Tensioning-free beam string structure and construction method thereof

Abstract

According to the tensioning-free beam string structure and the construction method, a plurality of combined supporting rods are arranged in the middle of the lower surface of a steel pipe beam, one ends of the combined supporting rods are fixedly connected with the lower surface of the steel pipe beam, inhaul cable supports are arranged at the two ends of the lower surface of the steel pipe beam, and the ends of inhaul cables are connected with the inhaul cable supports correspondingly; the inhaul cable is in lap joint with the other ends of the multiple combined supporting rods. The combined supporting rod is composed of an upper supporting rod body, a sleeve connecting joint and a lower supporting rod body. One end of the upper supporting rod is fixedly connected with the lower surface of the steel pipe beam, the other end of the upper supporting rod is connected with one end of the lower supporting rod through the sleeve connecting joint, and a clamping groove is formed in the other end of the lower supporting rod and used for containing the inhaul cable. The problems of difficult construction and high production cost caused by the fact that a traditional beam string structure needs to be pre-tensioned in a specific factory building and equipment are solved, the pre-tensioning-free mode is achieved through the combined supporting rods, the construction process is simplified, inhaul cable adjustment can be conducted on site, and the construction difficulty and cost are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of steel structures, and particularly relates to a cable-stayed beam structure without tensioning and a construction method thereof. Background Art

[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.

[0003] The cable-stayed beam structure is a hybrid structure system formed by a rigid upper chord, flexible cables, and intermediate struts. The main feature of this structure is the use of prestress to control the internal forces and deformations of the beam, reducing the load on the lower structure and foundation. Moreover, it is simple and convenient for manufacturing, transportation, and construction, so it has good application prospects.

[0004] The existing construction methods for cable-stayed beams usually include steps such as cable clamp installation, cable hanging, prestress application, and support frame removal. Among them, the process of prestress application is generally completed by tensioning. The method of applying prestress by tensioning has extremely high requirements for the control of the tension force and the tensioning sequence, and it is often difficult to accurately control the tensioning quality. The existing tensioning methods also require specific workshops and equipment, and after tensioning, they are transported to the construction site, resulting in relatively high production and transportation costs. Especially for large cable-stayed beam structures, their transportation not only requires large transportation tools, but also special means of protection during transportation. Therefore, the existing tensioning methods for cable-stayed beams are time-consuming and laborious, and the quality is difficult to control. Summary of the Invention

[0005] Aiming at the above problems, the present invention provides a cable-stayed beam structure without tensioning, which solves the problems of difficult construction and high production costs caused by the need for pre-tensioning in a specific workshop and equipment for traditional cable-stayed beam structures. The form of realizing tensioning without pre-tensioning through the combined struts simplifies the construction process, and the adjustment of the cables can be realized on-site, reducing the construction difficulty and cost.

[0006] To achieve the above object, the present invention is realized through the following technical solutions:

[0007] In a first aspect, the present invention provides a cable-stayed beam structure without tensioning, including: a steel pipe beam, cables, combined struts, and cable supports. A plurality of the combined struts are arranged in the middle of the lower surface of the steel pipe beam. One end of the combined strut is fixedly connected to the lower surface of the steel pipe beam. Cable supports are arranged at both ends of the lower surface of the steel pipe beam. The ends of the cables are respectively connected to the cable supports, and the cables are respectively lapped with the other ends of the plurality of combined struts;

[0008] The combined strut is composed of an upper strut, a sleeve connecting joint, and a lower strut; one end of the upper strut is fixedly connected to the lower surface of the steel pipe beam, and the other end is connected to one end of the lower strut through the sleeve connecting joint. A clamping groove is provided at the other end of the lower strut for placing the cable.

[0009] Further, the sleeve connecting joint includes two thread conversion heads, an expansion rod, and a threaded sleeve; the thread conversion head has a stepped shaft structure with threads provided on the side, and is divided into a first thread section and a second thread section. The shaft diameter of the first thread section is smaller than that of the second thread section, and a blind hole is provided in the core of the second thread section for installing the aluminum alloy expansion rod; internal threads are provided in the threaded sleeve for mating with the second thread section;

[0010] The first thread section of one of the thread conversion heads is in mating connection with the upper strut internal thread at the end of the upper strut, the second thread section is connected to one end of the threaded sleeve, and one end of the expansion rod is inserted into the blind hole; the first thread section of the other thread conversion head is in mating connection with the lower strut internal thread at the end of the lower strut, the second thread section is connected to one end of the threaded sleeve, and the other end of the expansion rod is inserted into the blind hole.

[0011] Further, the upper strut includes a threaded steel pipe, and a connection end plate is fixedly provided at one end of the threaded steel pipe away from the installation of the thread conversion head. The connection end plate is connected to the upper strut by welding, and an included angle with a set angle is provided between the normal line of the connection end plate and the axis of the upper strut.

[0012] Further, the expansion rod is made of aluminum alloy, and the formula for the length deformation of the expansion rod is as follows: ΔL = αL0(T + 195.79°C)

[0013] Where α is the linear expansion coefficient of the aluminum alloy, T is the temperature for heating the aluminum alloy expansion rod during construction, and L0 is the length of the aluminum alloy expansion rod at the ambient temperature at the construction site.

[0014] Further, the cable support includes a support end plate and two relatively arranged support connecting plates. A through hole is provided in the middle of the support connecting plates. The end of the cable is a cable connecting plate, and the diameter of the through hole on the cable connecting plate is the same as that of the through hole of the support connecting plate of the cable support.

[0015] Further, the steel pipe beam is respectively connected to the cable support and the connection end plate through connecting fasteners.

[0016] In a second aspect, the present invention also provides a construction method for a cable-supported beam structure without tensioning, including the following steps:

[0017] S1: Connect the upper strut and the cable support to the steel pipe beam through connecting fasteners, and hinge the cable to the cable support through a shear member; pre - sleeve the threaded sleeve onto the lower strut, place the lower strut in a position corresponding to the upper strut, place the cable into the card slot of the lower strut, and install threaded adapters on the upper strut and the lower strut respectively;

[0018] S2: Place the pre - frozen expansion rod into the gap between the upper strut and the lower strut, so that the upper strut, the lower strut and the expansion rod are on the same axis, and let the expansion rod naturally warm up and elongate or heat and elongate, press the cable to apply a pre - tightening force. If there are multiple combined struts in the beam string structure, all combined struts need to be operated simultaneously;

[0019] S3: Monitor the strain of the cable. When the strain of the cable reaches a predetermined value, stop heating the expansion rod;

[0020] S4: Rotate the threaded sleeve and connect it to the upper and lower threaded adapters to complete the assembly of the beam string structure.

[0021] Further, in S2, the expansion rod is frozen in liquid nitrogen before construction.

[0022] Further, the shaft diameter of the first threaded section and the hole diameter of the blind hole are both smaller than the shaft diameter of the second threaded section, and the expansion rod and the blind hole are in transitional fit.

[0023] Further, when connecting the cable to the cable support in S1, place the cable connecting plate between the two support connecting plates, make the three hole positions correspond, and then insert the shear member.

[0024] Compared with the prior art, the advantages and positive effects of the present invention are:

[0025] The assembled combined strut of the present invention adopts an assembled design and is composed of an upper strut, a sleeve connecting section and a lower strut. It can realize on - site cable positioning and tension control, improving construction efficiency and structural stability: the lower strut is provided with a card slot that precisely matches the cable, which can effectively prevent the cable from displacing during the stress process and improve structural stability. At the same time, the sleeve connecting section can automatically adjust the cable tension during installation. When the appropriate tension is reached, the distance between the upper and lower struts is fixed. This solves the problem that it is difficult to control the cable tension. Compared with the traditional construction process that requires repeated measurement and adjustment of the cable tension, the construction efficiency is greatly improved. For large - span space structures, compared with the traditional beam string structure, its non - tensioning characteristic greatly simplifies the construction process and reduces the construction difficulty and cost.

[0026] The beam string structure of the present invention utilizes the thermal expansion and contraction characteristics of the expansion rod made of aluminum alloy to replace the complex tensioning process of the traditional beam string structure. By heating the expansion rod during construction, it elongates and compresses the cable, applying a pre-tightening force. This structure avoids the dependence on tensioning equipment during the traditional tensioning process, as well as the problems of uneven tensioning and difficulty in precisely controlling the tensioning force, greatly simplifies the construction process, and reduces the construction difficulty and cost. The construction unit does not need to invest a large amount of funds to purchase tensioning equipment, nor does it need to arrange professional technicians for tensioning operations, reducing labor and equipment costs.

[0027] The upper strut of the present invention is connected to the steel pipe beam by welding a connecting end plate, and the weld seam is strictly inspected by flaw detection to ensure the welding quality; the cable and the cable support are hinged by inserting shear members into the corresponding through holes; the steel pipe beam is connected to the cable support and the connecting end plate by high-strength bolts, and the tightening torque of the bolts is monitored in real time. These connection methods effectively solve the problem of unreliable connection of structural components, ensure the safety and stability of the structure during use, and extend the service life of the structure.

[0028] The construction process monitoring system of the beam string structure of the present invention solves the problem that it is difficult to guarantee the construction quality and ensures that the structure meets the design requirements: during the construction process, a temperature sensor is used to monitor the temperature of the expansion rod in real time to control the heating speed; a strain gauge or a fiber Bragg grating sensor is used to monitor the strain of the cable, and the monitoring data is analyzed in real time. This construction process monitoring system solves the problem that it is difficult to guarantee the construction quality, ensures that the pre-tightening force of the cable and the stress state of the structure meet the design requirements, and avoids potential structural safety hazards caused by improper construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings forming a part of this specification are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions thereof are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0030] Figure 1 It is the overall structure diagram of the beam string of the present invention;

[0031] Figure 2 It is the schematic diagram of the cable support structure of the beam string of the present invention;

[0032] Figure 3 It is the schematic diagram of the combined strut structure of the beam string of the present invention;

[0033] Figure 4 It is the schematic diagram of the upper strut structure of the present invention;

[0034] Figure 5 It is the schematic diagram of the thread adapter structure of the present invention;

[0035] Figure 6 It is the schematic diagram of the lower strut structure of the present invention;

[0036] Figure 7 This is a schematic diagram of the construction and installation process of the beam string structure of the present invention.

[0037] In the figure: 1. Steel pipe beam; 2. Cable; 21. Cable connection plate; 3. Upper strut; 31. Threaded steel pipe; 311. Internal thread of the upper strut; 32. Connection end plate; 4. Sleeve connection joint; 41. Thread conversion head; 411. First thread section; 412. Second thread section; 42. Expansion rod; 43. Threaded sleeve; 5. Lower strut; 51. Internal thread of the lower strut; 52. Card slot; 6. Connection fastener; 7. Cable support; 71. Support end plate; 72. Support connection plate. Detailed implementation mode

[0038] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0039] It should be noted that the terms used herein are only for describing the specific implementation mode and are not intended to limit the exemplary implementation mode according to the present invention. As used herein, unless the present invention clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations;

[0040] Embodiment 1

[0041] This embodiment provides a beam string structure without tensioning, which has a wide application prospect in the construction field, especially suitable for large-span space structures. Compared with the traditional beam string structure, its characteristic of no tensioning greatly simplifies the construction process and reduces the construction difficulty and cost. As Figures 1-7 shown, it includes: a steel pipe beam 1, a cable 2, a combined strut and a cable support 7. A plurality of the combined struts are arranged in the middle of the lower surface of the steel pipe beam 1. One end of the combined strut is fixedly connected to the lower surface of the steel pipe beam 1. Cable supports 7 are arranged at both ends of the lower surface of the steel pipe beam 1. The end parts of the cable 2 are respectively connected to the cable supports 7, and the cable 2 is respectively lapped with the other ends of the plurality of combined struts;

[0042] Specifically, the steel pipe beam 1 serves as the main load-bearing member of the beam string structure, and a plurality of combined struts are arranged in the middle of its lower surface at specific intervals. One end of each combined strut is firmly fixed to the lower surface of the steel pipe beam 1 by means of welding or high-strength bolts, etc., thereby providing stable vertical support for the entire structure. At both ends of the lower surface of the steel pipe beam 1, cable supports 7 are provided, and the end parts of the cables 2 are respectively connected to the cable supports 7. The cables 2 are respectively lapped with the other ends of the plurality of combined struts, and the three work together to effectively balance the internal forces of the structure.

[0043] The combined strut is composed of an upper strut 3, a sleeve connection joint 4, and a lower strut 5; one end of the upper strut 3 is fixedly connected to the lower surface of the steel pipe beam 1, and the other end is connected to one end of the lower strut 5 through the sleeve connection joint 4. A clamping groove 52 is provided at the other end of the lower strut 5 for placing the cable 2.

[0044] Specifically, the combined strut adopts a unique assembled design and is composed of an upper strut 3, a sleeve connection joint 4, and a lower strut 5. One end of the upper strut 3 is fixedly connected to the lower surface of the steel pipe beam 1, and the other end is connected to one end of the lower strut 5 through the sleeve connection joint 4. When installing, the sleeve connection joint 4 directly and automatically adjusts the tension of the cable 2 until the appropriate tension is reached, and then the distance between the upper strut 3 and the lower strut 5 is fixed. A clamping groove 52 is provided at the other end of the lower strut 5, and the size of the clamping groove 52 is precisely matched with the cable 2 for stably placing the cable 2 to prevent the cable 2 from displacing during the stress process.

[0045] Furthermore, the sleeve connection joint 4, as the core connection component of the combined strut, includes two threaded conversion heads 41, an expansion rod 42, and a threaded sleeve 43; the threaded conversion head has a stepped shaft structure and is provided with threads on the side, which is divided into a first threaded section 411 and a second threaded section 412. The shaft diameter of the first threaded section 411 is smaller than that of the second threaded section 412, and a blind hole is provided in the core of the second threaded section 412 for installing the aluminum alloy expansion rod 42; internal threads are provided in the threaded sleeve 43 for cooperating with the second threaded section 412;

[0046] One end of the first threaded section 411 of one of the threaded conversion heads 41 is connected to the upper strut internal thread 311 at the end of the upper strut 3, the second threaded section 412 is connected to one end of the threaded sleeve 43, and one end of the expansion rod 42 is inserted into the blind hole; one end of the first threaded section 411 of the other threaded conversion head 41 is connected to the lower strut internal thread 51 at the end of the lower strut 5, the second threaded section 412 is connected to one end of the threaded sleeve 43, and the other end of the expansion rod 42 is inserted into the blind hole, thereby realizing the reliable connection of the upper strut 3, the lower strut 5, and the expansion rod 42.

[0047] Further, the upper strut 3 includes a threaded steel pipe 31, and a connection end plate 32 is fixedly provided at one end of the threaded steel pipe 31 away from the installation of the threaded adapter 41. The connection end plate 32 is connected to the upper strut 3 by welding, and a set - angle included angle is provided between the normal line of the connection end plate 32 and the axis of the upper strut 3. Specifically, the connection end plate 32 is connected to the upper strut 3 by welding, and the weld seam needs to be strictly inspected for flaw detection to ensure the welding quality. A set - angle included angle is provided between the normal line of the connection end plate 32 and the axis of the upper strut 3, and this included angle is determined according to the structural stress characteristics and design requirements to ensure that the upper strut 3 can form the best stress angle with the steel pipe beam 1 after installation.

[0048] Further, the expansion rod 42 is made of aluminum alloy with a large coefficient of linear expansion and high strength, which enables the expansion rod 42 to produce a significant length change when the temperature changes, thereby providing a pre - tightening force for the cable 2. The formula for the length deformation of the expansion rod 42 is as follows:

[0049] ΔL = αL0(T + 195.79℃)

[0050] Where α is the coefficient of linear expansion of the aluminum alloy, T is the temperature at which the aluminum alloy expansion rod 42 is heated during construction, and L0 is the length of the aluminum alloy expansion rod 42 at the on - site atmospheric temperature during construction.

[0051] Further, the cable support 7 includes a support end plate 71 and two oppositely arranged support connection plates 72. A through - hole is provided in the middle of the support connection plates 72. The end of the cable 2 is a cable connection plate 21, and the diameter of the through - hole on the cable connection plate 21 is the same as that of the through - hole of the support connection plates 72 of the cable support 7. A shear member, such as a pin shaft or a shear - resistant screw, is inserted into the through - hole on the cable connection plate 21 and the through - hole of the support connection plates 72 of the cable support 7 to achieve the hinged connection between the cable 2 and the cable support 7, ensuring that the cable 2 can rotate freely and adapt to the deformation of the structure during the stress process.

[0052] Further, the steel pipe beam 1 is connected to the cable support 7 and the connection end plate 32 respectively through connection fasteners 6. Specifically, the steel pipe beam 1 is connected to the cable support 7 and the connection end plate 32 respectively through connection fasteners 6, such as high - strength bolts, to ensure the reliability and stability of the connection. During the installation process, it is necessary to strictly operate in accordance with the design requirements and construction specifications, and monitor the tightening torque of the bolts in real time to ensure the connection quality.

[0053] Embodiment 2

[0054] This embodiment provides a construction method for a cable-strut beam structure without tensioning. By ingeniously utilizing the thermal expansion and contraction characteristics of the expansion rod 42, the tension-free installation of the cable 2 is realized, effectively shortening the construction period and improving the construction efficiency. The specific steps are as follows:

[0055] S1: Connect the upper strut 3 and the cable support 7 to the steel pipe beam 1 through the connecting fasteners 6. During the connection process, ensure that the installation positions of the upper strut 3 and the cable support 7 are accurate without error, guarantee the connection accuracy. The connecting fasteners 6 are tightened according to the tightening torque required by the design, and double-nut anti-loosening measures are adopted to prevent loosening during the construction process. Hinge the cable 2 to the cable support 7 through a shear member. Specifically, when operating, place the cable connecting plate 21 between the two support connecting plates 72, make the three opening positions accurately correspond, then insert the shear member, such as a pin shaft, and install an open pin for locking to prevent the pin shaft from falling off. Pre-sleeve the threaded sleeve 43 onto the lower strut 5, place the lower strut 5 in the position corresponding to the upper strut 3, place the cable 2 into the card slot 52 of the lower strut 5, and install threaded adapters 41 on the upper strut 3 and the lower strut 5 respectively. When installing, ensure that the threaded adapter 41 is tightly matched with the thread of the strut to avoid loosening.

[0056] S2: Before construction, place the expansion rod 42 in liquid nitrogen (-195.79 °C) for freezing to make its length contract for easy installation. When taking out the expansion rod 42, wear protective gloves to prevent frostbite. Place the pre-frozen expansion rod 42 into the gap between the upper strut 3 and the lower strut 5, so that the upper strut 3, the lower strut 5, and the expansion rod 42 are on the same axis. Let the expansion rod 42 naturally heat up and expand or be heated to expand, press the cable 2 to apply a pre-tightening force. If there are multiple combined struts in the cable-strut beam, all combined struts need to be operated simultaneously to ensure that the cable 2 is uniformly stressed. During the heating process, use a temperature sensor to monitor the temperature of the expansion rod 42 in real time and control the heating speed.

[0057] S3: Monitor the strain of the cable 2, and monitoring devices such as strain gauges or fiber Bragg grating sensors can be used. When the strain of the cable 2 reaches the predetermined value, stop heating the expansion rod 42. During the monitoring process, the monitoring data needs to be analyzed in real time to ensure that the strain of the cable 2 meets the design requirements.

[0058] S4: Rotate the threaded sleeve 43 and connect it to the upper and lower threaded adapters 41. During the rotation process, use special tools to ensure that the tightening torque of the threaded sleeve 43 meets the design requirements. After completing the connection of the threaded sleeve 43, conduct a comprehensive inspection of the entire cable-strut beam structure to ensure that all components are firmly connected without loosening. Thus, the assembly of the cable-strut beam is completed.

[0059] Further, in S2, the expansion rod 42 is frozen in liquid nitrogen (-195.79 °C) before construction.

[0060] Further, the shaft diameter of the first threaded section 411 and the hole diameter of the blind hole are both smaller than the shaft diameter of the second threaded section 412, and the expansion rod 42 and the blind hole are in transitional fit.

[0061] Further, when the cable 2 is connected to the cable support 7 in S1, the cable connection plate 21 is placed between the two support connection plates 72 so that the three opening positions correspond to each other, and then the shear member is inserted.

[0062] Although the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, it is not a limitation on the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the present invention.

Claims

1. A cable-strut beam structure without tensioning, characterized in that, Comprising: A steel pipe beam, stay cables, combined struts and stay cable supports. A plurality of the combined struts are arranged in the middle of the lower surface of the steel pipe beam. One end of the combined strut is fixedly connected to the lower surface of the steel pipe beam. Stay cable supports are arranged at both ends of the lower surface of the steel pipe beam. The end parts of the stay cables are respectively connected to the stay cable supports, and the stay cables are respectively lapped with the other ends of the plurality of combined struts; The combined strut is composed of an upper strut, a sleeve connection joint and a lower strut; one end of the upper strut is fixedly connected to the lower surface of the steel pipe beam, and the other end is connected to one end of the lower strut through the sleeve connection joint. A clamping groove is arranged at the other end of the lower strut for placing the stay cable.

2. The cable-strut beam structure without tensioning according to claim 1, wherein The sleeve connection joint includes two threaded adapter sleeves, an expansion rod and a threaded sleeve; the threaded adapter sleeve is of a stepped shaft structure and is provided with threads on the side, and is divided into a first threaded section and a second threaded section. The shaft diameter of the first threaded section is smaller than that of the second threaded section, and a blind hole is arranged in the core of the second threaded section for installing the aluminum alloy expansion rod; internal threads are arranged in the threaded sleeve for cooperating with the second threaded section; The first threaded section of one of the threaded adapter sleeves is in threaded fit connection with the upper strut internal thread at the end of the upper strut, the second threaded section is connected to one end of the threaded sleeve, and one end of the expansion rod is inserted into the blind hole; the first threaded section of the other threaded adapter sleeve is in threaded fit connection with the lower strut internal thread at the end of the lower strut, the second threaded section is connected to one end of the threaded sleeve, and the other end of the expansion rod is inserted into the blind hole.

3. The cable-supported beam structure without tensioning according to claim 1, wherein, The upper strut includes a threaded steel pipe, and a connection end plate is fixedly arranged at the end of the threaded steel pipe away from the installation of the threaded adapter sleeve. The connection end plate is connected to the upper strut by welding, and an included angle with a set angle is arranged between the normal line of the connection end plate and the axis of the upper strut.

4. The cable-strut beam structure without tensioning according to claim 2, characterized in that, The expansion rod is made of aluminum alloy, and the length deformation amount formula of the expansion rod is as follows: ΔL = αL0(T + 195.79 °C) Where α is the linear expansion coefficient of the aluminum alloy, T is the temperature for heating the aluminum alloy expansion rod during construction, and L0 is the length of the aluminum alloy expansion rod at the on-site atmospheric temperature during construction.

5. The pretension-free beam string structure according to claim 1, characterized in that, The stay cable support includes a support end plate and two relatively arranged support connection plates. A through hole is arranged in the middle of the support connection plates. The end part of the stay cable is a stay cable connection plate, and the diameter of the through hole on the stay cable connection plate is the same as that of the through hole of the support connection plate of the stay cable support.

6. The non-tensioned beam string structure according to claim 5, characterized in that The steel pipe beam is respectively connected to the stay cable support and the connection end plate through connection fasteners.

7. The construction method of a cable-supported beam structure without tensioning according to any one of claims 1-6, characterized in that, Including the following steps: S1: Connect the upper strut and the stay cable support to the steel pipe beam through connection fasteners, and hinge the stay cable to the stay cable support through a shear member; pre-sleeve the threaded sleeve onto the lower strut, place the lower strut at a position corresponding to the upper strut, place the stay cable into the clamping groove of the lower strut, and respectively install threaded adapter sleeves on the upper strut and the lower strut; S2: Place the pre-frozen expansion rod into the gap between the upper strut and the lower strut, aligning the upper strut, the lower strut, and the expansion rod on the same axis. Let the expansion rod expand naturally as it warms up or expand by heating, and apply a pre-tensioning force to the stay cable. If there are multiple combined struts in the beam string structure, the operation needs to be carried out on all combined struts simultaneously; S3: Monitor the strain of the stay cable. When the strain of the stay cable reaches a predetermined value, stop heating the expansion rod; S4: Rotate the threaded sleeve and connect it to the upper and lower threaded adapters to complete the assembly of the beam string structure.

8. The construction method of a cable-supported beam structure without tensioning as claimed in claim 7, characterized in that, In S2, the expansion rod is frozen in liquid nitrogen before construction.

9. The construction method of a cable-supported beam structure without tensioning according to claim 7, characterized in that, The shaft diameter of the first threaded section and the aperture diameter of the blind hole are both smaller than the shaft diameter of the second threaded section, and the expansion rod and the blind hole are in a transition fit.

10. The construction method of a cable-supported beam structure without tensioning as claimed in claim 7, characterized in that, When connecting the stay cable to the stay cable support in S1, place the stay cable connection plate between the two support connection plates so that the three hole positions correspond, and then insert the shear member.

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