and fix it after aligning the positions.

[0044] 4) Cover the cover plate 13 to make it flush with the wind tunnel ground 12, and install the upper structure 3 on the top of the bearing platform 11.

[0045] The above specific embodiments are used to illustrate the present invention, rather than to limit the present invention. Any modifications and changes made within the spirit and scope of the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure, characterized in that: It includes an outer frame of the model (1), a rigid mass block (2), an upper structure (3), a compression spring (4), a tension spring (5), a hook plate (6), a base (7), a wind tunnel chassis (8), a hook (9), a frustum (10), a bearing platform (11), and a cover plate (13); the outer frame of the model (1) is connected to the rotatable wind tunnel chassis (8) through the base (7), the rigid mass block (2) is arranged inside the outer frame of the model (1), and the rigid mass block (2) is connected to the outer frame of the model (1) through the compression spring (4) and the tension spring (5); the rigid mass block (2) bears the upper structure (3) through the bearing platform (11); the cover plate (13) is located above the outer frame of the model (1) and fixed to the wind tunnel floor (12); the upper surface of the cover plate (13) is flush with the wind tunnel floor (12); the upper structure (3) is located above the cover plate (13), and the bearing platform (11) movably passes through the middle hole of the cover plate (13); the bottom end of the bearing platform (11) is fixedly connected to the upper surface of the rigid mass block (2), and the top end of the bearing platform (11) is fixedly connected to the bottom end of the upper structure (3). The outer frame of the model (1) is fixed on the base (7), and the base (7) is fixed on the wind tunnel chassis (8). M hooks (9) are arranged on each of the four surrounding vertical surfaces of the rigid mass block (2); hook plates (6) are arranged on the four surrounding inner wall surfaces of the outer frame of the model (1), and the hook plates (6) are connected to the hooks (9) through the tension springs (5). The top and bottom surfaces of the rigid mass block (2) are elastically connected to the ceiling and floor of the outer frame of the model (1) through their respective compression springs (4), and the surrounding side surfaces of the rigid mass block (2) are elastically connected to the surrounding inner walls of the outer frame of the model (1) through their respective tension springs (5).

2. The wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure according to claim 1, characterized in that: N frustums (10) are arranged on the upper and lower surfaces of the rigid mass block (2) respectively; N frustums (10) are arranged at the middle positions between the ceiling and the floor inside the outer frame of the model (1); in the vertical direction, the frustums (10) on the ceiling of the outer frame of the model (1) correspond to the frustums (10) on the upper surface of the rigid mass block (2) one by one, the frustums (10) on the floor of the outer frame of the model (1) correspond to the frustums (10) on the lower surface of the rigid mass block (2) one by one, and the corresponding frustums (10) are connected by compression springs (4).

3. The wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure according to claim 2, characterized in that: The number of hooks M, the number of frustums N, the stiffness of the compression spring (4), and the stiffness of the tension spring (5) are obtained through finite element simulation and scale theory calculation.

4. The wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure according to claim 1, characterized in that: The top surface of the base (7) is lower than the wind tunnel floor (12), and the elevation of the connection between the upper structure (3) and the bearing platform (11), the upper surface of the cover plate (13), and the wind tunnel floor (12) are at the same level.

5. The application of the wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure according to claim 1, characterized in that: The device is used to simulate a single bearing platform foundation or a multi-bearing platform foundation.

6. The application of the wind tunnel test device for simulating the interaction of soil - pile - cap - superstructure according to claim 1, characterized in that: The device is used to simulate a pile-supported platform structure or a foundation without piles.

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