The laying method has the advantages of large capacity, and generally adopts a concrete structure. The cable is laid in the air, and the cable has a large current carrying capacity, and can be entered into a small or small machine, a book cable structure, and the outer cable protection is excellent.
For fully enclosed cable structures, tunnels generally have better monitoring equipment. The detection of temperature, humidity and gas is perfect, and the requirements for anti-theft, waterproof and fireproofing are basically guaranteed.
Advantages of tunnel laying: The tunnel laying method is safe for high-voltage power cables, and the monitoring facilities are perfect. Under certain current-carrying requirements, power cables with smaller cross-sections can be selected to save costs.
Disadvantages of tunnel laying: The tunnel has a large open area, which has a great impact on municipalities such as traffic and shops. Especially in urban densely populated areas, construction protection needs to be safe and reliable, and the cost of dark excavation is high. Construction in the city.
According to the long-term development, the use of tunnels is generally 100 years. According to the current investment considerations, the cost of tunnels for 100 years is more economical and reliable than other installations, but the investment in the previous period is relatively large. This requires multi-party coordination to realize the 100-year plan for power companies.
For the four common high-voltage power cable laying methods, the direct burial and pipe laying methods have small excavation face, low investment, poor protection under direct burial mode, and large current loss in pipe laying mode; cable trench and tunnel laying mode The excavation surface is larger and the investment is larger, but the outer protection is better and the current loss is smaller.
If it is only a short-term project and the funds are tight, the cable can be laid by the combination of the pipe and the cable trench to meet the needs of the current ten to twenty years. If the current funds are relatively abundant, the high-voltage power cable should be laid by tunnel laying. To meet the power needs of the next century.
In newly built or rebuilt roads where the pipe position is tight and there are many conflicts with other pipelines, the open cut pipe (referred to as the pipe exhaust pipe) should be preferentially arranged according to the number of planned circuits, and a small number of sections that cannot be used for open cut construction can be opened. Digging pipe (referred to as pull pipe) or non-excavation pipe jack (referred to as pipe jacking).