Designing a 2+ Storey House / Building 19

[leakimable]

I recently graduated BS Civil Engineering here in the Philippines -- no work experience, but sadly I do not know how to design a 2 storey house manually.

Yeah the professors in our university thought how to compute beams, columns, footings,etc. individually - using our design codes in our country. But how do you design a whole building in the first place? Isn't there a step by step way of doing it?

For example, analyzing the loads to be carried by the structure . . . then?

I really need your help, I feel like I'm lacking so much knowledge particularly in the field I decide to specialize in.

 

[VAStrEngr]

Unfortunately, I do not know of a step-by-step way of doing it like I think you are looking for but rest-assured that I feel your pain. Don't be overly concerned with what you did/didn't learn in college. If people are honest with themselves, most will tell you that they felt just as unprepared when they started and even a few years after getting into the profession (some "seasoned" engineers will still tell you that you learn new things on each project).

Obviously one general guideline is you start with the top and work down! You need to see the building as a structural system comprised of numerous members but keep in mind that no matter how complex the system seems, it still is comprised of the basic elements of structural engineering...connections, beams, columns, foundations, etc. It sounds like you feel comfortable doing those individual things...you just need experience to see how those things interact together.

The best thing you learned in college is how to learn. It's tough right now that you don't have a job but instead of focusing on being able to sell your abilities, think about how to sell your drive, motivation, and ability to learn/teach yourself. Most companies realize that you don't know jack coming out of school and would rather teach you "their" way of doing things rather than having you come in thinking you know better how to do things than they do.

I'm with you though...I'm young and relatively new to the profession and have this panic often but have had the blessing of a few older engineer mentors to help keep things in perspective.

 

[a2mfk]

I'm sorry to be the guy who does it, but this message board is for practicing structural engineers with a specific problem. It is not a student forum.

But as to your question, don't worry about feeling under-prepared for real world structural engineering, because you are, we all were. School is the first step, it gives you a great theoretical background and lots of the tools you need. But you don't yet know how to use all of those tools, which is normal. Here in the US, it is a mentoring/apprenticeship type program in most states. In most states, you work for a minimum of 4 years as an Engineer Intern (EI) before qualifying to sit for the Professional Engineer (PE) Exam. States vary in their requirements with several now offering a Structural Engineer (SE) Exam, some requiring multiple levels of testing.

Anyway, find a job working with a quality, experienced structural engineer who can teach you the ropes. And you will always be learning, that is why we are all on this message board. I read almost every post to just keep current and learn stuff I never knew... And that is one reason this profession is so interesting and challenging.

 

[leakimable]

@a2mfk
I'm sorry for that.

Here in the Philippines you don't need to have experience to qualify for a Professional exam, and unfortunately(or fortunately) I am a licensed Civil Engineer here in our country - with very little knowledge of the trade. Maybe I just had that urge to learn right away from this forum.

 

[HSIII]

I agree with a2mfk...you will never know everyhting there is to know about structural engineering, because it truly is so vast, and goes along the whole project from concept to design to construction.

Patience is the key. If you have a good senior engineer you're working under, and you aren't afraid to ask questions, you will do just fine. Most senior engineers know where you're at right now...they've been there themselves at one time.

As a final note, one piece of personal advice I can give is don't be afraid to get your hands dirty...literally. Visit construction sites with your senior counterpart. Learn about field testing and what it truly represents. Talk with contractors and subs. You will learn a lot about real-world problems applying design into construction, and also be able to one day become a better engineer because of it.

Keep your head up...you'll get there.

 

[csd72]

leakimable,

Yes you are not the first one in this situation. I got given two houses and was left to figure it out myself - I got completely lost but they expected me to.

Houses are actually the most complex things to design as they have every type of material and often complex load paths. Once you learn how to design a house then it is a really good foundation for larger things.

You only learnt about 10% of what you need to know at college and your learning curve is now going to be very steep. Ask lots of questions, but only once each and keep a notebook with all the things you have learnt.

I will try and give you a process that, though it is aimed at houses, should be applicable to most buildings.

1. Put down that pen/pencil and just have a look through the drawings for a half hour or so. Do you understand them? do they have enough information? How is the structure going to work for gravity and lateral loads (wind/earthquake). now pick that pencil up and write down these questions to ask the architect/senior engineer leaving space to write the answers. At this stage a comprehensive list of intelligent questions will make a good impression and avoid having to redo misunderstandings.

2. Now first page will be a summary of loads, note live loads, calculate basic wind loads and any earthquake loads. Also note any areas that may have excessive dead loads - this may add to your list of questions (e.g tile thicknesses). Double check all your parameters and calculated loads before moving on to the next step.

3. Now design the roof structure, if it is all similar loads and spans use one member size for the whole roof, otherwise use a maximum of 3 sizes for each type of member. Make sure that your dead loads allow for the weight of any roof coverings or cielings and and srvices. Clearly note reactions as these will be used for walls and then foundations.

4. repeat step 3 for floor members.

5. now look at the walls for vertical and horizontal loads, design studs and cladding /bracing.

6. now look at connections e.g tie down straps e.t.c and sketch the critical details.

7. transfer loads down to ground and size foundations.

Focus on simplicity rather than pure material economy as this normally leads to the cheapest and least problematic build.

Keep timber sizes, grades and species to those that are readily available in your area. If you are going to do a lot of these then it is really worthwhile knowing what the cheapest structural timber is available so you can use this as much as possible.

Find out what typical local practice is and follow it unless there is a good reason to do otherwise.

Make sure that you get to see this building being built as nothing compares to the reality.

i am sure that I have answered a similar thread before in more detail, so use the google at the top of the page to search for previous threads.

 

[msquared48]

csd has a pretty good summary there.

A couple of extra points though:

1. Try to avoid transfer beams if possible - take out the vertical loads of any particular story at the columns of that story, otherwise the beams below will have to be larger. i.e., try to stack your vertical loads.

2. Arrange the shear walls similarly, stacking them where possible. And use enough walls to minimize the size and complexity of any shear walls.

3. If available, use a roof truss package over stick framing as it will be cheaper and the olads will be generally transferred to the outside walls and columns rather than inside columns and walls.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[hokie66]

leakimable,
Welcome to the site. As you have graduated, you are perfectly entitled to contribute.

All the advice you have been given above is good, but some perhaps not applicable to how houses are built in the Philippines. There are a lot of different housing methods employed around the world. Perhaps your first step is to study how your local building industry goes about the process. Find out how the footings, floors, walls, and roofs are typically structured and what materials are used, then come back to us with more specific questions.

 

[csd72]

http://www.philippines.hvu.nl/housing1.htm

http://philippines-construction.blogspot.com/2008/12/philippine-house-design.html

http://www.bluecirclebuilders.com/

Architecture is very different, but the construction is not worlds away.

 

[a2mfk]

I feel jerky for my original post. What I meant is from my short time on this list, it is more geared towards professionals with specific questions. But by all means, join in and learn. That is what I am here for more than posting questions of my own.

Having traveled and witnessed construction in other countries such as Thailand and Peru (not the Philippines though), the starkest differences to me are economic considerations, lack of building codes or enforcement, availability of materials and the usage of local resources rather than those that are imported, and the availability of cheap but often unskilled labor. And even in the US, a very large difference in construction between metropolitan areas and those in rural areas.

For example, modern skyscrapers dot the downtown skyline of Bangkok, but go an hour in the country and you see bamboo stilt houses. Very similar in Peru with Lima vs Juliaca, where the biggest local industry was homemade mud bricks. I imagine some of the same may be the case in the Philippines.

My point being that as a structural engineer, you are likely going to find employment in Manila or a big city where there is a demand for those services. I am guessing that will entail lots of masonry and reinforced concrete, and some steel design (I'm opining). Differences in labor vs material costs may factor largely into some of your design decisions. So understanding your local market and codes, and learning common construction practices in your area will benefit you greatly, as it does anywhere.

I have seen reinforced concrete and masonry houses in poorer Caribbean islands because that is the material of choice because it is mostly locally sourced, while in the US we build many houses out of wood... Which is better?

Keeping that in mind when soliciting advice from this board, such as the practical considerations in your locality. What we say may work great in Chicago or Vancouver, but maybe that would require a piece of equipment or style of construction that is not practical where you live. I read articles about construction in Europe and Japan and sometimes am amazed by the different techniques and materials versus North America.

But the great thing about structural engineering is on a basic level concrete is concrete, steel is steel, and math and material mechanics are universal.

Cheers and best of luck on your new career!

 

[SlideRuleEra]

leakimable - The 434-page book "Residential Structural Design Guide - 2000 Edition" covers the design of house, including those with more than on story. It is a free .pdf download here:

http://www.pathnet.org/sp.asp?id=1442

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[structech08]

Leakimable,

Being a newly registered civil engineer will not qualify you immediately as structural engineer. Note well that, in the Philippines, there is an association called ASEP (Association of the Structural Engineers in the Phlippines) who are the practicing structural engineers under a registration of civil engineer. Due to wide range of scope of civil engineering practices, PRC (Professional Regulation Commission thru PICE) categorize civil engineering practices into five specialization to fit your interest, visit,

http://www.pice.org.ph.

One is structural engineering as the speciality. Others are: geotechnical, construction management, transportation and water works and hydrology. Be an active member of PICE or ASEP to meet practicing structural engineers in the Philipines.

I understand your interest in this field. Do not be in a hurry, it takes long years of patience, continuous education and diversified experience to be in this field.

If you have time and resources, get a masteral education in structural engineering to augment your BSCE education. But most, try to gain experience in this field by being employed in structural engineering consultancy. Know also the civil engineering responsibilities. If you are the engineer-of-record, you are responsible for fifteen (15) years if you are the EOR. It is a serious responsibility to yourself and countrymen.

Regards,
structech08