Nowadays, the development of urban infrastructure requires not only efficiency, but also security. When we are considering issues related to electricity, the intersections of cable lines with underground infrastructure become key. The introduction of underground energy installations is not only an aesthetic solution, but also significantly improves resistance to weather conditions and minimizes the risk of damage. In this article, we will look at how modern design and technological solutions can ensure the safety and reliability of this key element of urban energy infrastructure.
How are intersections with an open excavation method?
The open excavation method is one of the commonly used techniques when performing intersections of cable lines and fiber optic cables with existing underground infrastructure. It guarantees not only accuracy and precision during laying, but also meets high standards of safety and operational protection.
The basic assumption of this method is to place NN cables, fiber optic cables and possible ECC cables (responsible for shielding continuity) in separate culverts, i.e. cover pipes. Compliance with appropriate vertical distances is crucial: a cord with a NN cable from a crossed object should be at least 0.7 meters, while the culvert with fiber optic cable (fiber optic sewage) at least 0.5 meters. For connections, it is necessary to equip such as an ironing head, but the distances between the cables and the infrastructure surrounding them are also important.
In the case of crossing with pipelines of heating, water supply, sewage or gas networks with non -fallen gases, minimal vertical distances should be further increased by the diameter of the crossed pipeline. However, in the case of pipelines with gases and flammable liquids, minimal distances should be agreed with the owner of the pipeline, while maintaining safe standards.
In addition, to ensure operational safety, the vertical distance of the culvert with the NN cable and fiber optic cable from the head of the railway traction rail or the upper road area should be at least 1.5 meters. However, the vertical distance of the culvert with the NN cable from the bottom of the drainage ditch should be at least 1.3 meters, and the culvert with a fiber optic cable of at least 0.8 meters, which provides additional protection against potential damage.
The use of an open excavation method not only enables accurate and safe execution of the intersection of cable lines with existing infrastructure, but also provides durability and minimizes the risk of failure during operation. Thanks to detailed planning and compliance with technical standards, it is possible to effectively integrate various types of underground infrastructure in a way that not only meets safety requirements, but also contributes to the efficiency and reliability of the energy system. One of the advantages of cable lines is lower failure rate. Overhead lines still, despite the use of such elements as the swimming or suspension, are still more vulnerable to failures.
Controlled and microtuneling drilling
The method of controlled drilling and microtuneling, used when laying underground cables, is an advanced technology that allows you to exceed existing underground objects. A key element of this process is precise planning and compliance with technical standards, which ensure not only effectiveness, but also the safety of operation.
During the intersection using the controlled drilling or microtunering method, it is important to maintain the appropriate vertical distances between the culverts with the NN cable and culverts with fiber optic cable (fiber optic sewage system) and the crossed object. According to the standards, the minimum distance is 1 meter, however, in the case of crossing with pipelines of heating, water supply, sewage or gas networks with non -fallen gases, this distance should be additionally increased by the diameter of the crossed pipeline. However, in the case of pipelines with gases and flammable liquids, minimal distances must be agreed with the owner of the pipeline, while maintaining safety and technical norms.
Operation safety is also provided through an adequate vertical distance of the culvert with a NN cable and fiber optic cable from the level of railway traction rail and the upper road, which is at least 1.5 meters. In addition, the distance from the bottom of the drainage ditch for the culvert with the NN cable and fiber optic cable should be at least 1.3 meters, which minimizes the risk of damage as a result of environmental conditions. When laying, equipment such as trailers for transporting cable drums are used to avoid cable damage already at the laying level.
Safe culvert laying
When safe culverts, i.e. cover pipes intended for exceeding the existing underground infrastructure, precise planning and compliance with safety standards play a key role. According to the technical requirements, the culverts should go beyond the outline of various infrastructure elements to ensure not only reliability, but also to minimize the risk of damage.
When laying culverts, it should be taken into account that they should protrude at least 1 meter on each side of the intersection above the outline of foreign underground infrastructure and the edge of the road. For active tracks intended for traffic of rail vehicles, the minimum distance should be 5 meters on each side of the intersection, which protects against possible interference in railway traffic.
In addition, culverts should protrude at least 3 meters on each side of the intersection above the outline of building objects, which minimizes the risk of damage to construction infrastructure. In the case of drainage ditches, a distance of at least 1 meter, counting from the upper edge of the ditch, is recommended, while at the shoreline of watercourses, at least 1 meter from the flood condition should be taken into account, in accordance with the current requirements.
The final culvert lengths can be adapted to the specific local regulations or the requirements of the infrastructure management, which may require larger intervals to ensure maximum security and functionality of the entire underground urban infrastructure system. Thanks to the thorough compliance with these standards, it is possible to effectively and safely perform intersections and minimize the risk of potential damage.
