Hobas.nl

July 2011
PipeLine
Content
1 | h - A Single Source Solution for Utrecht’s Sewers, NL
3 | Long-Lasting Pipes for the Eternal City, IT
h – A Single Source Solution
for Utrecht’s Sewers
Sewer Renovation Project in the Netherlands Utrecht, the 4th largest city of the Netherlands, counts about 312,000 inhabitants and is an important node regarding roads, rail- and wa- terways. Its district Ondiep in the northwest of the city owes its existence to the river Vecht of which the largest bend had silted up over the years and now provides living space for approximately It is beneath this district that an important sewer main DN 1800 carrying the wastewater from most of the city to the adjacent wastewater treatment plant was found dete- riorated and needed renovation. Expected impacts on the urban district in the course of the works prompted the city to inspect adjacent sewers for possibly additional renova- tion so that construction works would affect the urban surroundings once only. An approximately 50 meter-long section of egg-shaped concrete sewer was indeed found to be in insufficient state and therefore included in the renovation plans. The extended project presented itself demanding regarding the multitude of required accesso- ries in addition to standard pipe material. During construc- tion works on the main for instance, the sewage disposal of course had to be maintained over a provisional pipe for the time the works on the main take place. Moreover, instal ation works had to be accomplished in shortest time possible so as to keep the necessary disturbances to the As for many things however, well begun is half done and find- ing the suitable construction material often facilitates and speeds up implementation considerably. Utrecht found its material answer in HOBAS Products which presented a single source solution for a great part of the project. Three HOBAS Shafts with GRP Flanges were laminated onto the existing main and equipped with pumps to divert the E Engineering GmbH | Pischeldorfer Str. 128 | 9020 Klagenfurt | Austria
h PipeLine | July 2011 | Page 02
wastewater into a provisional pipeline. Once the renovation works were completed, they were covered with GRP Blind Flanges for future use. HOBAS Products were further utilized for the renovation and replacement of old concrete shafts. Due to the restricted space on site DN 1500 GRP Pipes were employed between these structures and their relatively thin wal s and low weight facilitated the instal ation. Ma-sonry couplings, roughened pipe ends and FWC couplings make sure that the system remains tight to all ends. Last but not least, HOBAS NC Line Profiles, each 1.7 m long and 870/1325 mm in diameter, were used to reline the egg-shaped concrete sewer branch. Their easy and therefore fast instal ation (14 profiles per day) and struc-tural and hydraulic benefits as well as a product lifetime up to 100 years tipped the scale for the client to opt for GRP here as wel . To the benefit of the client, HOBAS Benelux resorts not only to the experience but also the material employed 2010 - 2011
for countless projects realized around the globe by the HOBAS Group: In this case, the neces- Shafts, pipes, various
sary mold for adapting the GRP Profiles to the components
old structure could be reused from one of the countless non-circular pipe rehabilitation proj- ects realized in Europe, resulting in further cost NC Profile 870/1325 mm
Pressure class
PN 1
Stiffness class
SN 5000
Instal ation method
Open trench,
relining
Client
City of Utrecht
Engineering
Grontmij
Constructor
Van Boekel, Boshuis,
GMB
Advantages
Easy and therefore fast
installation, light weight,
relatively thin walls,
optimal structural pro-
perties, long product life,
single source solution.

Source: http://www.hobas.nl/fileadmin/Daten/REFERENCES/World/Documents/2011/2011_07_NL.pdf