A plan for sewer reconstruction in Széll Kálmán tér between Széll Kálmán tér 11. and Margit körút 91. and between Krisztina körút 3. and Széll Kálmán tér 15. was completed under the project. The design area is provided with sewerage through a combined system. Within the catchment area of the Kelenföld Pumping Station, it is located on the boundary between the principal sewer main running in Margit körút and the catchment area of Ördögárok, a covered brook. The majority of the area belongs to the catchment area of the principal sewer main running in Margit körút, and the recipient of the collecting sanitary and storm sewage is a 160/200 ‘O’/T sewer starting at the Széna tér corner of Margit körút.
The proposed reconstructed sewer also serves as a recipient for the drainage of the roadway section being reconstructed in Margit körút, Szilágyi Erzsébet fasor and Krisztina körút in connection with the reconstruction of the ground surface in Széll Kálmán tér, as well as is the recipient for the internal sewer network of the square and the building sewers of surrounding buildings.
The sewers concerned have a 63/95 t/b cross-section and are reconstructed in a total length of about 570 linear m. On the basis of consultations with the operator, the design includes the reconstruction by applying a trenchless technology and pipe pulling. A 50/75 t/ÜPE sewer is pulled into the existing 63/95 t/b sewer, and the building sewers are reconstructed in open trenches.
On the section also affecting the tramway closest to Széna tér, unlike the route of the existing sewer, the sewer is reconstructed on a new route due to the reconstruction of the ground surface in Széll Kálmán tér. On this section, according to the plan, a reinforced concrete sewer with a diameter of 80 cm is constructed in part in an open trench and in part without excavation under the tramway, using the microtunnelling process.
The proposed cleaning manholes are connected with a monolithic reinforced concrete structure. At the junction of Szilágyi Erzsébet fasor and Krisztina körút and at the connection point to the recipient of the sewer running from Széna tér on the new route, custom-made reinforced concrete structures are constructed.
The design documentation divides the sewer reconstruction works into two construction phases. The organisation plan of the project was prepared in accordance with the general organisation of the surface reconstruction of Széll Kálmán tér.