Construction method for laying 35KV current collection line cable

Abstract

The invention discloses a construction method for cable laying of a 35KV current collection line, relates to the technical field of electric power engineering construction, and aims to solve the problem that key parameters in the cable laying process are difficult to accurately control by a traditional construction method. Technology and field preparation, personnel preparation, equipment and material preparation and machinery and tool preparation are completed, and it is ensured that data, personnel, materials and equipment needed by construction are in place and meet the requirements; s2, cable trench excavation is carried out, paying-off excavation is carried out according to design requirements, the sloping coefficient and the excavation depth are controlled, a trench base and special conditions are well treated, and soft soil or fine sand is laid at the trench bottom after excavation; and S3, cable laying: laying the cable in the cable trench in a direct burial manner, controlling the cable spacing, the traction force and the turning radius, and performing cable protection and joint configuration. The method has the advantage that key parameters in the cable laying process can be accurately controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of power engineering construction, and more specifically, to a construction method for laying 35KV collector line cables. Background Art

[0002] In the field of 35KV collector line construction, the quality of cable laying construction is directly related to the operation stability and safety of the line. With the continuous growth of power demand, the scale of 35KV collector line projects is expanding, posing higher requirements for cable laying construction technology.

[0003] In the construction of 35KV collector line cable laying, traditional construction methods are difficult to accurately control key parameters during cable laying, such as the traction force and bending radius of the cable, which easily lead to problems such as damage to the internal structure of the cable and rupture of the outer skin, greatly affecting the service life of the cable and power transmission performance, and increasing potential safety hazards in line operation. In view of this, we propose a construction method for laying 35KV collector line cables. Summary of the Invention

[0004] The purpose of the present invention is to provide a construction method for laying 35KV collector line cables, aiming to solve the problem that traditional construction methods are difficult to accurately control key parameters during cable laying.

[0005] To solve the above technical problems, the present invention provides the following technical solution: A construction method for laying 35KV collector line cables, the method comprising the following steps:

[0006] S1: Construction preparation, complete technical and site preparation, personnel preparation, equipment and material preparation, and machinery and tool preparation to ensure that the required construction materials, personnel, supplies, and equipment are in place and meet the requirements;

[0007] S2: Cable trench excavation, carry out excavation according to the design requirements, control the slope coefficient and excavation depth, handle the trench bottom and special situations, and lay soft soil or fine sand at the bottom of the trench after excavation;

[0008] S3: Cable laying, lay the cable in the cable trench in a direct burial manner, control the cable spacing, traction force, and turning radius, do a good job in cable protection and joint configuration, set up a liaison and command system, and insulate or warm the cable during winter construction;

[0009] S4: Installation of cable intermediate joints / terminals, fabricate cable intermediate joints and terminals according to the cable type and specific procedures, and carry out grounding installation for the cable using a two-end grounding method;

[0010] S5: Cable testing, conduct insulation resistance testing and withstand voltage testing on the cable after cable laying is completed;

[0011] S6: Fireproof sealing / painting, conduct fireproof sealing and painting construction on the cable pipe inlets and outlets and specific areas;

[0012] S7: Hidden acceptance, invite relevant units to conduct hidden acceptance of the cable laying project;

[0013] S8: Backfilling, conduct backfilling after passing the hidden acceptance, compact in layers and lay protection plates and warning tapes;

[0014] S9: Burying marker posts, bury marker posts at specified positions along the cable path.

[0015] Preferably, in the above step S1, the insulation of the cable is measured before laying. When the temperature during construction is lower than 5°C, the cable is heat-insulated 2 - 3 days in advance.

[0016] Preferably, in the above step S2, the cable trench base needs to be compacted, and the bottom width should meet the requirement that the bottom parts of both side walls are 150 mm away from the cable respectively, and the mutual horizontal clear distance of the cables is 250 mm.

[0017] Preferably, in the above step S3, the cable laying is carried out by manual traction, and the traction force of the cable is monitored in real time not to exceed the allowable traction force of the cable. The cable is led out from the upper end of the cable reel, and the cable bending radius requirement is met at the turning points.

[0018] Preferably, in the above step S4, the cable head production includes stripping the outer sheath, stripping the armor layer, stripping the inner cushion layer, separating the core wires, welding the ground wire, wrapping the filling rubber, fixing the three-finger sleeve, stripping the copper shielding layer, fixing the stress tube, pressing the wire nose, fixing the insulating tube, and fixing the phase color sealing tube.

[0019] Preferably, in the above step S6, at both sides 1.5 m away from the fireproof sealing point of the cable, the fireproof paint is brushed 5 - 7 times, and the thickness is ≥1 mm after drying.

[0020] Preferably, in the above step S8, after backfilling 100 mm of soft soil or fine sand on the top of the cable, a concrete protection plate is laid. The unilateral width of the protection plate extends 50 mm beyond the cable outer skin. After backfilling 300 mm of soil on the top of the protection plate, a cable warning tape is laid directly above each high-voltage cable.

[0021] Preferably, in the above step S9, along the cable path, obvious cable marker posts are set at intervals of 50 m in a straight line, 20 m at the turning points and cable joint points. The cable posts protrude 300 mm above the ground.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. Through a series of measures such as perfect construction preparation, precise cable trench excavation, strict control of cable laying parameters, delicate joint fabrication, and reliable grounding installation, the present invention ensures the quality of cable laying, reduces cable damage and potential faults, and improves the stability and reliability of the 35KV collector line.

[0024] 2. By fully identifying and controlling various safety risks, such as the protection of underground facilities during cable trench excavation and safety operation specifications during cable laying, the present invention effectively reduces the incidence of safety accidents during construction.

[0025] 3. By utilizing reasonable personnel, equipment, and material allocation, as well as scientific construction process arrangements, the present invention improves construction efficiency and ensures the project is completed on time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic flow chart of the method in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0028] Embodiment 1

[0029] As Figure 1 shown: Technical personnel comprehensively review the construction drawings, prepare a detailed construction plan in combination with the actual on-site situation, organize construction personnel for technical disclosure and safety training, purchase materials such as cables, protection pipes, and fireproof materials that meet the design requirements, ensure that the cables have factory certificates and all performance indicators are qualified, conduct insulation measurement before laying, and at the same time prepare machinery and tools such as excavators, wire laying pulleys, and winches, and check their performance.

[0030] According to the design drawings, lay out the lines to determine the position of the cable trench, excavate according to a slope coefficient of 1:0.75, with the depth controlled at 1.5m. During the excavation process, when encountering tree roots, clean them in a timely manner. Use a rammer to compact the bottom of the trench to ensure that the bottom width meets the requirements that the two side walls are 150mm away from the cable respectively, and the horizontal clear distance between cables is 250mm. After excavation, lay 100mm thick fine sand at the bottom of the trench and compact it.

[0031] The cable is laid by means of manual traction. A tension sensor is set at the cable reel to monitor the traction force of the cable in real time to ensure that it does not exceed the allowable traction force of the cable. The cable is led out from the upper end of the reel. Guide pulleys are set at the turning points to ensure that the turning radius meets the requirement of 15 times the cable diameter. When laying the cable, the cable spacing is strictly controlled to ensure compliance with the design specifications. Soft soil with a thickness of 100 mm is laid on both the upper and lower sides of the entire length of the cable, and concrete protection plates are covered.

[0032] For the cable, the cable head is made according to the steps of stripping the outer sheath, stripping the armor layer, stripping the inner cushion layer, separating the core wires, welding the ground wire, wrapping the filling rubber, fixing the three-finger sleeve, stripping the copper shielding layer, fixing the stress tube, pressing the wire nose, fixing the insulating tube, and fixing the phase color sealing tube. The cable adopts a two-end grounding method to ensure reliable grounding.

[0033] After the cable laying is completed, professional testing equipment is used for insulation resistance testing and withstand voltage test. According to the test results, it is ensured that all indicators of the cable meet the relevant standard requirements.

[0034] Fireproof blocking is carried out on specific areas such as the cable pipe inlet and outlet and the cable joint. Organic fireproof putty is used to fill it densely. At 1.5 m on both sides of the cable fireproof blocking point, fireproof paint is brushed 5 times, and the thickness reaches 1.2 mm after drying.

[0035] The construction unit, supervision unit, and quality supervision department are invited for concealed acceptance. The acceptance personnel conduct a detailed inspection on the cable laying, joint installation, fireproof blocking, etc. After confirming that it meets the requirements, they sign and pass.

[0036] After the concealed acceptance is qualified, backfilling operation is carried out. First, 100 mm thick soft soil is backfilled on the top of the cable, and then concrete protection plates are laid. The unilateral width of the protection plate extends 50 mm beyond the cable outer skin. 300 mm thick soil is backfilled on the top of the protection plate, and cable warning tapes are laid directly above each high-voltage cable. The backfilled soil is tamped layer by layer.

[0037] Cable marking piles are buried at intervals of 50 m along the straight line of the cable path, 20 m at the turning points and cable joints. The marking piles protrude 300 mm above the ground to ensure clarity and visibility.

[0038] Embodiment 2

[0039] This embodiment is basically the same as Embodiment 1, except that the temperature in the construction area is lower than 5°C, and the cable needs to be insulated 3 days in advance.

[0040] Technical personnel comprehensively review the construction drawings, prepare a detailed construction plan in combination with the actual on-site situation, organize construction personnel for technical disclosure and safety training, purchase materials such as cables, protection pipes, and fireproof materials that meet the design requirements, ensure that the cables have factory certificates and all performance indicators are qualified, conduct insulation measurement before laying, and at the same time prepare machinery and tools such as excavators, wire laying pulleys, and winches, and check their performance.

[0041] Set out the line according to the design drawings to determine the position of the cable trench, excavate according to the slope coefficient of 1:0.75, and control the depth at 1.5m. During the excavation process, when encountering tree roots, clean them up in time. Compact the trench bottom with a rammer to ensure that the bottom width meets the requirement that the two side walls are 150mm away from the cable respectively, and the horizontal net distance between cables is 250mm. After the excavation is completed, lay 100mm thick fine sand at the bottom of the trench and compact it.

[0042] Lay the cable by means of manual traction. Set a tension sensor at the cable reel to monitor the cable traction force in real time to ensure that it does not exceed the allowable traction force of the cable. The cable is led out from the upper end of the reel, and a guiding pulley is set at the turning point to ensure that the turning radius meets the requirement of 15 times the cable diameter. When laying the cable, strictly control the cable spacing to ensure compliance with the design specifications. Lay 100mm thick soft soil on both the upper and lower sides of the entire length of the cable and cover it with a concrete protection board.

[0043] For the cable, make the cable head according to the steps of stripping the outer sheath, stripping the armor layer, stripping the inner cushion layer, separating the core wires, welding the ground wire, wrapping the filling rubber, fixing the three-finger sleeve, stripping the copper shielding layer, fixing the stress tube, pressing the wire nose, fixing the insulating tube, and fixing the phase color sealing tube. The cable adopts the two-end grounding method to ensure reliable grounding.

[0044] After the cable laying is completed, use professional testing equipment to conduct insulation resistance testing and withstand voltage testing. According to the test results, ensure that all cable indicators meet the relevant standard requirements.

[0045] Carry out fireproof sealing for specific areas such as the cable pipe inlet and outlet and the cable joint. Fill it tightly with organic fireproof putty. Brush the fireproof coating 5 times at 1.5m on both sides of the cable fireproof sealing point. After drying, the thickness reaches 1.2mm.

[0046] Invite the construction unit, supervision unit, and quality supervision department for concealed acceptance. The acceptance personnel conduct a detailed inspection of the cable laying, joint installation, fireproof sealing, etc. After confirming that it meets the requirements, sign and pass.

[0047] After the concealed acceptance is qualified, backfilling operations are carried out. First, backfill 100 mm thick of soft soil on top of the cable, then lay a concrete protection board. The unilateral width of the protection board extends 50 mm beyond the cable outer skin. Backfill 300 mm thick of earthwork on top of the protection board, and lay a cable warning tape directly above each high-voltage cable. Compact the backfilled soil in layers.

[0048] Install cable marking piles at intervals of 50 m along the straight line of the cable path, 20 m at the turning points and cable joints. The marking piles protrude 300 mm above the ground to ensure clarity and visibility.

[0049] The embodiments disclosed in the present invention are preferred embodiments, but not limited thereto. Those of ordinary skill in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. As long as they do not depart from the spirit of the present invention, they are within the protection scope of the present invention.

Claims

1. A construction method for laying a 35KV collector line cable, characterized in that: The method comprises the following steps: S1: Construction preparation, complete technical and site preparation, personnel preparation, equipment and material preparation, machinery and tools preparation, and ensure that the data, personnel, materials and equipment required for construction are in place and meet the requirements; S2: Cable trench excavation: lay out the cable and excavate according to the design requirements, control the slope coefficient and excavation depth, handle the trench base and special conditions, and lay soft soil or fine sand on the trench bottom after excavation; S3: Cable laying: Lay cables in cable trenches by direct burial, control cable spacing, traction, and turning radius, do a good job of cable protection and joint configuration, set up a communication and command system, and insulate or heat the cables during winter construction; S4: Cable intermediate joint / terminal installation. According to the cable type, the cable intermediate joint and terminal are made according to the specific procedures, and the cable is grounded and installed using the grounding method at both ends; S5: Cable test: After the cable is laid, the cable is subjected to insulation resistance test and withstand voltage test; S6: Fireproof sealing / coating, fireproof sealing and coating construction for cable pipe inlets and outlets and specific areas; S7: Concealed acceptance: invite relevant units to conduct concealed acceptance of the cable laying project; S8: Backfilling: After the concealed inspection is qualified, backfilling shall be carried out, compacting shall be done in layers, and protective plates and warning tapes shall be laid; S9: Bury marker stakes at specified locations along the cable path.

2. A construction method for laying a 35KV collector line cable according to claim 1, characterized in that: In the above step S1, the insulation of the cable is measured before laying. When the temperature is lower than 5°C during construction, the cable is insulated 2-3 days in advance.

3. A construction method for laying a 35KV collector line cable according to claim 1, characterized in that: In the above step S2, the base of the cable trench needs to be compacted, and the bottom width should meet the requirement that the bottom of the two side walls is 150 mm away from the cable respectively, and the horizontal clearance between the cables is 250 mm.

4. A construction method for laying a 35KV collector line cable according to claim 1, characterized in that: In the above step S3, the cable is laid by manual traction, and the traction force of the cable is monitored in real time to ensure that it does not exceed the allowable traction force of the cable. The cable is led out from the upper end of the drum, and the turning point meets the cable turning radius requirement.

5. A construction method for laying a 35KV collector line cable according to claim 1, characterized in that: In the above step S4, the cable head production includes stripping the outer sheath, stripping the armor layer, stripping the inner cushion layer, splitting the core wire, welding the ground wire, wrapping the filling glue, fixing the three-finger sleeve, stripping the copper shielding layer, fixing the stress tube, crimping the wire nose, fixing the insulating tube, and fixing the phase color sealing tube.

6. A construction method for laying a 35KV collector line cable according to claim 1, characterized in that: In the above step S6, the fire retardant coating is applied 5-7 times at 1.5m on both sides of the fire blocking point of the cable, and the thickness after drying is ≥1mm.

7. A construction method for laying a 35KV collector line cable according to claim 1, characterized in that: In the above step S8, after backfilling 100mm of soft soil or fine sand on the top of the cable, a concrete protection plate is laid, with one side of the protection plate 50mm wider than the cable sheath. After backfilling 300mm of earth on the top of the protection plate, a cable warning tape is laid directly above each high-voltage cable.

8. A construction method for laying a 35KV collector line cable according to claim 1, characterized in that: In the above step S9, obvious cable marking stakes are set at intervals of 50 meters along the straight line of the cable path and at intervals of 20 meters at bends and cable joints, and the cable stakes are exposed 300 mm above the ground.

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