How Vertical Vessels Are
Vertical vessels are structures which contain and usually process fluids and span more in the vertical direction. Many will be familiar with the fractionating column used in refineries, but this is only one of the many shapes of vertical vessels. During the design of connection bolts and foundation, the wind load on vertical vessels is important.
Uses of Vertical Vessels
- Food and beverage industry
- Chemical industry
- Pharmaceutical industry
- Plastics industry
- Oil and fuel industry
- Heating and cooling systems
Design of Foundation for Vertical Vessels
For a civil engineer, the properties of a vertical vessel are needed in a bid to commence designing the foundation. The actual design of a vertical vessel is more related to mechanical engineering; however, the outcome of the data is used by structural engineers to carry out support design.
Methods for vertical vessel foundation design:
- Manual calculation approach
- Computer aided design approach
Onshore Structural Design – Step by Step Calculations provides details about how to design vertical vessels through manual calculations. While computer aided design approach can be done with the use of STAAD Foundation.
Although STAAD Foundation is an easy to use application for vertical vessel design; however, the actual values to be input can only be obtained from the preliminary steps of the manual calculation approach.
Foundation Shape and Attributes
The foundation of a vertical vessel is composed basically of two main parts; the pedestal and the footing.
Pedestal: The pedestal is the concrete block in direct contact below the vertical vessel and transfers load to the soil through the footing. Either round, square or octagonal shapes are used for pedestals. Depending on the availability of forms (formwork). Pedestals that support vertical vessels which are less than 1.7m – 1.8m are to be square or round in shape while those above 1.8m are to be octagonal.
Reinforcements: The reinforcements required for the pedestal are for the pedestal shape and for dowels.
Anchorage: Anchorage is the depth or length of embedment of reinforcements within a concrete section that will ensure sufficient pulling strength between the bond of concrete and the reinforcing bars. This factor is key in determining the minimum depth of the pedestal or the footing itself.
Footing: The design of a rectangular footing is straight forward as against octagonal shaped footings. The latter requires conversion between octagonal and rectangular shaped sections during the calculation of shear, moment and other parameters.
Below is the approach to design of support for Vertical Vessel with the use of STAAD Foundation.