The basaltics rocks of the Alto Parana Formation impose the geology of the construction site of the "Exportation Highway", in a region located on the south east of the Republic of Paraguay, near Argentina and Brazil. The project includes slopes of variable height, lower than 30m. The field tests with rotary drilling were done assuming the design hypotheses and the safety factor of the excavation slopes was estimated. During the execution, a geotechnical mapping will be carried out to confirm and verify the assumed criteria.
Exportation Highway from Natalio (Itapua) to Cedrales (Alto Parana), is 150km long -parallel to the Parana River- and is destined to be in the axis of the area's development. Section II of the Exportation Highway is located in the Northwest sector of the Itapua Department, which represent various cross sections of basaltic rock, being the main one located between Stations 95+ 750 to 96+ 100 or variable height (lower than 30m).
The study describes the following activities:
– Rotary drilling campaign destined for geotechnical approach, from rock cores obtained along-side the highway axis.
– Rock mass classification.
– Definition values for geotechnical parameters for the calculation.
– Bench and slope stability analysis.
In the Parana basin there are more than 60 hydropowers built, including Itaipu and Yacyreta, thousands of kilometers of highways and a great number of bridges.
The region of interest is located in the Parana Basin, with 1,600,000 km2 which covers parts of Brazil, Paraguay, Argentina and Uruguay. The site where the highway project was implemented is located on the occidental side of the basin, in Paraguayan territory.
The basaltic rocks are of the Mesozoic Era and Cretacic Period, due to basaltic lava breccia. It is of the lithologic type that can show three types of residual soil, because it is formed by basaltic breccia, dense basalt and amygdaloidal vesicular basalt.
