Under the program for the Development of Northern Argentinean Provinces: Infrastructure Water and Sanitation, financed by the Interamerican Development Bank, the Program Execution Unit conducted the bidding process and award of the International Public Tender No. 01/13 for project: Streamlining of Pumping Plant Drive and Effluent Treatment Station - Santiago del Estero whose bid is on 27 November 2013. On held January 13, 2014, the InterAmerican Development Bank (BID) reported no objection to the recommendation for award of contract.
This integrated urban sanitation project involves the expansion of sewage lying over the construction of a sewage liquids treatment plant. It provides for expanding the number of new connections in 14,493 units, which would add to the existing 30,560 units. The length of the extension needed to achieve network is estimated at 425.9 km.
The new pipeline will run from the station EB1 by Dr. Degano, Independencia, Av. Dr. Victor Alcorta heading south to the main drainage canal south street that runs through Los Lapachos. From there change direction by 90°, to take on the left side to its in the Viano channel mouth to cross it and continue along the left side of channel until turn at 90° to go to inlet of future treatment plant.
This is a line 4250 meters of pipes that will be subjected to a maximum pressure of 3 kg/cm², for which the use of a hydraulic line of 1100 mm inner diameter and 6 kg/cm² nominal design pressure was determined.
The constructor consortium called Krah America Latina to develop an alternative to the original offer, which was conceived in ductile iron or HDPE ISO4427, with butt fusion joint; but both alternatives were not adapted to the limitations of the work, in the first case because it is imported goods, expensive and very long delivery times supplies and in the second, of hard work in the trench, to be carried by urban areas and collapsible soils and high water tables.
For this, Krah America Latina made two offers, one using the PE/GF technology and the other with PE100 using the DIN/PAS 1065: 2007 standard. For this he made the following comparison:
After hard negotiations, the use of the first alternative was decided and went on to perform the mechanical and structural design of the pipe.
While main pipeline will work at a maximum pressure of 3 kg/cm², the conditions of employment demanded that the pipes had 6 kg/cm² maximum allowable design pressure. So we proceeded to perform mechanical calculations according to the following table:
All calculations were based on ISO 161 standard. At the same time, structural calculation was performed. For this Marston-Spangler theory stated in recommendations of AWWA M55 standard is used; then the calculation is added box.
Finally, the pipes were designed under these concepts and specifications and conditions are as follows:
The work began in October 2014 and is scheduled for completion by September 2015. Shipments are made from Krah America Latina factory located in Buenos Aires and travel more than 1000 km to reach the work site in northern Argentina.
All joints were made using the unique system of electrofusion by Krah. Training courses were held and operators of construction consortium were prepared; regular visits to monitor the process are also performed.
At the date of issuance of this report, the work is in full swing, following the planned schedules.