Trade Journals for the Concrete Industry

In the City of Zurich/Switzerland an almost hundred year old sewer pipeline had to be replaced by a new 294 m long reinforced concrete pipe line with an inner diameter of 1200 mm. Due to narrow spaces and heavy traffic conditions Microtunneling technique showed to be the most suitable technique and has been chosen by the owner and the designing engineer. Geometrical boundary conditions and existing underground utilities only allowed a curved alignment with the small radius of 125 m. Applying the Hydraulic Joint system the demanding alignment could have been driven with regular pipe length of 3 m with no significant reduction of the jacking speed. This paper gives in its first part a short introduction in the theory and the way of function of the Hydraulic Joint pressure transmission ring. In the second part it shows the development of the project between the involved parties and the most significant experiences made on this exceptional job.