Large-span steel-wood composite structure fixed-length cable tensioning construction method under large temperature and humidity difference environment

Abstract

The invention provides a large-span steel-wood composite structure fixed-length cable tensioning construction method suitable for a large-temperature-humidity-difference environment, and belongs to the technical field of constructional engineering. Comprising the steps of nano hydrophobic modification of wood, corrosion prevention and temperature control treatment of steel, installation of an intelligent anchorage device and a sensor network, staged dynamic tensioning construction, interface strengthening and protection and BIM model comparison and acceptance. According to the method, the mechanical response of the structure in a large temperature and humidity difference environment can be mastered in real time, data support is provided for dynamic compensation of the intelligent anchorage device, and the safety and durability of the large-span steel-wood composite structure are ensured. The construction precision, the structural life and the environmental adaptability are comprehensively improved, the problems of steel-wood deformation difference, dynamic environment compensation and long-term performance stability are solved, the method is suitable for complex engineering scenes such as gymnasiums and bridges, a reliable solution is provided for engineering of green buildings and complex climate areas, and remarkable social and economic benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of construction engineering, and specifically relates to a fixed-length cable tensioning construction method for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference. Background Art

[0002] The construction of long-span steel-timber composite structures in environments with significant temperature and humidity fluctuations presents significant challenges, particularly when it comes to fixed-length cable tensioning. Temperature and humidity fluctuations can cause material deformation and stress fluctuations, impacting structural stability and construction accuracy. Therefore, a fixed-length cable tensioning construction method that can adapt to these temperature and humidity fluctuations is urgently needed to ensure efficient, precise, and safe construction. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a fixed-length cable tensioning construction method for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference, aiming to solve the problems of deformation difference of steel and wood materials, dynamic environmental compensation and long-term performance degradation.

[0004] The present invention adopts the following technical solutions to solve the above technical problems:

[0005] To solve the above problems, the present invention adopts the following technical solution: a method for tensioning fixed-length cables in a large-span steel-wood composite structure in an environment with a large temperature and humidity difference, characterized in that it specifically includes the following steps:

[0006] A method for tensioning fixed-length cables in a large-span steel-wood composite structure in an environment with a large temperature and humidity difference, characterized in that it specifically comprises the following steps:

[0007] S1: nanohydrophobic modification of wood;

[0008] S2: Steel anti-corrosion and temperature control treatment;

[0009] S3: Install smart anchors and sensor networks;

[0010] S4: staged dynamic tensioning construction;

[0011] S5: Interface strengthening and protection;

[0012] S6: BIM model comparison and acceptance.

[0013] Furthermore, in step S1, the wood (1) is placed in a vacuum chamber, a nano-SiO2 modifier is injected, and a graphene composite coating is coated on the surface.

[0014] The steel anti-corrosion and temperature control treatment in step S2 is specifically performed as follows:

[0015] S2-1: Sandblast the steel (2) (3) to remove rust, and apply dry film epoxy zinc-rich primer and dry film fluorocarbon topcoat;

[0016] S2-2: The steel cable is wrapped with a paraffin-based phase change material PCM sheath.

[0017] In the further step S3, the smart anchor and sensor network are installed, and the specific steps are as follows:

[0018] S3-1: The temperature sensor (5) is embedded in the inner wall of the front cover, close to the surface of the steel cable (3), fixed by screw threads, and coated with thermal grease on the surface;

[0019] S3-2: The hydraulic fine-tuning mechanism (7) is located in the middle of the adjustment chamber, connecting the front cover and the rear cover, and connected to the external hydraulic pump station through the oil pipe (8);

[0020] S3-3: The three disc spring groups (10) are connected in series and positioned between the rear cover and the anchor bolts through a guide sleeve made of brass;

[0021] S4-4: Edge computing module, embedded in the cavity inside the back cover (9), with a cavity sealing ring made of fluororubber, close to the data interface, and communicating with the temperature sensor (5), hydraulic cylinder pressure sensor (7) and external control terminal (9) through waterproof cables;

[0022] Furthermore, the adjusting screw is rigidly connected to the clamp at the end of the steel cable; a fiber optic Bragg grating strain gauge is arranged along the steel cable (3), and the data is uploaded to the cloud analysis platform via the 5G network.

[0023] Furthermore, the dynamic tensioning construction in step S4 is carried out in stages, and the specific operation steps are as follows:

[0024] S4-1: An annular groove is machined on the inner wall for installing a wedge-shaped clip (6); the steel cable (3) is fixed by a pre-tightening bolt (4); a six-axis hydraulic manipulator cluster is used for synchronous tensioning;

[0025] S4-2: Load the cable step by step with a gradient of 20% until it reaches 100% of the design cable force. Tension the cable symmetrically on both sides and superimpose the temperature and humidity compensation values calculated in real time.

[0026] S4-3: After tensioning is completed, modular hydraulic support columns are used to unload in the order of "mid-span → 1 / 4 span → end".

[0027] Furthermore, in step S5, all steel (3) and wood (1) interfaces are filled with polyurethane elastomer, and fractal steel plates 2 are laser-cut using fractal structural steel plate connectors, and flexible nodes are used; the steel cables (3) are coated with microcapsule epoxy resin coatings, and the wood (1) is sprayed with a drug-loaded aerogel film.

[0028] Furthermore, in step S6, a terrestrial 3D laser scanner is used to fully scan the completed structure, generating point cloud data. This scanned data is then imported into comparison software with the designed BIM model, where an ICP algorithm is used to achieve registration at a level of ≤ 2 mm. The BIM model is dynamically linked to the sensor data, displaying structural stress cloud maps and temperature and humidity distribution. Maintenance records are stored on a blockchain, ensuring tamper-proof and traceable security. HoloLens glasses can then overlay virtual data onto the real structure to guide on-site personnel in locating defects.

[0029] The solution adopted by the present invention has the following technical effects:

[0030] 1. The present invention can block the moisture absorption and expansion of wood and improve its volume stability by modifying the wood.

[0031] 2. The present invention can suppress the thermal expansion and contraction of steel and improve the temperature difference control accuracy by processing the steel.

[0032] 3. The present invention carries out temperature and humidity control and dynamic compensation throughout the entire process of intelligent anchor installation, ensuring that construction accuracy is not affected by external interference. It can replace manual experience adjustment and enable full-dimensional environmental and structural status monitoring.

[0033] 4. The present invention implements phased dynamic tensioning and reverse unloading, which can reduce cable force deviation under environmental interference and improve its efficiency by coordinating with machines. It achieves millimeter-level positioning, high-precision synchronization of multiple cables, and adaptability to complex environments, avoids sudden structural instability, and provides an efficient and reliable automation solution.

[0034] 5. The present invention strengthens and protects the interface and adopts flexible nodes to solve the deformation difference of materials, reduce stress concentration, improve durability, and reduce the maintenance cost throughout the life cycle.

[0035] 6. The present invention utilizes BIM technology to reduce energy consumption, improve prediction accuracy, achieve full transparency and traceability of the operation and maintenance process, improve maintenance efficiency, and realize digital management and control of the entire construction-operation and maintenance cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0037] Figure 1 This is a flow chart of the fixed-length cable tensioning construction method for a large-span steel-wood composite structure in an environment with a temperature and humidity difference according to the present invention;

[0038] Figure 2 is an elevation view of the steel-wood composite truss in this embodiment;

[0039] Figure 3 is a plan view of the steel-wood composite truss in this embodiment;

[0040] Figure 4 is a cross-sectional view of the steel-wood composite truss in this embodiment;

[0041] Figure 5 This is a detailed diagram of the installation of the smart anchor in this embodiment. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0043] This embodiment provides a method for tensioning fixed-length cables in a large-span steel-wood composite structure under a temperature and humidity difference environment. Figure 1 As shown, the specific process is as follows:

[0044] Step S1, wood nano-hydrophobic modification.

[0045] The wood 1 is placed in a vacuum chamber, injected with a nano-SiO2 modifier, pressurized to 1.5 MPa, and coated with a graphene composite coating on the surface.

[0046] Step S2: Steel anti-corrosion and temperature control treatment.

[0047] S2-1: Sandblast and derust steels 2 and 3 to Sa2.5, then apply epoxy zinc-rich primer with a dry film thickness of 80 μm and fluorocarbon topcoat with a dry film thickness of 40 μm;

[0048] S2-2: The steel cable is wrapped with a paraffin-based phase change material PCM sheath with a phase change temperature of 25±2°C. The electric heating system is used to control the temperature fluctuation of the steel cable to ≤±3°C.

[0049] Step S3: Install smart anchors and sensor networks.

[0050] S3-1: Temperature sensor 5 has an accuracy of ±0.5°C and is embedded in the inner wall of the front cover, close to the surface of the steel cable 3 and 5 mm away from the wedge-shaped clip 6. Two sensors are symmetrically arranged and fixed with threads. The surface is coated with thermal grease.

[0051] Furthermore, the adjusting screw has a diameter of 30 mm and a thread accuracy of 0.01 mm, and is rigidly connected to the clamp at the end of the steel cable.

[0052] S3-2: The hydraulic fine-tuning mechanism 7 is located in the middle of the adjustment chamber, connecting the front cover and the rear cover, with a stroke of ±10mm and a thrust of 5kN. It is connected to the external hydraulic pump station through the oil pipe 8;

[0053] S3-3: The three disc spring groups 10 are connected in series and positioned between the rear cover and the anchor bolts through a brass guide sleeve;

[0054] Furthermore, the disc spring has an outer diameter of 80 mm, an inner diameter of 40 mm, and a thickness of 5 mm.

[0055] S3-4: Edge computing module, embedded in the cavity 9 inside the back cover, with a cavity seal made of fluororubber, close to the data interface, with a protection level of IP67, and communicating with the temperature sensor 5, hydraulic cylinder pressure sensor 7, and external control terminal 9 through waterproof cables. According to the formula ΔL = 12 × 10 -6 ×L×ΔT+0.015%×L×ΔRH real-time compensation of cable length, compensation accuracy ±1mm / 100m;

[0056] Furthermore, fiber Bragg grating strain gauges with a resolution of 5με are arranged every 5m along the steel cable 3, and three temperature and humidity sensors 5 with an accuracy of ±0.5℃ / ±2%RH are arranged every 100㎡. The data is uploaded to the cloud analysis platform via the 5G network.

[0057] Step S4 is to perform dynamic tensioning construction in stages.

[0058] S4-1: An annular groove with an outer diameter of 150 mm, a length of 100 mm, a flange edge thickness of 20 mm, and a depth of 5 mm is machined into the inner wall for mounting a wedge-shaped clip 6. The clip is made of high-carbon steel with a hardness of HRC55, a taper of 1:1, and a uniform distribution of 120°. The cable 3 is secured with preloaded bolts 4. A six-axis hydraulic robotic arm cluster with a repeatability accuracy of ±0.1 mm is used for synchronous tensioning, achieving 60% of the designed cable force. The wood moisture content fluctuation is monitored for 24 hours to ≤±1% and the node displacement is ≤2 mm.

[0059] S4-2: Load the temporary support system step by step with a 20% gradient, with a spacing of ≤1.5m. Each step is loaded to 100% of the design cable force with an interval of 30 minutes between each step. The tensioning is carried out symmetrically on both sides, and the temperature and humidity compensation values calculated in real time are superimposed.

[0060] S4-3: After tensioning is completed, modular hydraulic support columns are used to unload in the order of "mid-span → 1 / 4 span → end", with an unloading rate of ≤2mm / min, a deflection recovery rate of ≥95%, a bearing capacity of 500t, and a stroke of ±50mm.

[0061] Step S5: interface strengthening and protection.

[0062] All steel 3 and wood 1 interfaces are filled with polyurethane elastomer with an injection pressure of 0.5 MPa; the fractal structural steel plate 2 connectors are laser-cut fractal steel plates with a porosity of 30%, and flexible nodes are used; the steel cable 3 is coated with a microcapsule epoxy resin coating, and the wood 1 is sprayed with a drug-loaded aerogel film.

[0063] Step S6: BIM model comparison and acceptance.

[0064] A terrestrial 3D laser scanner is used to perform a full-area scan of the completed structure to generate point cloud data. The scanned data and the designed BIM model are imported into comparison software, and the ICP algorithm is used to achieve alignment of less than or equal to 2 mm. The BIM model is dynamically bound to the sensor data to display the structural stress cloud map, temperature and humidity distribution, and the blockchain stores maintenance records, which are tamper-proof and traceable. Virtual data is superimposed on the real structure through HoloLens glasses to guide on-site personnel in locating defects.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for tensioning fixed-length cables in a large-span steel-wood composite structure in an environment with a large temperature and humidity difference, characterized in that: The specific steps include: S1: nano-hydrophobic modification of wood; S2: Steel anti-corrosion and temperature control treatment; S3: Install smart anchors and sensor networks; S4: staged dynamic tensioning construction; S5: Interface strengthening and protection; S6: BIM model comparison and acceptance.

2. The method for tensioning fixed-length cables for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference according to claim 1 is characterized in that: In step S1, the wood (1) is placed in a vacuum chamber, a nano-SiO2 modifier is injected, and a graphene composite coating is coated on the surface.

3. The method for tensioning fixed-length cables for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference according to claim 1, characterized in that: Step S2, steel anti-corrosion and temperature control treatment, the specific operations are as follows: S2-1: Sandblast the steel (2) (3) to remove rust, and apply dry film epoxy zinc-rich primer and dry film fluorocarbon topcoat; S2-2: The steel cable is wrapped with a paraffin-based phase change material PCM sheath.

4. The method for tensioning fixed-length cables for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference according to claim 1 is characterized in that: Step S3: Install the smart anchor and sensor network. The specific steps are as follows: S3-1: The temperature sensor (5) is embedded in the inner wall of the front cover, close to the surface of the steel cable (3), fixed by screw threads, and coated with thermal grease on the surface; S3-2: The hydraulic fine-tuning mechanism (7) is located in the middle of the adjustment chamber, connecting the front cover and the rear cover, and connected to the external hydraulic pump station through the oil pipe (8); S3-3: The three disc spring groups (10) are connected in series and positioned between the rear cover and the anchor bolts through a guide sleeve made of brass; S3-4: Edge computing module, embedded in the cavity inside the back cover (9), with a cavity sealing ring made of fluororubber, close to the data interface, and communicating with the temperature sensor (5), hydraulic cylinder pressure sensor (7) and external control terminal (9) through waterproof cables.

5. The method for tensioning fixed-length cables for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference according to claim 4 is characterized in that: The adjusting screw is rigidly connected to the clamp at the end of the steel cable; a fiber optic Bragg grating strain gauge is arranged along the steel cable (3), and the data is uploaded to the cloud analysis platform via the 5G network.

6. The method for tensioning fixed-length cables for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference according to claim 1, characterized in that: Step S4, dynamic tensioning construction in stages, the specific operation steps are as follows: S4-1: An annular groove is machined on the inner wall for installing a wedge-shaped clip (6); the steel cable (3) is fixed by a pre-tightening bolt (4); a six-axis hydraulic manipulator cluster is used for synchronous tensioning; S4-2: Load gradually with a gradient of 20% until it reaches 100% of the designed cable force. Tensioning is carried out symmetrically on both sides, and real-time calculated temperature and humidity compensation values are superimposed. S4-3: After tensioning is completed, modular hydraulic support columns are used to unload in the order of "mid-span → 1 / 4 span → end".

7. The method for tensioning fixed-length cables for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference according to claim 1, characterized in that: In step S5, all steel (3) and wood (1) interfaces are filled with polyurethane elastomer, and fractal structural steel plates (2) are laser-cut with connectors, and flexible nodes are used; the steel cables 3 are coated with microcapsule epoxy resin coating, and the wood (1) is sprayed with drug-loaded aerogel film.

8. The method for tensioning fixed-length cables for a large-span steel-wood composite structure in an environment with a large temperature and humidity difference according to claim 1, characterized in that: In step S6, a terrestrial 3D laser scanner is used to scan the entire as-built structure, generating point cloud data. This scanned data is then imported into comparison software with the designed BIM model, where it is aligned to within a 2mm level using the ICP algorithm. The BIM model is dynamically linked to the sensor data, displaying structural stress cloud maps and temperature and humidity distribution. Maintenance records are stored on the blockchain, ensuring tamper-proof and traceable security. HoloLens glasses are used to overlay virtual data onto the real structure, guiding on-site personnel in locating defects.

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