A cable layering and synchronous laying construction method

Abstract

The application discloses a cable layered synchronous laying construction method, comprising the following steps: pre-planning and bridge precise pre-positioning marking before construction; layered guide and isolation tooling pre-adaptation in the bridge; layered synchronous laying and integrated fixing, adopting the layered closed construction logic of from top to bottom, layer-by-layer construction, laying and fixing, and next layer entering after completion of the previous layer; special node synchronous protection and working condition adaptation processing, which is carried out synchronously with laying operation, and the corresponding node protection is completed when laying each layer; stage closed-loop verification and global completion acceptance, which can significantly reduce the safety risk of high-altitude operation and improve the construction efficiency and one-time acceptance pass rate.

Description

Technical Field

[0001] This invention relates to the field of electrical engineering cable laying construction technology, and more specifically, to a method for laying cables in layers simultaneously. Background Technology

[0002] In the metallurgical, chemical, and power industries, large-span industrial plants commonly use elevated cable trays for centralized cable laying. The cable trays are typically installed at an elevation of 6–12 meters, with long continuous laying distances, often exceeding tens of meters in a single section. This necessitates the simultaneous laying of multiple specifications and circuits of cables, including high-voltage power, low-voltage power, and control cables.

[0003] The current industry-standard sequential construction process is as follows: overall cable tray installation completed → centralized cable dragging along the entire line → workers enter the high-altitude cable tray for manual cable arrangement → binding and fixing → subsequent addition of circuit labels. This traditional process has several inherent defects:

[0004] (1) High safety risk: Workers need to crawl inside the hollow cable tray for a long time to arrange and tie the cables. The working area is narrow and close to the edge at high altitude, which makes it easy to fall and get stuck. This is a common cause of injury and death in electrical engineering high-altitude operations.

[0005] (2) Construction quality hazards are prominent: During the process of dragging a large number of cables, cross-entanglement and local knotting are likely to occur; manual forced combing can easily cause scratches on the outer sheath of the cable or damage to the insulation layer, which may lead to short circuit and leakage faults in later operation.

[0006] (3) Low construction efficiency and easy to delay the construction period: The laying and cable management need to be carried out in two separate high-altitude operations. The cable management process usually takes several times longer than the laying process, resulting in a significant increase in labor costs and easy to cause delays in the overall construction period.

[0007] (4) High error rate of circuit identification: Temporary identification is easy to wear off and fall off during long-distance dragging. If the identification is reattached based solely on memory or experience, there is a high risk of mixed or incorrect identification of circuits, which leads to rework of wiring and affects the accuracy of subsequent operation and maintenance.

[0008] (5) Poor compliance with standards: During the manual cable management process, power cables and control cables are often not laid in layers or separately as required by the standards, which deviates from the relevant requirements of GB50217-2018 "Design Standard for Cables in Power Engineering", resulting in increased acceptance and rectification costs.

[0009] (6) Existing technology optimization has limitations: Currently, most of the relevant improvement solutions in the industry focus on local optimization of hardware such as traction equipment and cable laying tools, and rarely address systemic problems from the root causes of construction process reorganization, layered laying logic and high-altitude operation mode. It is difficult to achieve the core goals of zero cross-entanglement, elimination of crawling operation in cable trays and inherently low-risk construction. Summary of the Invention

[0010] The purpose of this invention is to address the problems mentioned in the background section by providing a method for synchronous layered cable laying. This method employs an integrated and innovative process that integrates pre-planning and positioning, tooling isolation and guidance, layer-by-layer laying and fixing, phased closed-loop verification, and full-process finished product protection. It eliminates manual crawling operations inside cable trays, prevents cable cross-entanglement and mixed-layer wiring from the source, reduces the risks of high-altitude operations, improves construction quality and acceptance rate, shortens the construction period, reduces rework, and is suitable for complex industrial conditions such as explosion-proof, corrosion-resistant, and high-voltage heavy-load applications.

[0011] The present invention adopts the following technical solution:

[0012] A method for synchronous layered cable laying includes the following steps:

[0013] Step S1: Conduct preliminary planning and precise pre-positioning and marking of cable trays before construction;

[0014] Step S2: Pre-installation and adaptation of layered guide and isolation fixtures within the cable tray;

[0015] Step S3: Layered synchronous laying and integrated fixing, adopting a layer-by-layer closed construction logic from top to bottom, layer by layer construction, fixing immediately after laying, and inspecting before moving to the next layer;

[0016] Step S4: Synchronous protection and working condition adaptation of special nodes are carried out simultaneously with the laying operation in Step S3. The protection of the corresponding nodes is completed during the laying of each layer.

[0017] Step S5: Phased closed-loop verification and full-domain completion acceptance.

[0018] Beneficial effects

[0019] (1) Safety risks are greatly reduced: The elimination of manual climbing operations inside the cable tray significantly reduces the time spent working at height, thereby reducing the risk of falls and missteps, which meets the requirements of safety production standards.

[0020] (2) Construction efficiency and construction period are greatly optimized: laying, tidying, binding and marking are completed at the same time, forming a complete structure in one go, without the need for secondary high-altitude rectification work, greatly improving the overall construction efficiency and significantly reducing labor costs.

[0021] (3) Construction quality has been significantly improved: Through pre-planning, pre-positioning, and layered isolation throughout the process, the cable cross-entanglement rate has been significantly reduced, the damage rate of cable outer sheath and insulation layer has been significantly reduced, the accuracy of signage has been significantly improved, the problems of mixed lines and wrong signs have been completely solved, and the first-time pass rate of acceptance has been greatly improved.

[0022] (4) Full process traceability and replicability: The standardized hierarchical planning and phased verification process, all parameters comply with the current national standards, and can be directly replicated to cable tray laying projects in various industrial and civil buildings, adapting to the development trend of standardized construction in the industry.

[0023] (5) No additional cost investment: This invention does not rely on any new equipment or non-standard materials. It uses all conventional auxiliary materials on the construction site. By optimizing the construction process and procedure logic, it can achieve a dual improvement in construction quality and efficiency. There is no additional construction cost investment, and it is very easy to promote and implement in the industry. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the overall process flow of the cable layered synchronous laying method of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] The following example uses a high-altitude ladder-type cable tray project in a large-span steel structure workshop in the metallurgical industry. The cable tray is installed at an elevation of 10m and has a single span of 120m. It is necessary to lay three layers of 10kV high-voltage power cables, 0.4kV low-voltage power cables, and control cables simultaneously.

[0027] This invention discloses a method for synchronous layered cable laying, comprising the following steps:

[0028] Step S1: Conduct preliminary planning and precise pre-positioning and marking of cable trays before construction.

[0029] S1.1 Parameter Acquisition: Comprehensive data acquisition of cable tray specifications (width × height), routing, installation elevation, and single-span length; cable voltage rating, specifications, circuit number, start and end points, and total laying quantity; simultaneous data acquisition of basic data such as the steel structure layout of the factory building, high-altitude working environment, and corrosion and explosion protection ratings. Safety technical briefings must be completed before construction, and personnel working at heights must hold valid high-altitude work qualification certificates; operations within explosion-proof areas must comply with relevant explosion-proof construction management regulations.

[0030] S1.2 Layered Layout Design: Strictly following Article 5.1.3 of GB 50217-2018 "Design Standard for Cables in Power Engineering", cables within the cable tray should be arranged in a "top-down" order, from high to low voltage power cables and from high-voltage to low-voltage control cables. When the horizontal channel contains high-voltage cables above 35kV, they should be arranged in a "bottom-up" order. The left-right arrangement sequence and loop locations of individual cables within each layer should be clearly defined, and standardized layered layout construction drawings should be generated. In this embodiment, the top layer contains 10kV high-voltage power cables, the middle layer contains 0.4kV low-voltage power cables, and the bottom layer contains control cables.

[0031] S1.3 Cable Tray Pre-marking: After the cable tray installation is accepted and before cable laying, workers shall operate from the side or below the cable tray using a movable lifting platform, without entering the interior of the cable tray. Waterproof positioning markers shall be sprayed every 5 meters along the cable tray, indicating layer boundaries, cable arrangement sequence, and circuit numbers. The marking location shall not interfere with the subsequent partition installation location. For corrosive and high-temperature chemical plant rooms, acid- and alkali-resistant, high-temperature-resistant special anti-corrosion marking paint shall be used. For long cable tray sections with large spans, reference points shall be set at both ends, and segmented positioning shall be achieved through laser ranging to control cumulative errors.

[0032] S1.4 Pre-fabricated identification: Customize permanent cable identification tags in advance, indicating the circuit number, cable specifications, start and end points, and the layer to which it belongs; use temporary easy-tear tags during the laying stage to reduce dragging, jamming, and sheath scratches.

[0033] Step S2: Pre-installation and adaptation of layered guide and isolation fixtures within the cable tray

[0034] S2.1 Insulation Separator Installation: Insulation separators with a flame retardant rating of not less than V-0 (refer to GB / T 2408-2008) shall be used, and the withstand voltage rating shall match the on-site high-voltage cable conditions; separators and auxiliary materials in explosion-proof areas shall comply with explosion-proof selection standards to prevent static electricity accumulation. Separators shall be fixed with non-drilling clips: ladder-type cable trays shall use through-clamp clips, and trough-type cable trays shall use side-wall clamp clips, without damaging the anti-corrosion layer of the cable tray. Separators at key nodes separating strong and weak current shall be permanently retained; temporary separators on straight sections shall be removed using special tools after the single-layer construction has passed acceptance, to avoid scratching the finished cables.

[0035] S2.2 Pre-installation of guide fixtures: At the turning, diameter changing and lifting nodes of the cable tray, wear-resistant reinforced nylon guides are pre-installed on each layer. The snap-fit ​​fixing does not require welding, cutting or drilling. It guides the cable to drag along the planned path, reducing sheath scratches, cable knots and cross-layer mixing.

[0036] S2.3 Tooling universality: All partitions, guides and buckles use standard auxiliary materials commonly used on construction sites, and there is no need to customize non-standard materials.

[0037] Step S3: Layered synchronous laying and integrated fixing

[0038] S3.1 Laying in layers: Starting with the top high-voltage power cable, the next layer can only be laid after the entire single layer has been completed and accepted, in order to avoid cross-interference between upper and lower layer cables.

[0039] S3.2 Standardized Cable Traction: For single cable traction, only temporary markers are retained. Cable positioning is controlled using pre-positioned markers, isolation partitions, and guides. Cable laying must comply with the requirements for cable laying within structures in Section 6.4 of GB 50168-2018, including lateral pressure control and turning radius requirements. Lightweight alloy temporary supports are added every 20-30m for long-span cable trays. The support's load-bearing capacity is no less than three times the maximum self-weight of a single cable. Installation photos and load verification data are kept for the supports and included in the concealed works file after being approved by the supervisor.

[0040] S3.3 Non-crawling precision operation: After the cable is dragged into place, temporary fixing is completed inside the lifting platform; after all single-layer cables are laid, cable management and binding are completed inside the platform using lightweight tools such as extended insulating hooks and adjustable binding guns. Personnel are prohibited from entering the cable trays to crawl in areas such as bends and tees.

[0041] S3.4 Standardized Binding: Strictly adhere to GB 50168-2018 "Standard for Construction and Acceptance of Cable Lines in Electrical Installations" and the relevant fixing requirements in Chapter 6 of GB 50217-2018. The binding spacing for control cables should not exceed 800mm, and the binding spacing for conventional power cables should not exceed 1000mm. For large cross-section cables (240mm² and above) and high-voltage heavy-duty cables, the binding spacing should be appropriately increased. Use insulated nylon cable ties, with appropriate tightness, to protect the cable sheath. The safety distance between cables and facilities such as heating pipes should comply with the provisions of Clause 5.1.7 of GB 50217-2018.

[0042] S3.5 Permanent Identification Installation: After the single-layer binding is completed, the prefabricated permanent identification signs shall be fixed to the cable body (without being attached to the cable tray or partition), and the signs shall be installed in accordance with the specifications at both ends of the cable, at bends, and every 50m on straight sections.

[0043] S3.6 Finished Product Protection: Before construction on the lower layer, a fire-retardant protective layer (such as a fire blanket) shall be laid over the area of ​​the completed cables above to prevent tools and materials from falling and scratching the finished product. Cable ends shall be kept sealed during and after laying to prevent moisture intrusion.

[0044] Step S4: Synchronization Protection and Working Condition Adaptation for Special Nodes

[0045] This step is carried out simultaneously with the laying operation in step S3, and the corresponding node protection is completed during the laying of each layer.

[0046] S4.1 Bending Radius Control: Implemented differently according to cable type—the bending radius of unarmored cables shall not be less than 6 times the cable's outer diameter, and for armored cables, not less than 12 times; the bending radius of power cables shall comply with GB / T 12706.2-2020 (not less than 15 times the cable's outer diameter for unarmored three-core cables, and not less than 12 times for armored three-core cables); ultra-high voltage cables shall comply with the manufacturer's technical parameters. Hard bending and twisting of cables are strictly prohibited.

[0047] S4.2 Interface Protection: Waterproofing and scratch protection should be carried out simultaneously at the locations where cables enter and exit cable trays, distribution cabinets, and equipment cabinets; fire-resistant bags and fireproof sealant should be used to seal the locations where cables pass through walls, floors, and fire compartments in compliance with regulations, and fireproof sealing concealment acceptance records should be kept.

[0048] S4.3 Dragging Protection: Direct dragging of bare cables on steel structures and rough ground is strictly prohibited at all times. Long-distance bends must be monitored by designated personnel equipped with traction gauges for real-time monitoring. The traction strength of copper conductors must not exceed 70 MPa, and the traction strength of aluminum conductors must not exceed 40 MPa (based on 1 / 4 of the conductor's tensile strength). Monitoring records must be maintained in accordance with the manufacturer's parameters to prevent conductor breakage and insulation damage.

[0049] Step S5: Phased closed-loop verification and full-domain completion acceptance

[0050] S5.1 Single-layer sub-item acceptance: After each layer of laying, binding, and marking is completed, a special test shall be carried out immediately. The test results must be submitted to the supervisor for approval before proceeding to the next layer. The test content includes:

[0051] • Visual integrity inspection;

[0052] • Compliance check of layered layout (check each item against the layout construction drawings);

[0053] • Quality inspection of node protection (bending radius, interface protection, fireproof sealing, etc. for S4 nodes);

[0054] • Wire continuity test;

[0055] • Insulation resistance test: 1000V megohmmeter is used for cables below 1kV, 2500V megohmmeter is used for cables of 1kV and above, and 5000V megohmmeter can also be used for cables of 6 / 6kV and above.

[0056] • Substandard cables should be replaced or rectified immediately.

[0057] S5.2 Segmented Flow Improvement: Long-span cable trays are divided into independent construction segments of 100-150m, and each segment is carried out simultaneously with layered construction and acceptance.

[0058] S5.3 Full-area completion acceptance: After the entire line is laid, a comprehensive review shall be carried out, including compliance of layered layout, binding quality, accuracy of marking, and retesting of insulation throughout the line; additional AC or DC withstand voltage tests shall be conducted on high-voltage cables above 1kV as a necessary condition for completion acceptance.

[0059] S5.4 Document Archiving: All test data, image data, layout drawings, concealed works records, and fireproofing and sealing data shall be compiled into a complete as-built ledger and handed over for later operation, maintenance and repair.

[0060] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A method for synchronous layered cable laying, characterized in that, Includes the following steps: Step S1: Before construction, conduct preliminary planning and precise pre-positioning and marking of cable trays. Collect comprehensive basic data such as cable tray specifications, routing, installation elevation, single span, cable voltage level, specifications, circuit number, start and end points, and total laying volume. Develop a layered layout construction drawing. After the cable tray installation is accepted and before cable laying, complete the pre-marking of the cable trays and prefabrication of signboards without entering the inside of the cable trays. Step S2: Pre-install and adapt the layered guide and isolation fixtures inside the cable tray. Install insulating partitions between the cable tray layers using non-drilling clips. Pre-install wear-resistant guide components at turning, diameter changing, and lifting nodes to form independent guide channels for each layer. Step S3 adopts a top-down, layer-by-layer construction logic, with each layer being laid and then fixed immediately, and the next layer being inspected before proceeding to the next layer. This completes the layered synchronous laying and integrated fixing. The entire process relies on a lifting platform to work on the side or below the cable tray, and personnel are prohibited from entering the cable tray to crawl. Step S4, in conjunction with step S3, carries out special node protection and working condition adaptation processing, including bending radius control, interface protection and drag protection; Step S5: Conduct phased closed-loop verification and full-area completion acceptance. After each layer is laid, conduct single-layer sub-item acceptance immediately. Only after the acceptance is qualified can the next layer be constructed. After the entire line is completed, conduct full-area completion acceptance and complete the data archiving.

2. The method for synchronous layered laying of cables according to claim 1, characterized in that: The pre-marking of the cable trays in step S1 specifically involves: Workers operate from the side or below the cable tray using a mobile lifting platform, spraying waterproof positioning marks every 5 meters along the cable tray to indicate layer boundaries, cable arrangement sequence, and circuit numbers. The marking position does not interfere with the subsequent partition installation position. For corrosive or high-temperature chemical plants, acid and alkali resistant and high-temperature resistant special anti-corrosion marking paint is used. For long sections of cable tray, reference points are set at both ends, and laser ranging is used for segmented positioning to control cumulative errors.

3. The method for synchronous layered laying of cables according to claim 1, characterized in that: The layered layout design in step S1 follows these rules: Cables within the cable tray are arranged in descending order of voltage level, from power cables to control cables from high voltage to low voltage, and from top to bottom. When there are high voltage cables of 35kV or above in the horizontal channel, they are arranged from bottom to top. The left-right arrangement order and circuit point of each single cable in each layer are clearly defined, and standardized layered layout construction drawings are output.

4. The method for synchronous layered laying of cables according to claim 1, characterized in that: The installation of the insulating partition in step S2 is specifically as follows: The flame retardant rating of the partition is not lower than V-0, and the pressure resistance rating matches the on-site high-voltage cable conditions; ladder-type cable trays are fixed with through-clamp clips, and trough-type cable trays are fixed with side-wall clamp clips, neither of which damages the anti-corrosion layer of the cable tray; the partitions at key nodes separating strong and weak current are permanently retained, and the temporary partitions on straight sections are removed using special tools after the single-layer construction is accepted.

5. The method for synchronous layered laying of cables according to claim 1, characterized in that: The layered synchronous laying and integrated fixing in step S3 specifically includes: For single-cable dragging, only temporary markers are retained, and cable positioning is controlled by pre-positioned markers, isolation partitions, and guide components. For long-span cable trays, lightweight alloy temporary brackets are added every 20-30m, with the brackets bearing a load of no less than three times the maximum self-weight of a single cable. After all single-layer cables are laid, lightweight chemical equipment such as extended insulating hooks and adjustable binding guns are used to complete cable management and binding within a lifting platform. The binding spacing of controlled cables is no more than 800mm, and the binding spacing of conventional power cables is no more than 1000mm, using insulated nylon cable ties. After single-layer binding is completed, prefabricated permanent markers are fixed to the cable body, and markers are standardized at both ends of the cable, at bends, and every 50m on straight sections. Before the construction of the next layer, a fireproof and flame-retardant protective layer is laid in the area of ​​the completed cables above.

6. The method for synchronous layered laying of cables according to claim 1, characterized in that: The bending radius control in step S4 is implemented differently according to cable type: The bending radius of unarmored control cables shall not be less than 6 times the outer diameter of the cable, and not less than 12 times the outer diameter of armored cables; the bending radius of unarmored three-core cables shall not be less than 15 times the outer diameter of the cable, and the bending radius of armored three-core cables shall not be less than 12 times the outer diameter of the cable; ultra-high voltage cables shall be manufactured in accordance with the manufacturer's technical parameters.

7. The method for synchronous layered laying of cables according to claim 1, characterized in that: The drag protection in step S4 specifically refers to: Dragging bare cables directly on steel structures or rough ground is strictly prohibited throughout the entire process; at long-distance bends, a dedicated person shall be assigned to monitor the area and a traction meter shall be provided for real-time monitoring. The traction strength of copper conductors shall not exceed 70 MPa, and the traction strength of aluminum conductors shall not exceed 40 MPa.

8. The method for synchronous layered laying of cables according to claim 1, characterized in that: Step S4 also includes interface protection: Waterproofing and scratch protection were simultaneously applied to the locations where cables entered and exited cable trays, distribution cabinets, and equipment cabinets; fire-resistant bags and fireproof sealant were simultaneously applied to the locations where cables passed through walls, floors, and fire compartments in compliance with regulations.

9. A method for synchronous layered cable laying according to claim 1, characterized in that: The single-layer sub-item acceptance in step S5 includes: The inspection includes visual integrity checks, compliance checks of layered layout, quality checks of node protection, continuity checks of core wires, and insulation resistance tests. Cables below 1kV use a 1000V megohmmeter, cables of 1kV and above use a 2500V megohmmeter, and cables of 6 / 6kV and above can use a 5000V megohmmeter. Non-conforming cables must be replaced and rectified immediately.

10. A method for synchronous layered cable laying according to claim 1, characterized in that: Step S5 also includes: dividing long-span cable trays into independent construction sections of 100-150m, with each section undergoing simultaneous layered construction and acceptance; conducting full-area completion acceptance after the entire line is laid, and adding AC or DC withstand voltage tests for high-voltage cables above 1kV as a necessary condition for completion and acceptance.

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