What is a direct buried optical cable? Direct buried optical cable is a communication optical cable laying method.
This kind of optical cable is armored with steel strips or steel wires on the outside and is directly buried underground. It is required to resist external mechanical damage and prevent soil corrosion.
1. The cross-sectional size of the trench for trenching should be in accordance with the requirements of the construction drawings. The bottom width varies with the number of optical cables. Generally, it is 1 to 2 optical cables. The bottom width of the trench is 30-1000px; for 3 optical cables , the trench bottom width is 1375px; the trench bottom width of 4 optical cables is 1625px.
The width of the trench bottom is approximately the bottom width + 0.1 times the burial depth.
Optical cables laid in the same trench must not cross or overlap. The optical cable trenches on the two straight sections must be as straight as possible. When there are obstacles on the straight line, they can be bypassed, but after bypassing the obstacles, they should return to It turns out that on a straight line, the bending radius of the turning section is no less than 20m.
When laying optical cables with a slope greater than 20 degrees and a slope length greater than 330m, it should be laid in an S shape or handled according to design requirements.
2. Ditch bottom treatment: The bottom of the ditch in general areas should be filled with fine soil or sand and compacted. After tamping, the thickness is about 250px; in areas with weathered stone and gravel, about 125px thick mortar should be laid first, and then filled with fine stones or sand. stones to ensure that the optical cable is not scratched by the sharp edges of gravel; if the outer sheath of the optical cable is steel wire armored, mortar can be omitted; in areas with soft soil that is prone to collapse, wooden piles and wooden blocks can be used as temporary protection wall protection.
3. The laying and direct burial of optical cables are mostly done in the wild. Mechanical laying can only be used when the route is along the road. Mechanical laying is done by trucks or flat cars with reeling lines for traction, and is first carried out by a crane. Or lift the forklift to load the optical cable drum into the vehicle and then remove the small cutting plate or metal drum cover on the optical cable drum. The commander should check that the preparations are in place before starting the deployment.
The motor vehicle should move forward slowly, and at the same time, use human hands to drag the optical cable out of the cable drum, place it gently on the edge of the ditch, release it for 20m, and then put it into the ditch manually.
There are currently very few conditions for mechanical traction for direct burial laying. It is generally laid manually. There are two ways of manual laying, one is the straight-line shoulder-carrying method (note that no matter what method is used for laying, It is not allowed to drag optical cables on the ground), the distance between personnel is small, and the commanders act in a unified manner ; The other method is manual lifting. First, the optical cables are coiled into a figure-8 shape, and each 2KM optical cable is piled into 10 figure-8 shapes. Each group is bundled with 6 groups with leather wires. Each group has 4 people to lift the cables, and one person in each group. Coordination, the front of the first group is guided by two people. During deployment, each group lifts up and moves forward along the trench under unified command.
