Structural Engineering jobs are responsible roles and needs careful learning. To become an expert in structural engineering, one need to have essential basic understanding of structures and adequate experience working or learning under a practicing consultant. Before starting own structural consulting, it is essential that one get involved in structural engineering jobs under established consultants.
Here are some of the essential steps you should learn and experience to master structures. These steps can guide you to plan your structural design learning.
Knowing the Role of a structural engineer
Many Civil engineering students and engineers really don’t exactly appreciate what the role of a structural engineer is. It is not limited to preparing a computer aided analysis model in ETABS or STAAD Pro. It is much more than this. Knowing the role of a structural engineer is really important so that you can plan and pace your learning well.
The main Role of a Structural Engineer is listed below.
Ensure Strength
Most young and entry level civil engineer thinks that the role of a structural engineer is limited to the strength aspect. That is to issue drawings that shows the size of columns and beams. Deciding depth and size of footing and thickness of slab. Also, the reinforcement needed in these structural members. When ensuring strength of members is an important structural aspect, there are many more important structural things that one need to ensure.
I have put this as a structural design free course here.
Ensure Stability
If you have been following my structural blogs and videos and posts for a while, you would have seen me emphasizing on stability of structures many times. It’s a key aspect which most young structural engineer ignores. Most recent failures of building structures have a stability reason as the trigger of failure. Instability can also create disproportionate collapses and irreparable damages. The free structural design course which I mentioned in the previous section includes all aspects of stability. Many practical aspects of stability of buildings are covered in this. If you want an additional blog on stability of structures, please see this blog.
Ensure serviceability
Serviceability means useability. The building should perform the intended functions for the intended life time. For this, we need to ensure the building is durable, the deflection of members is within limits and also that the crack widths of the members are with in permissible limits.
Durability of structural members are very important. Though it may not create an immediate failure of structural members, lack of durability can cause long term structural problems. Proper cover to reinforcement and adequate mix of concrete are the 2 things needed to ensure durability. Many engineers think that site engineers ensure this. But the design engineer should specify the cover and mix of concrete and the site engineer ensure the specified is applied at site. Many thinks that mix of concrete is related to only strength. In fact, it is related to durability as well.
I will only talk about durability in this blog. Other things i.e.; controlling deflections and crack widths are more important and are in fact mentioned in the free structural design course that I mentioned in the previous section. Please ensure you do the course to understand these important structural aspects on serviceability of buildings.
Ensure the design is buildable
Many young engineers don’t focus on this aspect of buildability. Their energy is spent in mastering software tools like ETABS and Revit. This is useful only if the end result is buildable. It is very important that one know the buildability challenges. You need to look at the building site interfaces. Things like if there is an existing building nearby and if the foundations are protruding to the site and so on. There can be hundreds of things on this point based on the project conditions.
Ensure information is received, provided and executed
All good structural engineers have to be good listeners. Many times, client don’t appreciate the sensitivity of structural information. They don’t know what a structural engineer need. So, we have to be good listeners to pick up each client brief, probe on it and gather sufficient information to ensure the buildings are safe and economic at the same time.
Knowing to scheme a building
Scheme of a building is an important aspect. A civil engineer should be able to decide the preliminary structural scheme at least. You should be able to understand the architectural requirement and fairly co-ordinate the structural requirement. Generally, one should know these below mentioned points about scheme development. If you are not a master in these, focus in learning these.
Good configuration
A structural scheme generally shall perform well during earth quakes as well and hence should be robust and take care of irregularities. A regular building is better. However current functional and architectural requirement can be challenging and you may have irregular shapes and forms for the building. You should have a good structural understanding to deal with irregular shapes and make the scheme perform well.
Deciding Column Position and Orientation
One need to be able to fairly judge the column position keeping in mind both architectural and structural requirement. Same way, the orientation of the columns is very important. It is not easy for me to explain all these in a blog and therefore, I have provided a webinar link in this blog. Please read the blog fully and you will find it.
Deciding Beam Positions
Deciding beam positions and its depth is also a part of the scheme development. You need to be able to judge when why and where the beams are needed. Many young engineers have doubts like if a plinth beam is needed, if a grade slab is needed in a building etc.
Generally, beams are needed for 3 reasons.
To break the slabs in to manageable thicknesses.
To support a wall above the slab
To act as a tie for the columns.
Your attempt should be to meet all these needs with minimum numbers. All these can be done only with adequate experience working or learning from a structural mentor.
Deciding Shear wall Positions
You need to be able to decide if a particular project needs a shear wall. If you need it, where it should be provided. Around the lift or somewhere else. The decision should be based on careful seismic and wind analysis. You should ensure that the building don’t experience torsion. All these needs careful learning under a structural mentor or a consultant. Many young engineers even don’t appreciate what a shear wall is. Many get carried away with definitions based on aspect ratios or the Length to thickness ratios. You can check this blog here to learn what a shear wall is
Load calculations
You need to be able to calculate all loads correctly. Not more, not less but accurately. Refining loads is one of the main aspects to achieve economy. You should be able to calculate the loads from water tank, staircases and some times from the roof trusses and so on. You should have all understanding of seismic loading and wind loading. Some times young engineers may be confused on lift loads – if it is acting at the lift pit level or at the machine room level and so on. You should have good ability to read architectural drawings and MEP drawings and understand their requirements with respect to loads.
You need to ask the right questions at the right time. If some says I want to build a reading room - Is it just a reading room or a large library. Will there be any storage or even a statue there? You should be able to judge. Experience matters. So do real projects.
Essential Basics
It is hard to state what are the essential basics needed. Basically, you should be able to appreciate the behaviour of structures. You also need to know the concepts. See if you are able to answer some of the questions below. You should be in a position to answer these.
Will you fix or pin the column base?
When will you model a slab as a shell?
How do you identify if a wall is a shear wall? Many answer this based on the length to thickness ratio. That is not really true.
There are many more. I just mentioned a few for your understanding so that you focus on similar structural things.
Analysis including wind and seismic
Understanding and appreciating the behaviour of a structure is analysis. You will have to understand the response of the building to the loads. This can be to gravity loads or wind or seismic. You will need to appreciate deflections and drifts and limit it to permissible values. If the deflections are large, you also need to decide if you need shear walls and the position of these. You should be in a position to decide the geometry of the building. Say if a L shaped building is fine or you need to split them in to 2 regular rectangular buildings. You need to decide when you will need to do a dynamic analysis. There are far more important things you need to know.
The only way is to work on real projects and learn from a mentor who can help you out. If you get a job, you are lucky to be mentored by some body on job. However, be sure you join a company who are good at design, and do things properly without compromises. If not, you will end up doing wrong things. To avoid these, learn as much as you can in the period when you hunt for work. Join a course or ask seniors if they can help. The key is doing real projects and understanding basics.
Relevant Structural Software
By now you would have known that a mere software learning is not adequate to be an independent Engineer. However, software is a must now for accurate and quick computation. Most training institutes just focus on basics of software. It is very important to know how to transfer our design considerations in to software. As an example, if you talk about ETABS, you need to know when to use slabs as membrane and when it should be shell thin. How you use software matters! There are many parameters that will need inputs in any software. Stiffness modifications, Torsion release, Effective length of columns, Braced or unbraced column inputs are all some examples. If you don’t know what these means, you need to revisit your basics. Which structural software to learn? Most institutes package a few software and offer you reductions. Many a time it is a trap showing numbers. Software like 3D Max is not at all useful for students aspiring to be structural or civil engineers. Generally, you will need ETABS for analysis & Design of levelled building structures. I find it superior than any other software. Staad Pro is another popular in this area. However, this is more of a general-purpose software for buildings I suggest ETABS over STAAD. SAFE or ETABS itself can be used for analysis and design of foundation systems like raft. Both are very similar in results and both are from same company CSI. BIM is an emerging technology. Most companies have already migrated away from conventional CAD platforms and has embraced BIM. REVIT is the most popular building related BIM. In this REVIT STRUCTURES is what an aspiring structural engineer should learn though most of the basics are same. Until and unless you know to produce RCC details using REVIT, it is not complete. Most institutes teach just the architecture part. Therefore, it is very important to learn these from consultants who has used these.
Design including hand calculations and manual designs
Why do you need to do this? There are various software and spread sheets available in the market using which one can design most members very fast. However, a thorough basics and manual design is desirable so that you learn the design steps. Tomorrow you can even develop such sheets and also get an opportunity to work in companies like CSI which is the company that owns the software ETABS. Also, manual design will validate your sheets for accuracy. Your basics are going to develop in the process as well. So don’t bypass this step for easy solutions. You need to be good at basics. Learn. If you need, take help from a mentor or an online course. Most of the beam and slab design is very straight forward. However, when it comes to column designs, most text books do not explain calculation of effective lengths. This is very much needed for computation of slenderness and then deciding the slenderness moment. Effective length is not floor to floor height. One need to establish this by calculating sway index.
Validation & Interpreting key analysis results
If you are having sound understanding of basic principles and manual calculation ability then validation comes natural to you. You should be adopting 2 kinds of validation in design. One is process related. This ensures a checking process is in place to capture mistakes in modelling, measurement etc. This also ensures the design calculations and drawings are checked and validated.
Another validation is about ensuring the structural behaviour matches with the expected checks. One example is a quick check of the vertical load take down by an area method check. One also need to check and ensure the behaviour of beams are all as expected.
Co-ordination with other stakeholders
I have already highlighted the importance of communication. Co-ordination between different disciplines is very important for the wellbeing of the project.
Lack of co-ordination will affect the scheme to loading and this result in poor structural design. An example is the cutout positions in slabs and beams. If this is not well coordinated the cutouts may clash with beam positions. Some times this may result in core cutting in beams which is not structurally feasible.
Same way, co-ordination with Architects and clients are also very important to ensure evey structural requirements are met correctly.
Structural Detailing
Structural detailing is one of the most important steps and a good structural engineer needs to be a master in detailing. Your structural design is conveyed to site by means of structural drawings. You need to detail by hand sketches to master structural detailing. That is perhaps the only way. You need to spend time in sketching and getting it corrected by a mentor. You can refer SP-34 which is a hand book for RC detailing and visit site and understand the detailing.
How do you master this? However good you are in structural design jobs, that does not matter unless you convey your design in the right way to site engineers who build or execute the structural design. Also note that our structure has a very large amount of re-distribution ability. So, if you detail in the right way, lot of bridging helps us to take care of a potential design mistakes. There have been instances of failure just because of bad detailing. Also, there are many opportunities emerging in this structural detailing sector and Bar bending schedule preparations. Revit is an excellent tool to start your BIM and structural detailing.
Ensuring buildability
I have already mentioned the importance of the designs being buildable in a previous section. There is no point if your designs are not buildable. So utmost care shall be given to ensure your designs are buildable at site. The site interfaces should be taken care.
If you are choosing precast as a structural system, you should ensure the site is spacious to allow for the movement of materials and erection of the precast.
Same way choice of materials and methods also need to match with the local availability.
Summary
There are many more steps one need to master to be successful in structural design. Some of the key steps are mentioned in this blog. Some of the steps are long term and it will come as one starts practicing structures. Many things are not writable in a blog. I have tried to clarify some points in a webinar. The link to the webinar is provided at the end of this summary.
In case you are wanting to set up your own, some more additional points you need to learn, practice and master.
Adhering to building rules, Essential company and Registrations needed to practice structures, Essential memberships, Ways to win and maintain clients, Key communications are all part of the roadmap for becoming successful structural engineers. I will write a separate blog some time on these topics.
I suggest you attend this webinar to know the key points more clearly.
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