Multi-layer multi-point loading device for static test of open-web truss structure

Abstract

The invention relates to the technical field of engineering structure tests, and provides a multi-layer multi-point loading device for a static test of an open-web truss structure, which comprises a vertical guide loading stand column, horizontal distribution beams, a tension-compression conversion assembly and an anti-pulling ground beam, the horizontal distribution beams are respectively arranged at intervals along the vertical direction, one end of each horizontal distribution beam is vertically and fixedly connected with the vertical guide loading stand column, and the other end of each horizontal distribution beam is vertically and fixedly connected with the anti-pulling ground beam; one end of the vertical load guide stand column is arranged on the uplift ground beam, the other end of the vertical load guide stand column is arranged on each loading point and provided with a pressure sensing assembly, and the tension-compression conversion assembly is arranged between the bottom end of the vertical load guide stand column and the uplift ground beam and used for applying vertically-downward loading force. And when the jack applies pressure and force, the movable frame is extruded and the vertical load guide stand columns are driven to synchronously move downwards. According to the invention, a plurality of linkage jacks can be used as independent force application sources, and the static force loading test of multi-layer multi-point synchronous loading of the open-web truss structure can be efficiently and accurately carried out in a reliable control and simple and convenient operation manner.

Description

Technical Field

[0001] This invention relates to the field of engineering structure testing technology, and in particular to a multi-layer, multi-point loading device for static testing of hollow truss structures. Background Technology

[0002] In the field of civil engineering and construction, open-web truss structures are a special type of truss commonly found in large-span buildings, transfer floor structures, and complex stress systems. These structures typically consist of a top chord, a bottom chord, and straight web members, with all diagonal web members removed internally, forming a rigid frame system composed of multiple rectangular open grids. In actual engineering, floor loads are transferred through the frame system to the chords and node areas of the rectangular grids, and bending moments and shear forces are transferred through the rigid nodes. Therefore, when studying the static performance of open-web truss structures, it is often necessary to apply multi-layered, multi-point loads at the chord locations using loading devices to simulate the stress state of the structure under uniformly distributed vertical loads on each floor.

[0003] Existing structural static test loading methods mainly include the following categories: (1) Single-point loading method, which involves directly loading the truss node or beam end with a single jack. This method has a simple device, but the load is concentrated, making it impossible to achieve multi-layer and multi-point synchronous loading, and it is difficult to accurately reflect the mechanical characteristics of the open truss structure under uniformly distributed load.

[0004] (2) Sandbag or counterweight loading method, which is to form an approximately uniform load by stacking heavy objects. This method is intuitive to operate, but the load size is difficult to control precisely, the loading and unloading process is cumbersome, and it is difficult to achieve multi-layer simultaneous and uniform loading.

[0005] (3) Hydraulic system loading method, which involves applying vertical force simultaneously through multiple hydraulic cylinders. This method can achieve multi-point loading to a certain extent, but the system is complex, costly, and requires high synchronization control of multiple cylinders, making operation and maintenance difficult.

[0006] In summary, existing loading methods generally suffer from the following shortcomings: First, it is difficult to achieve synchronous and uniform application of multi-layer, multi-point loads; second, the loading accuracy is poor and the operation efficiency is low when using sandbags or counterweights; third, although hydraulic systems have multi-point loading capabilities, they are complex, costly, and the force distribution is difficult to control precisely under multi-layer vertical loading conditions. Therefore, there is an urgent need for a new type of experimental device with a reasonable structure, simple control, and the ability to achieve multi-layer, multi-point, synchronous vertical loading to meet the experimental requirements for static performance studies of open-web truss structures. Summary of the Invention To overcome the shortcomings of existing technologies in static load testing of open-web truss structures, such as poor load control accuracy, low operational efficiency, and complex system structure, this invention provides a multi-layer, multi-point loading device for static load testing of open-web truss structures. This device can achieve equivalent distribution and synchronous transmission of uniformly distributed vertical loads across multiple layers of the structure through a combination of mechanical force transmission and mechanical transmission components. It features a simple structure, flexible arrangement, high loading accuracy, and strong controllability, effectively simulating the loading state of open-web truss structures. To achieve the objectives of this invention, the following technical solution is provided: A multi-layer, multi-point loading device for static testing of a hollow truss structure includes a vertical load-directing column, a horizontal distribution beam, a tension-compression conversion assembly, and an anti-uplift beam. The vertical load-carrying columns are used to transfer the loading pressure layer by layer from bottom to top in the vertical direction; The horizontal distribution beams are spaced apart along the vertical direction, and one end of each horizontal distribution beam is perpendicularly connected to the vertical load-carrying column, while the other end is a detection end equipped with a pressure sensing component, which is arranged at each loading point. The tension-compression conversion component is connected to the bottom end of the vertical load-carrying column and is used to apply a vertically downward loading force to the vertical load-carrying column. The anti-uplift ground beam is fixedly installed in the anchorable position or in the trench of the test site and is connected to the tension-compression conversion component.

[0007] Furthermore, the horizontal distribution beam extends outward in multiple directions along the vertical load-bearing column; The horizontal distribution beam is provided with horizontal stiffening ribs at the connection with the vertical load-carrying column. The horizontal distribution beam is equipped with vertical stiffening ribs at the detection end.

[0008] Furthermore, the tension-compression conversion assembly includes a fixed frame, a movable frame, and a jack; The fixing frame is fixedly connected to the anti-uplift ground beam; The movable frame is movably connected to the fixed frame in the vertical direction, and its top is fixedly connected to the bottom end of the vertical load-bearing column. The jack is positioned between the fixed frame and the movable frame, with its top pressing against the fixed frame and its bottom pressing against the movable frame. When the jack applies pressure, it can squeeze the movable frame and pull the vertical load-bearing column to move downwards synchronously, transferring the loading force to multiple horizontal distribution beams.

[0009] Furthermore, the anti-uplift beam includes an upper flange plate, a web plate, a lower flange plate, a rib plate, and an anchor bolt enclosure plate; The upper flange plate has the fixing frame of the tension-compression conversion assembly placed on its upper surface, and the two are fixedly connected. The web is located between the upper flange and the lower flange; The rib is disposed between the upper flange, the web and the lower flange; The anchor bolt sheath is disposed between the upper flange plate and the lower flange plate, and is located at both ends of the web plate; The web, the ribs, and the anchor bolt surround are all fixedly connected to their respective surrounding plates.

[0010] Furthermore, the pressure sensing assembly includes a pressure sensor, a bearing pad, a limiting side plate, a fixing rod, an upper pad, and an abutment rib; The pressure sensor is located below the detection end in the horizontal distribution beam and is used to detect the downward loading force acting on the detection end. The bearing pad is fixedly supported below the pressure sensor and placed on the surface of the loading point component; The limiting side plate is arranged on both sides of the pressure sensor along the direction of the horizontal distribution beam and is parallel to the long side of the bearing pad. The fixing rod passes through the bearing pad in a vertical direction, and the fixing rod also includes a protruding section protruding from the bearing pad for clamping and limiting the detection end of the horizontal distribution beam; The upper pad is fitted over the top of the pressure sensor; The abutment rib is located on the top side of the upper pad and abuts and supports the bottom of the detection end of the horizontal distribution beam.

[0011] Furthermore, the fixing frame includes a vertical connecting plate and a force-bearing cover plate; The vertical connecting plate extends vertically and its bottom end is perpendicularly connected to the upper flange plate of the anti-uplift ground beam. The load-bearing cover plate is vertically connected to the top of the vertical connecting plate, and its bottom side is pressed against the top of the jack.

[0012] Furthermore, the movable frame includes a movable base plate, a mounting cover plate, and a movable connecting plate; The movable base plate is set horizontally, sleeved outside the vertical connecting plate and can slide back and forth vertically, and its top side is pressed against the bottom of the jack. The mounting cover plate is arranged parallel to and spaced apart from the movable base plate, and its top side is fixedly connected to the bottom end of the vertical load-bearing column. The movable connecting plate is arranged vertically, and its two ends are fixedly connected to the movable base plate and the mounting cover plate, respectively.

[0013] Furthermore, the movable base plate is also provided with a limiting installation strip on the top side and a vertical sliding groove that penetrates the thickness of the plate; The limiting installation stop is used to limit the bottom of the jack and to limit the pressure sensor located between the jack and the movable base plate; The vertical sliding groove is used for the movable base plate to pass through the vertical connecting plate.

[0014] Furthermore, the top side of the mounting cover is provided with a limiting mounting groove and a reinforcing retaining edge; The limiting installation groove is used to insert the vertical load-bearing column, and is configured as a groove that matches the cross-sectional shape of the vertical load-bearing column; The reinforcing flange is used to clamp and hold the vertical load-bearing column and to enhance the bending stiffness of the mounting cover plate.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By using multiple jacks in a multi-point linkage, the load-guiding column system can be driven to apply vertical pressure to multiple horizontal distribution beams, thus completing the synchronous application of multi-layer and multi-point loads. This effectively simulates the stress state of a hollow truss structure under uniformly distributed loads, improving the authenticity and representativeness of the experiment. 2. By combining mechanical and mechanical component force transmission methods with pressure sensing detection at the ends of the horizontal distribution beam, the load distribution at each loading point can be precisely controlled, thereby improving loading accuracy and the reliability of test results. 3. The main body of the device is a fish-belly beam-column frame with a built-in tension-compression conversion mechanism, consisting of load-guiding columns and multiple horizontal distribution beams. The overall layout is compact, the component connections are reliable, the force path is clear, and it has good structural stability and load transmission performance. 4. The loading and unloading process is simple to operate, and can quickly complete the application and adjustment of multi-layer loads, reducing manual operation and improving the safety and repeatability of the test process; 5. Compared with hydraulic synchronous loading systems, it has a simple structure, is easy to process, and has lower manufacturing and maintenance costs. It can also be flexibly adjusted according to different specimen sizes and number of layers. It is suitable for static loading tests of various types of open truss structures or similar structural forms and has good promotion and application value.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] Figure 1 This invention provides a schematic diagram of the overall structure of a multi-layer, multi-point loading device for static testing of a hollow truss structure. Figure 2 This invention provides a schematic diagram of a single-unit structure of a multi-layer, multi-point loading device for static testing of a hollow truss structure. Figure 3 A schematic diagram of the pressure sensing component of the multi-layer multi-point loading device for static testing of hollow truss structures provided in an embodiment of the present invention is shown. Figure 4 This diagram shows a tension-compression conversion component of a multi-layer, multi-point loading device for static testing of a hollow truss structure provided in an embodiment of the present invention. Figure 5 A schematic diagram of the anti-uplift beam structure of the multi-layer multi-point loading device for static testing of hollow truss structures provided in an embodiment of the present invention is shown.

[0018] Explanation of the labels in the diagram: 1. Vertical load-bearing column; 2. Horizontal distribution beam; 21. Pressure sensing assembly; 211. Pressure sensor; 212. Bearing pad; 213. Fixing rod; 214. Upper pad; 215. Abutment rib; 216. Limiting side plate; 22. Horizontal stiffening rib; 23. Vertical stiffening rib; 3. Tension-compression conversion assembly; 31. Fixed frame; 311. Vertical connecting plate; 312. Load-bearing cover plate; 32. Movable frame; 321. Movable base plate; 321a. Limiting installation stop bar; 321b. Vertical sliding groove; 322. Installation cover plate; 322a. Limiting installation groove; 322b. Reinforcing retaining edge; 323. Movable connecting plate; 33. Jack; 4. Anti-uplift beam; 41. Upper flange plate; 42. Web plate; 43. Lower flange plate; 44. Rib plate; 45. Anchor bolt surround plate. Detailed Implementation

[0019] To make the objectives, features, and advantages of this invention more apparent and understandable, the invention will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are merely some, not all, embodiments of the invention. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of this invention.

[0020] like Figure 1As shown, a multi-layer, multi-point loading device for static testing of a hollow truss structure according to the present invention includes a vertical load-carrying column 1, a horizontal distribution beam 2, a tension-compression conversion assembly 3, and an anti-uplift ground beam 4. The vertical load-carrying column 1 can be an I-section steel column, used to transmit loading pressure layer by layer from bottom to top in the vertical direction; the horizontal distribution beams 2 are spaced apart in the vertical direction, with one end of each horizontal distribution beam 2 vertically fixed to the vertical load-carrying column 1 and the other end serving as a detection end, arranged at each loading point, and equipped with a pressure sensing assembly 21; the tension-compression conversion assembly 3 is connected to the bottom end of the vertical load-carrying column 1, used to apply a vertically downward loading force to the vertical load-carrying column 1; the anti-uplift ground beam 4 is fixedly installed in an anchorable position or trench in the test site and connected to the tension-compression conversion assembly 3 to provide stable reaction support. In this embodiment, unless otherwise specified, the fixed connection between plates or components refers to welding.

[0021] like Figure 2 As shown, the horizontal distribution beam 2 can be designed as an I-section steel beam, extending outward in multiple different directions along the vertical load-carrying column 1 to achieve multi-layer, multi-point vertical loading based on the same vertical load-carrying column 1. Horizontal stiffening ribs 22 are welded to the connection points of the horizontal distribution beam 2 with the vertical load-carrying column 1, and vertical stiffening ribs 23 are welded to the detection end of the horizontal distribution beam 2. The horizontal stiffening ribs 22 and 23 improve the stability of the horizontal distribution beam 2 at the connection points. The load-carrying column and multiple horizontal distribution beams form a fish-belly beam-column frame, which has a compact and simple layout, clear force transmission path, excellent load-bearing stability, low manufacturing cost, and good adaptability and flexibility. Especially when there is misalignment between beams in different layers, resulting in beams and columns not being in the same vertical plane, the horizontal distribution beams 2 arranged in different directions can still apply loads to the beams of each layer through the jacks 33 at the bottom of the same vertical load-carrying column 1.

[0022] The device provided in this embodiment can be used for static loading tests on multi-story, multi-point stressed hollow truss structures, meeting the requirements for simultaneous application of multi-story concentrated loads and equivalent uniformly distributed loads. It can transfer multi-story loads along a single column using a single jack, or simultaneously control multiple jacks for coordinated loading and force control. In use, multiple loading devices can be combined to form a fish-belly beam-column frame system. The jacks in multiple tension-compression conversion components are controlled synchronously by manual or electric hydraulic pumps to achieve precise application of static loads at different heights and horizontal positions on multi-story, multi-point stressed hollow truss structures.

[0023] like Figure 3As shown, the pressure sensing assembly 21 includes a pressure sensor 211, a bearing pad 212, a limiting side plate 216, a fixing rod 213, an upper pad 214, and an abutment rib 215. The pressure sensor 211 is located below the detection end of the horizontal distribution beam 2 and is used to detect the downward loading force acting on the detection end. The bearing pad 212 is fixedly supported below the pressure sensor 211 and placed on the surface of the loading point component. The limiting side plate 216 is located on both sides of the pressure sensor 211 along the direction of the horizontal distribution beam 2 and is parallel to the long side of the bearing pad 212. The fixing rod 213 passes through the bearing pad 212 in the vertical direction and includes a protruding section protruding from the bearing pad 212 for clamping and limiting the detection end of the horizontal distribution beam. The upper pad 214 is covered on the top of the pressure sensor 211. The abutment rib 215 is located on the top side of the upper pad 214 and abuts and supports the detection end of the horizontal distribution beam below.

[0024] In this embodiment, the pressure sensor 211 is connected to the detection end via an abutment. The abutment rib 215 and the upper pad 214 work together to transmit pressure, making the pressure sensor 211 more evenly compressed and the detection results more accurate. This also provides some buffering protection for the pressure sensor 211, preventing damage from sudden loads. When the horizontal distribution beam 2 is subjected to a downward load transmitted from the vertical load-carrying column 1, the detection end presses down on the pressure sensor 211, allowing for timely acquisition of the pressure changes at the loading points of each horizontal distribution beam 2, thus enabling real-time monitoring and verification of load distribution.

[0025] like Figure 4 As shown, the tension-compression conversion assembly 3 includes a fixed frame 31, a movable frame 32, and a jack 33. The fixed frame 31 is fixedly connected to the anti-uplift beam 4; the movable frame 32 is movably connected to the fixed frame 31 in the vertical direction, and its top is fixedly connected to the bottom end of the vertical load-directing column 1; the jack 33 is disposed between the fixed frame 31 and the movable frame 32, and its top is pressed against the fixed frame 31, and its bottom is squeezed against the movable frame 32; when the jack 33 applies pressure, it can squeeze the movable frame 32 and pull the vertical load-directing column 1 to move downwards synchronously, distributing the loading force to multiple horizontal distribution beams 2.

[0026] Specifically, the fixing frame 31 includes a vertical connecting plate 311 and a load-bearing cover plate 312. The vertical connecting plate 311 is arranged vertically, and its bottom end is perpendicularly connected to the upper flange plate 41 of the anti-uplift beam 4. The load-bearing cover plate 312 is perpendicularly connected to the top end of the vertical connecting plate 311, and its bottom side is pressed against the top of the jack 33. In this embodiment, two vertical connecting plates 311 are arranged in parallel at intervals, forming a closed U-shaped fixing frame 31 with the anti-uplift beam 4 and the load-bearing cover plate 312, which can ensure the fixed stability and reliability of the fixing frame 31. The bottom side of the load-bearing cover plate 312 can be pressed against by the top of the jack 33. The fixedly installed load-bearing cover plate 312 can stably provide a downward reaction force to the jack 33, and then act downward on the movable frame 32.

[0027] Specifically, the movable frame 32 includes a movable base plate 321, a mounting cover plate 322, and a movable connecting plate 323. The movable base plate 321 is horizontally fitted onto the outside of the vertical connecting plate 311 and can slide back and forth vertically, with its top side pressing against the bottom of the jack 33. The mounting cover plate 322 is parallel to and spaced apart from the movable base plate 321, with its top side fixedly connected to the bottom end of the vertical load-guiding column 1. The movable connecting plate 323 is vertically arranged, with both ends fixedly connected to the movable base plate 321 and the mounting cover plate 322, respectively. In this embodiment, the top side of the movable base plate 321 presses against the bottom of the jack 33. When the jack 33 applies pressure to the movable base plate 321, it can drive the movable base plate 321 to slide downwards, and the movable connecting plate 323 pulls the mounting cover plate 322 and the vertical load-guiding column 1 downwards synchronously. Specifically, the movable base plate 321 is also provided with a limiting installation bar 321a on the top side and a vertical sliding groove 321b that penetrates the plate thickness. The limiting installation bar 321a is used to limit the bottom of the jack 33 and to limit the pressure sensor located between the jack 33 and the movable base plate 321. The vertical sliding groove 321b is used for the movable base plate 321 to pass through the vertical connecting plate 311. The top side of the mounting cover plate 322 is provided with a limiting installation groove 322a and a reinforcing flange 322b. The limiting installation groove 322a is used to insert the vertical load-carrying column 1 and is set as a groove that matches the cross-sectional shape of the vertical load-carrying column 1. The reinforcing flange 322b is used to clamp and block the vertical load-carrying column 1 and to strengthen the bending stiffness of the mounting cover plate 322.

[0028] In this embodiment, the limiting mounting strips 321a are specifically configured as two arc-shaped protrusions along the same circumferential diameter. Through the "wrapping" effect of the two limiting mounting strips 321a, the bottom of the jack 33 can be stably limited and installed in the movable base plate 321. At the same time, the pressure sensor can be set at the bottom end of the jack 33, which together are fitted and limited in the "wrapping area" formed by the limiting mounting strips 321a. The vertical sliding grooves 321b are provided with two parallel ones on the movable base plate 321, which facilitates the movable base plate 321 of the movable frame 32 to slide up and down as a whole under the action of the jack 33, and allows the vertical connecting plate 311 of the fixed frame 31 to pass through the movable base plate 321 and connect to the anti-uplift beam 4. The limiting installation groove 322a can be set as an I-shaped groove that matches the cross-sectional shape of the vertical load-guiding column 1. The bottom end of the vertical load-guiding column 1 can be inserted into the limiting installation groove 322a to achieve positioning and pre-installation with the installation cover plate 322. Then, the installation cover plate 322 and the vertical load-guiding column 1 can be fixedly connected by riveting, bolting or welding. When jack 33 applies force, its top end pushes upward against fixed frame 31, and its bottom end squeezes downward against movable frame 32. Fixed frame 31 is welded to the upper flange plate 41 of anti-uplift beam 4, preventing overall slippage. The pressure generated by jack 33 is applied downward to movable frame 32, causing movable frame 32 and vertical load-directing column 1 to slide vertically together. When vertical load-directing column 1 moves downward, multiple horizontal distribution beams 2 fixedly connected to its side wall also shift downward, causing each horizontal distribution beam 2 to exert downward pressure on the loading point at the detection end. Thus, the upward thrust generated by jack 33 is converted into downward compressive force on vertical load-directing column 1 through the reverse transmission between fixed frame 31 and movable frame 32. Vertical load-directing column 1 further distributes this pressure to each horizontal distribution beam 2, achieving multi-point loading of multi-layer beams by a single jack 33. The device has a compact structure and a clear force transmission path. It has the advantages of high operating efficiency, good load control accuracy, excellent structural stability and low manufacturing cost. It is suitable for various engineering scenarios such as open truss structures and similar conversion structures, and provides an efficient and reliable static test loading method for studying the stress performance of such structural systems.

[0029] During the progressive loading process, the tension-compression conversion component 3 relies on the progressive jacking of jack 33 to achieve different load conditions. To ensure loading accuracy, a pressure sensor can be placed below jack 33 to monitor the jacking force in real time. When the predetermined load condition is reached, it is necessary to wait for the loading device to complete the force redistribution. Due to factors such as welds in the loading device, the jacking force may temporarily drop. At this time, the force value of jack 33 should be adjusted by the oil pump until the pressure sensor reading stabilizes, at which point the application of that load level can be considered complete.

[0030] like Figure 5As shown, the anti-uplift ground beam 4 includes an upper flange plate 41, a web plate 42, a lower flange plate 43, a rib plate 44, and an anchor bolt enclosure plate 45. A fixing frame 31 of the tension-compression conversion assembly 3 is placed on the upper surface of the upper flange plate 41, and the two are fixedly connected; the web plate 42 is located between the upper flange plate 41 and the lower flange plate 43; the rib plate 44 is located between the upper flange plate 41, the web plate 42, and the lower flange plate 43; the anchor bolt enclosure plate 45 is located between the upper flange plate 41 and the lower flange plate 43, and is located at both ends of the web plate 42; the web plate 42, the rib plate 44, and the anchor bolt enclosure plate 45 are all fixedly connected to their respective peripheral plates.

[0031] In this embodiment, after the upper flange plate 41, web plate 42 and lower flange plate 43 are welded, rib plates 44 are arranged at regular intervals along the length of the anti-uplift beam 4 to enhance the local stress stability of the anti-uplift beam 4. At the same time, anchor holes of appropriate size are provided at the vertically corresponding positions at both ends of the upper flange plate 41 and lower flange plate 43 of the anti-uplift beam 4 so that the ground anchor bolts can pass through the anti-uplift beam and be fixed in the anchoring position of the test site or in the trench. The anchor bolt enclosure plate 45 set at this location can enhance the local stress stability of the anchor bolts of the anti-uplift beam 4.

[0032] This invention presents a multi-layer, multi-point synchronous loading device for static testing of open-web truss structures. A load-guiding system driven by multi-point linkage control jacks is established, achieving multi-layer, multi-point vertical loading through a three-dimensional distribution mechanism. A fish-belly-shaped beam-column frame with built-in tension-compression conversion components 3 is constructed, forming a simple, stiffness-controllable, and clearly defined force transmission system. By comprehensively considering the mechanical coordination of multi-layer load synchronous transmission and the structural stability along the loading path, a complete static loading device for open-web truss structures is formed.

[0033] Using this device, experiments can achieve synchronous transfer and accurate distribution of vertical static loads, meeting the requirements of multi-point and multi-layer loading, and reproducing the loading state of open-web truss structures under different distributed loads. Through the built-in pressure monitoring and distribution control mechanism, real-time control and precise adjustment of the loading process can be achieved. The experimental results can be directly used for the stress performance analysis and design verification of open-web truss structures and similar transfer structures, supplementing the shortcomings of existing experimental loading techniques. It provides a simple and reliable experimental loading method for the stress performance research and engineering design of this type of structure, and has good application and promotion value.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] The above are merely specific embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multi-layer, multi-point loading device for static testing of a hollow truss structure, characterized in that, include: Vertical load-bearing columns are used to transfer loading pressure layer by layer from bottom to top in a vertical direction; Horizontal distribution beams are spaced apart along the vertical direction, with one end of each horizontal distribution beam perpendicularly connected to the vertical load-carrying column and the other end serving as a detection end equipped with a pressure sensing component, which is arranged at each loading point. The tension-compression conversion assembly is connected to the bottom end of the vertical load-carrying column and is used to apply a vertically downward loading force to the vertical load-carrying column. The anti-uplift ground beam is fixedly installed in the test site at the anchorable position or in the trench, and is connected to the tension-compression conversion component.

2. The multi-layer, multi-point loading device for static testing of hollow truss structures according to claim 1, characterized in that, The horizontal distribution beam extends outward in multiple directions along the vertical load-bearing columns perpendicular to the horizontal distribution beam. The horizontal distribution beam is provided with horizontal stiffening ribs at the connection with the vertical load-carrying column. The horizontal distribution beam is equipped with vertical stiffening ribs at the detection end.

3. The multi-layer, multi-point loading device for static testing of hollow truss structures according to claim 1, characterized in that, The tension-compression conversion assembly includes a fixed frame, a movable frame, and a jack; The fixing frame is fixedly connected to the anti-uplift ground beam; The movable frame is movably connected to the fixed frame in the vertical direction, and its top is fixedly connected to the bottom end of the vertical load-bearing column. The jack is positioned between the fixed frame and the movable frame, with its top pressing against the fixed frame and its bottom pressing against the movable frame. When the jack applies pressure, it can squeeze the movable frame and pull the vertical load-bearing column to move downwards synchronously, transferring the loading force to multiple horizontal distribution beams.

4. The multi-layer, multi-point loading device for static testing of hollow truss structures according to claim 3, characterized in that, The anti-uplift beam includes an upper flange plate, a web plate, a lower flange plate, a rib plate, and an anchor bolt enclosure plate; The upper flange plate has the fixing frame of the tension-compression conversion assembly placed on its upper surface, and the two are fixedly connected. The web is located between the upper flange and the lower flange; The rib is disposed between the upper flange, the web and the lower flange; The anchor bolt sheath is disposed between the upper flange plate and the lower flange plate, and is located at both ends of the web plate; The web, the ribs, and the anchor bolt surround are all fixedly connected to their respective surrounding plates.

5. The multi-layer, multi-point loading device for static testing of hollow truss structures according to claim 2, characterized in that, The pressure sensing component includes: A pressure sensor is disposed below the detection end in the horizontal distribution beam and is used to detect the downward loading force acting on the detection end. A bearing pad is fixedly supported below the pressure sensor and placed on the surface of the loading point component; Limiting side plates are arranged on both sides of the pressure sensor along the direction of the horizontal distribution beam and are parallel to the long side of the bearing pad. A fixing rod is inserted vertically through the bearing pad and includes a protruding section protruding from the bearing pad for clamping and limiting the detection end of the horizontal distribution beam; An upper pad is fitted over the top of the pressure sensor; The abutment rib is provided on the top side of the upper pad and abuts and supports the bottom of the detection end of the horizontal distribution beam.

6. The multi-layer, multi-point loading device for static testing of hollow truss structures according to claim 4, characterized in that, The fixing frame includes: A vertical connecting plate extends vertically and its bottom end is perpendicularly connected to the upper flange plate of the anti-uplift ground beam. The load-bearing cover plate is vertically connected to the top of the vertical connecting plate, and its bottom side is pressed against the top of the jack.

7. The multi-layer, multi-point loading device for static testing of hollow truss structures according to claim 6, characterized in that, The movable frame includes: The movable base plate is set horizontally, sleeved on the outside of the vertical connecting plate and can slide back and forth vertically, and its top side is pressed against the bottom of the jack. Install a cover plate, which is parallel and spaced apart from the movable base plate, and its top side is fixedly connected to the bottom end of the vertical load-bearing column; The movable connecting plate is set vertically, and its two ends are fixedly connected to the movable base plate and the mounting cover plate, respectively.

8. The multi-layer, multi-point loading device for static testing of hollow truss structures according to claim 7, characterized in that, The movable base plate is equipped with a limiting installation strip on the top side and a vertical sliding groove that penetrates the plate thickness. The limiting installation stop is used to limit the bottom of the jack and to limit the installation of the pressure sensor located between the jack and the movable base plate. The vertical sliding groove is used for the movable base plate to pass through the vertical connecting plate; The top side of the mounting cover is provided with a limiting mounting groove and a reinforcing retaining edge. The limiting installation groove is used to insert the vertical load-guiding column, and is configured as a groove adapted to the cross-sectional shape of the vertical load-guiding column. The reinforcing flange is used to clamp and hold the vertical load-bearing column and to enhance the bending stiffness of the mounting cover plate.

Images