The structural design of onshore facilities is intricate due to the dependence of the structural engineer on experience, past projects, several internal/external stakeholders for parameters for the design and different codes of practice. For example, if an engineer is to design a vertical vessel, they will require the weight, wind load, bolt positions and size of the vessel from a mechanical engineering company prior to his commencement of the design of the pedestal and footing.

• General Overview of Proposed Plant facility
  • The first stage in the design is obtaining of Layout drawings provided by client and then the structural engineer commences preliminary sizing. This they do by resorting to past projects, literature and the requests of the clients and engineering team.

• Features to be designed
  • Pipe Rack
    • What is a pipe rack and its uses? What is considered in the design?
      1. Pipe racks are the basic facility feature of industrial facilities as they support pipes, cable trays and other such utilities.
      2. Some parameters considered in the design are:
         • The sizes of the pipes to be carried
         • The total length of utilities to be supported
         • The maximum possible span of pipes and cable trays between supports
         • The maximum deflection and movement of the structure and parts
    • The following are the steps to take while designing the pipe rack
      1. Obtaining of the layout of the pipe rack from the project engineering managers
      2. Configuration of the structure
      3. Estimation of loading from pipes, cable trays and other equipment attachments on the beams and other supports
      4. Determination of other loads in accordance with relevant codes
         • Dead loads, live, wind, earthquake etc.
      5. Placement of loads on the structure and generation of load combinations
      6. Analyzing the structure and designing the members

• Horizontal Vessel
  • What are horizontal vessels and their uses? What is considered in the design?
    1. Horizontal vessels are structures which contain and usually process fluids and span more in the horizontal direction
    2. Some parameters considered in the design of the footing of the supports are:
       • The sizes of the vessel to be carried
       • The likely purpose of the vessel, i.e. heat exchanger, oil separator etc.
       • Properties of the selected horizontal vessel
  • The following are the steps to take while designing the foundation of a horizontal vessel
    1. Obtaining of the template of the saddle and other dimensions of the horizontal vessel from the manufacturer
    2. Configuration of the footing positions
    3. Estimation of loading from the vessel(s), pipes, and other equipment attachments
    4. Determination of other loads in accordance with relevant codes
       • Dead loads, live, wind, earthquake, Thermal, Bundle Pull etc.
    5. Designing the steel slide plate, pier & sizing, footing sizing and design
    6. Designing of footing based on different load cases generated to obtain the most adverse footing condition and factor of safety.

• Vertical Vessel
  • What are vertical vessels and their uses? What is considered in the design?
    1. Vertical vessels are structures which contain and usually process fluids and span more in the vertical direction. They could also accommodate human traffic
    2. Some parameters considered in the design of the footing of the supports are:
       • The sizes of the vessel to be carried
       • The likely purpose of the vessel
       • Properties of the selected vertical vessel
  • The following are the steps to take while designing the foundation of a vertical vessel
    1. Obtaining of the template dimensions of the bottom plate support of the vertical vessel from the manufacturer
    2. Selection of footing shape
    3. Estimation of loading from the vessel(s), pipes, and other equipment attachments
    4. Determination of other loads in accordance with relevant codes
       • Dead loads, live, wind, earthquake, Thermal, etc.
    5. Designing the pedestal, footing, or other type of foundation
    6. Designing of footing based on different load cases generated to obtain the most adverse footing condition and factor of safety.

• Storage Tank
  • What are storage tanks and their uses? What is considered in the design?
    1. For the purpose of this literature and scope, Storage tanks are large usually cylindrical above ground tanks made of metal or concrete for the storage of fluids. They also accommodate human traffic.
    2. Some parameters considered in the design of the storage tank and foundation are:
       • The required capacity of storage
       • The purpose of the storage tank
       • Overfill and height characteristics of the tank
  • The following are the steps to take while designing the tank body and the foundation
    1. Obtaining of the capacity and overfill level of the tank
    2. Selection of the type of roof
    3. Determination of thickness of the shell (body) and the roof
    4. Estimation of loading from the stored fluid
    5. Determination of other loads in accordance with relevant codes
       • Dead loads, live, wind, earthquake, Thermal, etc.
    6. Designing of the bottom plate thickness
    7. Designing of soil bearing of the bottom of the tank. Designing of tank wall supporting beam and other types of foundation support.

Preview of Onshore Structural Design – Step by Step Calculations

Onshore Structural Design – Step by Step Calculations has covered the complete steps for the design in a summarized manner

• This book also provides structural design calculations for each of the basic facility features
  • It contains line by line references to codes, and instruction notes
  • The book comprises of design calculations generated manually and with software. Thus, the steps by hand can be followed as well as that using a computer programme

https://www.amazon.com/dp/B08Z3QPNP5

The design of onshore structural features follows standards which must be strictly adhered to. The book by Mohamed El-Reedy, Onshore Structural Design Calculations will provide a complete view of the intricacies in these kinds of designs. Here is the link to his book.

https://www.amazon.com/Onshore-Structural-Design-Calculations-Processing/dp/0081019440