Trenchless Technologies

Trenchless Technologies is a general term used for a group of technologies for new pipelines construction or rehabilitation of existing pipelines with minimum or without any excavations. These technologies provide possibilities for cheaper and faster installation or rehabilitation of gas and water lines, sewer lines etc. without limiting of the traffic, with minimum risks for the existing infrastructure in the area, with minimum environmental impact, practically in any soils and under various obstacles, like roads, railways, buildings, rivers, canals, at large depths etc.


2020 “Stroitelna Mehanizatsia” AD completed the first of four drillings with a micro-tunnelling machine in the aim to build a pipeline during the reconstruction of the tailings dam of “Aurubis-Bulgaria”. The new pipeline will have diameters of 1200 mm and 1400 mm and a total length of about 600 m. The tunnelling machine that executed the work is owned by “Stroitelna Mehanizatsia” AD.

2019 The company completed the rehabilitation of part of a sewer main in the center of the city of Ifrane in Morocco. This is a very famous ski resort in North Africa, located at 1650 meters above sea level and is one of the ten cleanest cities in the world. One of the residences of the King of Morocco is situated close to the mountain settlement, as well as the country's most elite higher education institution, built in 1990: The American University. “Stroitelna Mehanizatsia” AD rehabilitated a sewer collector with a diameter of 500 mm and a total length of 124 meters, using the technology “Cured in place with hardening of the liner with UV [CIPP –UV]”. The existing inspection shafts were used to access the pipe.

2018 The company performed the rehabilitation of the sewerage network in the medina [the medieval part] of the Moroccan city of Boujaad, which is under the UNESCO’s protection. The medina is characterized by narrow cobbled streets, buildings located close to each other and a large flow of people, especially during the tourist season. Some of the pipes in this part of the city are more than a century old. Within three months, the existing gravity collector with diameters from 200 mm to 400 mm and a total length of about 700 meters was rehabilitated, using the technology “Cured in place with hardening of the liner with UV [CIPP –UV]”.

2017 “Stroitelna Mehanizatsia” AD performed the rehabilitation of an existing sewer collector for domestic and rainwater in Sofia, located under the Blvd. “Petko U.Todorov”. The rehabilitation was performed using the technology “Cured in place with hardening of the liner with UV [CIPP – UV]”. This was the first application of the method in Bulgaria. The installation of the lining on the sewer concrete pipe, with egg-shaped profile and the following parameters: section 50/70 cm and length 146 m, was carried out through the existing inspection shafts, without any violations of the surrounding infrastructure.

2014 The company performed the rehabilitation of large diameter pipes in Thermal Power Plant Zhezkazgan, Republic of Kazakhstan. The applied technology is "Cured in place [CIPP]” and the method for inversion was with "Water Tower". The project was highly praised by the International Society for Trenchless Technology. For its implementation “Stroitelna Mehanizatsia” AD was awarded the most prestigious international award No-Dig 2015.

2011 The company introduced in Bulgaria the “Spirally Wound Pipe technology [SPR]”, used for rehabilitation of aged and structurally damaged gravity pipes. The first project implemented in Bulgaria by using the above technology, the company completed in Plovdiv where an aged sewer collector in a very bad condition (where a real danger for road collapse existed) was rehabilitated. Immediately after, another project using SPR technology started in the copper refinery “Aurubis” situated closely to the town of Pirdop. “Stroitelna Mehanizatsia” AD rehabilitated more than one kilometer of sewer pipes with this technology.

2010 “Stroitelna Mehanizatsia” AD implemented one of the most complex rehabilitation projects in the world by CIPP technology for water main in Sofia with impressive parameters: diameter of 1220 mm and a total length of 360 m. Completed in early 2011, the project won the most prestigious award of the International Society for Trenchless Technology, the No-Dig Award for "Project of 2011"

2010 “Stroitelna Mehanizatsia” AD, performed near a kilometer of Horizontal Directional Drilling under rivers and canals for installation of a gas pipeline connecting the Serbian gas storage "Banatski Dvor" with the gas transmission network of Serbia.

2009 The company implemented in Bulgaria the trenchless technology "Cured in place [CIPP]” for rehabilitation of obsolete pipelines. The beginning was set with the implementation of the rehabilitation of a water main in the town of Lovech, with a total length of the pipes 800 m and diameters from 400 mm to 600 mm.

2008 The first drilling in a solid rock became a fact in Bulgaria. The contractor Stroitelna Mehanizatsia AD carried out a drilling near the town of Dzhebel by using a horizontal directional drilling machine purchased specially for this purpose.

2008 The company has carried out a series of complex drillings during the construction of the gas pipeline Iran-Italy in the area of the Komotini town, Greece. By means of Horizontal Directional Drilling technology, “Stroitelna Mehanizatsia” AD, installed casing steel pipes with diameter 1600 mm under busy roads and railroads and under the highway "Via Egnatia".

2006 The company implemented the Microtunnelling technology for the first time in Bulgaria. As a member of the Consortium “Microtunnelling - Bulgaria” the company used the above technology and installed sewer pipes during the construction of subway Station No.8 near Sofia University. In 2010 the company was the main contractor for a project implementing the same technology. With its own microtunnelling machine “Stroitelna Mehanizatsia” AD built a culvert with a diameter of 2400 mm, passing under the Ring-road of the town of Plovdiv and also under a double railway line Sofia-Bourgas.  

2004 “Stroitelna Mehanizatsia” AD implemented the first drilling in Bulgaria, under the bed of a big river: an installation of a water-main under Maritsa river by using Horizontal Directional Drilling technology. The company has gained extensive experience in such projects. Up to mow, pipes with total length of over 1,5 km have been installed only under Maritsa river.