The scope of work is the study and design of refinery infrastructures for country of Middle East for two different Units. Specifically, the project is about steel structures-platforms which support pipelines & cable trays at multiple levels. Furthermore, platforms serve the accessibility from the personnel for operation and maintenance purposes. The present project also includes the structural design of the foundations of vertical vessels. Steel platforms are made by steel profiles as per AISC and their foundations consist of single footings or footings with two pedestals from reinforced concrete as per ACI. The dimensions of the vertical vessels are the following: a) diameter which varies from 0.50 to 3.0m and b) height from 2m to 22m. Their foundation system consists of reinforced concrete octagonal pedestals and isolated octagonal footings, as per ACI. The load evaluation, the dimensioning and check verification of all structures have been made according to the provisions of the American Code ASCE 10. The design of the steel structures was implemented at STAAD Pro software of Bentley company, whereas the base plates were designed at IDEA StatiCA.