The civil engineering building project must first start with a one on one meeting with the client. This is the business part of civil engineering. The engineer uses all of his knowledge in engineering sciences and mathematics to impress the client. The engineer also finds out exactly what the client is looking for so he can choose the proper materials and design. Once the client decides to hire the engineering firm the real fun starts. The preliminary design is full of many important choices.
First is the decision of building materials like concrete, wood, or steel. Depending of the size and application of the building the engineer makes a decision on which material is the best. The next choice is which kind of building system to use. This is usually based on the terrain, location, and magnitude of the project.
The entire design depends greatly on the main load carrying system. For example, while building a bridge you could choose cables, trusses, or arch. Each design works best with a certain material. Cable bridges carry their load through suspension so steel, with its high tension strength, is the best choice. Arch style bridges support the load from underneath so a material with high compression strength such as concrete would be the best choice. Finally any other major decisions such as funding are discussed.
Now the engineer must start to calculate the demand and capacity of the structure and materials. This can be accomplished in the lab as well as with calculations. The key to this project being a success is in one simple relationship, D!" UC. This is stated as demand (load) is less than or equal to the capacity. Let! s say the demand on a concrete column was calculated as 1500 lbs.
The engineer must test and find which size column has the capacity (ability) to handle the demand of 1500 lbs. Next the engineer must design the other components of the structure. At this stage if something doesn! t fit right or if some calculations are wrong the engineer must go through the minor redesign cycle. This simply means that he has to go back to the structures and loads stage and start again. The demand and the capacity must each be recalculated so the design satisfies the relation demand!" U capacity. This includes only minor changes in the design such as the size and arrangement of certain components.
Once all of the design components satisfy D!" UC the engineer does draws and works out the calculations of the design. In doing this the engineer kind of! ^0 struts his stuff! +/- so to speak. The engineer does all kind of fancy drawings and elaborate calculations to show how professional he is. Next the engineer takes the drawings and calculations to the plan checkers.
The plan checkers go through all of the drawings and calculations and try to find if there is anything wrong with the design. If the plan checkers find nothing then it is given their stamp of approval and it goes to the next stage. However, designs do not always get approved the first time. If the plan checkers find something wrong with the type of material used or main load carrying system the entire design goes through the major redesign cycle.
This takes the project back to square one. All of the preliminary design choices are corrected and the engineer has to through structure and loads, and structural analysis process. Then building components are redesigned and sometimes the minor redesign cycle is revisited. Finally when the design is approved the plan checkers a permit is given to the engineer in charge of the construction stage. Here is where the actual design turns into a real functioning structure. Throughout this entire process different engineers can specialize in one field, such as structural analysis or plan checking.
The entire project incorporates many engineers.