Optical cable laying engineering standards

According to the laying method, it can be divided into: aerial optical cable, pipeline optical cable, buried optical cable and underwater optical cable.

The construction process of optical cable lines is complex, and the processes must be properly connected. Because the operating procedures are carried out according to scientific management methods, the project implementation date is planned, and the specific routing location, distance, protection area, etc. are determined.

It plays a role in ensuring that the construction tasks of the project can be completed on time with high quality.

1. Routing retest of optical cable lines 1. Determine the routing direction of the optical cable and select the laying method according to the design requirements.

(Mainly divided into urban, suburban and open areas through on-site survey.

Generally, engineering construction in urban and suburban areas is more complex, while open areas are relatively easier.

Therefore, the project price will vary according to the relevant geographical environment.

) 2. Provide necessary data to determine the distance from the relay section to the other terminal.

3. Approval of technical measures for roadblocks, rivers and other obstacles, and work out the possibility of specific implementation.

4. Carefully observe the topography and landforms, and initially determine the environmental conditions for the location of the line joints.

2. Detection of optical cable quality 3. Laying of optical cables The laying lines must be re-tested according to the route. If changes are necessary under special circumstances, the consent of the competent authority must be obtained in a timely manner.

According to the selected laying method and the difficulty of the project, the positions of construction personnel should be correctly allocated and the responsibilities should be assigned to each person.

1. Aerial optical cables ⑴ Requirements for overhead optical cables: ● There are two main types of aerial optical cables: steel strand-supported and self-supporting.

Our country basically adopts the steel strand support type. This structure is supported or bundled by pole suspension wires.

● The distance between poles of overhead lines is 25~40 meters in urban areas, 40~50 meters in suburbs, and the maximum in other areas is no more than 67 meters.

● The hanging wire of the overhead optical cable should be made of 7/2.2mm galvanized steel strands. For hanging light armored optical cables, 7/2.0mm or /1.8mm steel strands can be used. .

● The sag of the aerial optical cable should consider the elongation produced when the maximum load is applied during and after erection.

● Aerial optical cables can be appropriately extended and retracted on the poles.

● Erect the poles according to the design requirements, place suspension wires or use the original pole path for renovation to meet the specified requirements.

● The clamping spacing of optical cable hooks is required to be 50 cm, and the allowable deviation is no more than ±3 cm.

The optical cables should be hung evenly, the hook pallets should be complete, and hook models of different sizes should be selected for the outer diameters of various optical cables.

A cable table with various hook models is included

⑵ Optical cable suspension wire erection method: ● Use guide pulleys, that is, put the suspension wire into the pre-installed suspension wire trough along the end of one terminal, and install a large pulley on the pole at the other end , after the change, use the wire take-up machine or hoist to tighten the hanging wire.

● When laying the optical cable, a small guide pulley should be installed every 20 to 30 meters, and the pulling rope should be passed through the pulleys in order until it reaches the end of the optical cable to be pulled.

During construction, optical cables are generally pulled several times.

● After the optical cable is pulled, use a hook at one end or several ends to hang the optical cable on the suspension wire at the same time. This is usually used (it is faster and better for engineers to ride a scooter).

Other methods can also be used.

When hanging the line, if it is a long-distance trunk line, considering its certain distance, leave appropriate extra coils to tie up and hang on the pole road, so that the line can be easily restored in special circumstances.

(3) Wall optical cable ● When there is no pole path, wall optical cables can be laid in factories or residential buildings.

● Wall optical cables are mostly used in the construction of communication lines used in factories, mines, enterprises and living quarters.

● Its erection is basically based on the overhead pole path.

2. The pipe optical cable has a standard urban ф90MM pipe hole and can accommodate 3 3~4-inch plastic sub-tubes.

The 1-inch sub-tube is suitable for optical cables with a diameter less than 20MM. For other types of optical cables, appropriate sub-tubes should be selected.

● The sub-tube is prone to distortion during the laying process. When the twist pitch is within 10 meters, the friction between the optical cable and the inner wall of the sub-tube increases, which will bring certain difficulties to the laying of the optical cable. , so the plastic sub-pipes should be laid to avoid distortion.

● The laying of pipeline optical cables must pass through the entrance and exit routes of the manholes. When there are turns, curves, and height differences in the pipeline manholes, guide devices should be configured in a timely manner to reduce the friction of the optical cables and reduce the traction tension of the optical cables.

● A special tool "nylon rod" should be used to pull the optical cable into the sub-tube, and the appropriate engineering and technical personnel can be pulled in line. After the optical cable is pulled, the remaining cables in each manhole will be manually put into the specified position. on the bracket.

For future safety, hoses or PE hoses are generally used for protection and fixed with zip ties.

An appropriate length of coil should be left at the end of the optical cable before hanging on the manhole wall.

Do not soak in water.

3. Buried optical cables ● To lay direct buried optical cables, trenches must be dug first. It is very important to achieve sufficient depth and uniform standards along the line according to different environments.

TrenchingThe standard is generally 1.2 meters for ordinary soil, 1.0 meters for semi-stony soil, and 0.8 meters for quicksand. When crossing railways and highways, 1.2 meters should be added to the bottom of the above ditch. 10CM of fine soil or sand should be added to the bottom of the ditch. The width of the ditch bottom is generally 30CM.

When laying two or more optical cables in the same trench, a 5CM spacing should be maintained between the optical cables.

Steel pipes or rigid plastic pipes should be pre-embedded in sections where the road surface is often under pressure.

When laying optical cables, they should be laid in an "S" shape when encountering slopes, crossing railways, highways and other special areas.

● Directly buried optical cables must take "two prevention" measures ⑴ Lightning protection: Most of the directly buried optical cables use metal parts such as reinforcements, moisture-proof layers and armored layers, which are prone to lightning strikes and serious damage to the optical cables. Communication is interrupted.

Treatment measures: A. Intra-office grounding method B, system grounding method C, laying shielded wire above the optical cable (2) anti-corrosion, anti-rat, etc.