"Dismantling of metal walkways, reinforced concrete slabs and other metal elements via rope access - Vacha Dam"
"National Electricity Company" EAD
Vacha Dam
Dismantling of metal structures and elements in expansion joints – 11,337 kg
Dismantling of reinforced concrete slabs in expansion joints – 30,150 kg
Dismantling of metal brackets up to 5 m from the base of an expansion joint – 1,310 kg
Dismantling of metal bundles in hard-to-reach areas around walkways at a distance of ±8.0 m above/below the walkway – 3,940 kg
Dismantling of metal supports from old stairs in joints 8–9, 13–14, 14–15, 16–17, 20–21 and 21–22 along the height of the expansion joints – 548 kg
Transport and disposal of dismantled metal elements – 17,135 kg
The project includes the dismantling of corroded metal structures, reinforced concrete slabs and other metal elements located in 15 expansion joints of the Vacha dam wall. The wall is concrete-gravity and represents the highest dam wall in Bulgaria, with a height of 144.5 m and a crown length of 420 m.
The dismantling activities include the removal of old metal walkways and concrete slabs, cutting out protruding metal elements, anchors and supports from old stairs. Due to the impossibility of using lifting equipment, as well as the economic and technical inexpediency of building scaffolding, all works were performed using the alpine method, via rope access, by qualified and certified technicians of Vertical Group.
The works were carried out at heights between 60 and 90 meters above the bottom of the individual joints, depending on their geometry. Access was ensured by constructing anchor systems, ropeways and safety routes that met all safety requirements for working at height.
The dismantling of the metal walkways was carried out by gas flame cutting, and the individual elements were transported from the joints to the control galleries on the wall by means of trolley ropes and pulley systems, allowing for precise and controlled removal of heavy loads in difficult-to-reach environments.
The construction of the Vucha hydroelectric power station began in August 1968 and was completed in June 1975. Some of the structures to be removed remained from the initial stage of construction and over time have become heavily corroded, creating a real risk to the safety of the operating personnel servicing the facility on a daily basis.
