Outdoor optical cable laying methods and requirements

There are three common laying methods for outdoor optical cables, namely: pipeline laying, direct burial laying and overhead laying. The following is a detailed explanation of the laying methods and requirements of these three laying methods.

1. Pipe laying

Pipe laying is a widely used method in optical cable laying engineering, and its laying must meet the following requirements:

1. The optical cable should be put through the sub-holes in the tube hole before laying. The optical cable should be inserted into the same color sub-tube in 1 hole, and the unused sub-tube mouth should be protected with a plug.

2. Considering that the laying process is all manual operation, in order to reduce the loss of optical cable joints, the pipe optical cable manufacturer should adopt the entire laying method.

3. During the laying process, the traction force during laying should be reduced as much as possible. The entire optical cable is laid from the middle to both sides, and personnel are arranged in each manhole to assist in the middle traction.

4. The hole position of the optical cable should meet the requirements of the design drawings, and the pipe hole must be cleaned before laying the pipeline optical cable. The sub-hole tube should expose about 15cm of the remaining length of the tube hole in the hand hole.

5. The interface between the sub-pipe in the hand hole and the plastic textile network pipe is wrapped with PVC tape to avoid the infiltration of sand.

6. When the optical cable is installed in the man (hand) hole, if there is a supporting plate in the hand hole, the optical cable is fixed on the supporting plate. If there is no supporting plate in the hand hole, the optical cable should be fixed on the expansion bolt. The mouth of the hook is required to be downward.

7. The optical cable should not be bent within 15cm of the outlet hole.

8. Plastic signs are used in each hand hole and on the optical cable and ODF rack in the computer room to show the difference.

9. The optical cable duct and the power duct must be separated by at least 8cm thick concrete or 30cm thick compacted soil layer.

2. Direct buried laying

If there are no conditions for aerial use under the laying conditions and the laying distance is long, direct burial laying is generally used, and direct burial laying should meet the following requirements:

1. Avoid areas with strong acid and alkali corrosion or severe chemical corrosion; if there are no corresponding protective measures, avoid termite-hazardous areas and areas affected by heat sources or areas that are prone to external damage.

2. The optical cable should be laid in a trench, and the surrounding area of the optical cable should be covered with soft soil or sand layer with a thickness not less than 100mm.

3. The entire length of the optical cable should be covered with a protective plate with a width not less than 50mm on both sides of the optical cable. The protective plate should be made of concrete.

4. The laying position is in places where excavation is frequent, such as urban access roads, and a striking marking belt can be laid on the upper layer of the protection board.

5. At the laying position located in the suburbs or in the open area, obvious azimuth signs or stakes should be erected at the straight line interval of about 100mm along the optical cable path, at the turning point or at the joint.

6. When laying in non-frozen soil areas, the cable sheath to the foundation of the underground structure shall not be less than 0.3m, and the depth from the cable sheath to the ground shall not be less than 0.7m; when it is located on the roadway or cultivated underground, it shall be properly deepened, and should not be less than 1m.

7. When laying in permafrost areas, it should be buried below the permafrost layer. When it cannot be buried deeply, it can be buried in dry permafrost layer with good soil drainage or backfill soil, and other measures to prevent damage to the optical cable can also be taken. .

8. When the directly buried optical cable line crosses the railway, highway or street, it should wear a protective tube, and the protection range should exceed 0.5m above the roadbed, both sides of the street and the side of the drainage ditch.

9. When the optical cable laid directly buried is introduced into the structure, a protective tube should be installed at the penetrating slope hole, and the tube mouth should be blocked by water blocking.

10. The clear distance between the connector of the directly buried optical cable and the adjacent optical cable shall not be less than 0.25m; the joint positions of the parallel optical cables should be staggered from each other, and the clear distance shall not be less than 0.5m; the position of the connector on the slope terrain shall be horizontal; for important circuits It is advisable to leave a spare way to lay the optical cable at the local section starting from about 1000mm on both sides.

3. Overhead laying

Aerial laying can exist between buildings and buildings, between buildings and utility poles, and between utility poles and utility poles. The actual operation depends on the situation at that time. When there are electric poles between the buildings, steel wire ropes can be erected between the buildings and the electric poles, and the optical cables can be tied to the steel wire ropes; if there are no electric poles between the buildings, but the distance between the two buildings is about 50m, Optical cables can also be erected directly between buildings through steel cables, and the laying requirements are as follows:

1. When laying the optical cable in the flat environment in the aerial way, use the hook to hang it; when laying the optical cable in the mountain or steep slope, use the binding method to lay the optical cable. The optical cable joint should choose a straight pole position that is easy to maintain, and the reserved optical cable should be fixed on the pole with the reserved bracket.

2. The optical cable of the overhead pole road is required to make a U-shaped telescopic bend every 3 to 5 poles, and about 15m is reserved for every 1km.

3. Lead the overhead (wall) optical cable with galvanized steel pipe protection, and the nozzle should be blocked with fireproof mud.

4. Aerial optical cables should hang optical cable warning signs every 4 bars or in special areas such as crossing roads, rivers, and bridges.

5. A three-prong protective tube should be added at the intersection of the empty suspension line and the power line for protection, and the extension of each end should not be less than 1m.

6. The pull wires of electric poles near the road should be covered with luminous rods, and the length is 2m.

7. In order to prevent the induced current from the suspension wire from injuring people, each pole pull wire is required to be electrically connected to the suspension wire, each pull wire position should be installed with a pull wire ground wire, and the suspension wire is required to be directly connected with a lining ring and grounded directly at the terminal.

8.The overhead optical cable is usually 3m above the ground. When entering the building, it must pass through the U-shaped steel protective sleeve on the outer wall of the building, and then extend downward or upward. The aperture of the optical cable entrance is generally 5cm.