# Ask the Structural Engineer! **URL:** \ **Category:** In My Humble Opinion\ **Created:** [May 20, 2003, 7:34pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365 "2003-05-20T19:34:53Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![OxyMoron](https://avatars.discourse-cdn.com/v4/letter/o/e9a140/32.png) [@OxyMoron](https://boards.straightdope.com/u/OxyMoron)\ **Post date:** [February 11, 2005, 7:01pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/101 "2005-02-11T19:01:07Z")
Augh! Quick, a wooden stake!!! 2003 thread is…_alive_! ---
**Author:** ![GaryBranson](https://avatars.discourse-cdn.com/v4/letter/g/ed8c4c/32.png) [@GaryBranson](https://boards.straightdope.com/u/GaryBranson)\ **Post date:** [August 18, 2011, 7:11pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/102 "2011-08-18T19:11:36Z")
Hi all. I am a solar installer and have come across a new technology that I want to use to create shade structures for parking lots. This tech is a dual-axis tracking array designed to be installed on the ground and have only a foot or two of ground clearance for its tracking path. It catches the wind like a sail, although when the wind blows over 15 mph or so, it goes into face-down stow mode. I would like to raise up the pedestals/piers that support it by a good 12 feet to make it viable to install in a parking lot with nobody crashing into the things. Normally, they require a 16-foot-deep hole in which to anchor the pier. My question is how much deeper a hole or thicker the pier would I need to raise this equipment by 12 feet? And what sort of equipment is able to dig down that far without completely stripping a paved parking lot? ---
**Author:** ![Daylate](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@Daylate](https://boards.straightdope.com/u/Daylate)\ **Post date:** [August 18, 2011, 7:31pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/103 "2011-08-18T19:31:56Z")
> [@](#): > > Does your hatred of architects burn with the fire of a thousand suns? Or does it merely smoulder like BBQ charcoal, only flaring up at the approach of architectural flesh? In my day we always said that an architect was someone who started out in engineering school but flunked Indeterminate Structures. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [August 18, 2011, 11:52pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/104 "2011-08-18T23:52:12Z")
What is a typical day like? How much time do you spend running simulations (hey, VR is good for something!), building scale models and hitting them with hammers (or a controlled force…), attending meetings, translating client requirement documents into proposed diagrams, playing minesweeper, etc.? What is the professional regulatory system like? Do you have standardized board exams or certification processes that you have to go through to call yourself a “Structural Engineer”, or is it just a matter of convincing someone that you’re good enough to hire? There is no such thing here as a “Board Certified Software Developer”, and we are afraid of such a thing because the industry changes so quickly that any certification exam or practical curriculum (that is, the applied stuff, beyond fundamental, theoretical Computer Science) is going to be obsolete by the time the State Legislature approves its use. What are your customer relationships? Do you work for a faceless consulting company that sends you to client after client, or are you the “staff structural engineer” who is responsible for the new construction being done in-house (no pun intended). Are you independent, taking contracts here and there helping out one construction firm one day, the local government the next, etc… ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [August 19, 2011, 12:27am UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/105 "2011-08-19T00:27:58Z")
Do you want to murder Frank Gehry? Because I sure do, and I’m not even an engineer. ---
**Author:** ![Tabby\_Cat](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Tabby\_Cat](https://boards.straightdope.com/u/Tabby_Cat)\ **Post date:** [August 19, 2011, 2:55am UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/106 "2011-08-19T02:55:33Z")
Guys, we’re going to need a 2x4 to kill this one. ---
**Author:** ![The\_Flying\_Dutchman](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@The\_Flying\_Dutchman](https://boards.straightdope.com/u/The_Flying_Dutchman)\ **Post date:** [August 19, 2011, 4:52am UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/107 "2011-08-19T04:52:17Z")
I used to manage construction back in the seventies and eighties and sometimes we would submit a simple alternative design proposal for approval. It was always frustrating to have to get an approval from an engineer, never mind the wait. And then there was the [Kansas City Hyatt Regency walkway collapse in 1981](http://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse) Such a minor change. Such a major mistake. What do you think of the spate of outdoor stage failures we’ve been having lately. Not enough attention to wind load ? ---
**Author:** ![The\_Flying\_Dutchman](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@The\_Flying\_Dutchman](https://boards.straightdope.com/u/The_Flying_Dutchman)\ **Post date:** [August 19, 2011, 4:58am UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/108 "2011-08-19T04:58:48Z")
Fuck !!! ---
**Author:** ![Dereknocue67](https://avatars.discourse-cdn.com/v4/letter/d/6de8d8/32.png) [@Dereknocue67](https://boards.straightdope.com/u/Dereknocue67)\ **Post date:** [August 19, 2011, 8:25am UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/109 "2011-08-19T08:25:48Z")
I have a question involving cracked brick veneer on exterior walls. Specifically, a fairly common crack radiating away from an opening (door, window) as it stair-steps up a brick wall with the crack evident at the mortar joints only. If you could rule out settlement as a contributing cause, what in your opinion, is usually the culprit for this type of crack? ---
**Author:** ![Littlehomebuilder](https://avatars.discourse-cdn.com/v4/letter/l/c77e96/32.png) [@Littlehomebuilder](https://boards.straightdope.com/u/Littlehomebuilder)\ **Post date:** [April 6, 2012, 4:43am UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/110 "2012-04-06T04:43:18Z")
I am designing a small home (1250 sf)in North Texas, and am considering foundations. With the black clay all around, would it be prudent to use short bored piles, or is there a better option. Any advise would help thanks. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 6, 2012, 4:50am UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/111 "2012-04-06T04:50:22Z")
> [@OxyMoron](#): > > Augh! Quick, a wooden stake!!! 2003 thread is…_alive_! > [@Tabby\_Cat](#): > > Guys, we’re going to need a 2x4 to kill this one. zombie or no maybe an iron bar. ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [April 6, 2012, 5:31am UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/112 "2012-04-06T05:31:37Z")
Zombie or not, **culture** should have the decency to monitor this thread. He is a professional, after all. Kidding aside, I suggest that\*\* Littlehomebuilder \*\*look at what the local custom is in his area. Tale a look at some of the older buildings in the area and see what they used. Local builders will have opinions too. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 6, 2012, 12:22pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/113 "2012-04-06T12:22:59Z")
> [@Littlehomebuilder](#): > > I am designing a small home (1250 sf)in North Texas, and am considering foundations. With the black clay all around, would it be prudent to use short bored piles, or is there a better option. Any advise would help thanks. even though basements might not be common in your area, you should make an in ground storm shelter. ---
**Author:** ![scottg1](https://avatars.discourse-cdn.com/v4/letter/s/c57346/32.png) [@scottg1](https://boards.straightdope.com/u/scottg1)\ **Post date:** [April 10, 2012, 7:28pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/114 "2012-04-10T19:28:54Z")
> [@culture](#): > > Who the heck would want to ask me a question? However, I would still be glad to answer any. > > Structural Engineering, the bold, sexy profession! single-story ranch 24’ wide. 3/12 pitch. want to remove 13’ of load-bearing wall between kitchen and livingroom. beam size? ---
**Author:** ![Spectre\_of\_Pithecanthropus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spectre_of_pithecanthropus/32/12343_2.png) [@Spectre\_of\_Pithecanthropus](https://boards.straightdope.com/u/Spectre_of_Pithecanthropus)\ **Post date:** [April 13, 2012, 7:47pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/115 "2012-04-13T19:47:14Z")
> [@culture](#): > > We have a saying: “it’s not architect, it’s damn architect.” > > When I explain what I do to some people, they say, “ohh … so you are an architect.” No, architects draw what the building is to look like. The structural engineer actually draws the plans used by the construction company to building the building. As a layman this makes sense to me; but I’m curious about architects then. Besides drawing 2D representations of the proposed building, I suppose they are also the ones who build the small scale mock-ups, presumably useful in selling the plan to the customer. But isn’t there also a technical component to their education and training? After all, they need five or six years of postsecondary education to get the degree. As for structural engineering, I have a specific question. If I put a mug of coffee directly on the bed, it’s rather unstable and can easily be tipped over, but with a plate or large flat book underneath, it becomes much more stable. Is there an analogy to this in the way building foundations are designed? For example, in soft soil? ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [April 13, 2012, 9:48pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/116 "2012-04-13T21:48:09Z")
> [@Spectre\_of\_Pithecanthropus](#): > > If I put a mug of coffee directly on the bed, it’s rather unstable and can easily be tipped over, but with a plate or large flat book underneath, it becomes much more stable. Is there an analogy to this in the way building foundations are designed? For example, in soft soil? As I understand it, you bore a hole through the mattress right down to the floor. Then you slip a pipe the same diameter as the base of your mug into the hole. Set the mug on the top end of the pipe. Nice and stable. ---
**Author:** ![Hakuna\_Matata](https://avatars.discourse-cdn.com/v4/letter/h/a88e4f/32.png) [@Hakuna\_Matata](https://boards.straightdope.com/u/Hakuna_Matata)\ **Post date:** [April 13, 2012, 10:21pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/117 "2012-04-13T22:21:34Z")
> [@Spectre\_of\_Pithecanthropus](#): > > As a layman this makes sense to me; but I’m curious about architects then. Besides drawing 2D representations of the proposed building, I suppose they are also the ones who build the small scale mock-ups, presumably useful in selling the plan to the customer. But isn’t there also a technical component to their education and training? After all, they need five or six years of postsecondary education to get the degree. I will take a shot at this – even if this is a zombie! Using a human body as a metaphor–the structural engineer is only responsible for the actual physical structure of the building, the bones if you will. That work is typically hidden by my work, the skin and the guts. The engineering drawings will show the sizes of the beams, etc, but the physical location of those elements typically falls in the Architects domain as he is responsible for coordination of all the consultants. In other words the structural engineer may call for a 8" PT concrete slab but where that slab edge is would be my responsiblity, as I know where that slab needs to be relative to the curtainwall for example. The architect is responsible for the meeting the building code, making sure that ‘you’ the public gets safely out of the building in case of a fire or some other calamity. It is my job to ensure the health, safety and welfare of the general public. As such I employ structural engineers, and electrical, plumbing, mechanical and a few other specialists to aid me in that endeavor. But they typically work directly for me, the client hires me and I hire a team of consultants to assist me in the work. If there is an issue on the project the client comes to me, as does the general contractor. I would then involve the appropriate consultant to assist me in solving the issue. I know Architects are notorious for being pains in the asses, and I am sure I have had my share of people mad at me too. But I have larger responsibility on the project and I must take into account ALL of the components. A structural engineer is typically only interested in his structure, but in a building we have to fit the plumbing in, the mechanical, the electrical, interiors, landscape, cabinets, etc. It is easy to complain if you are only responsible for one entity of the building but I can’t let one entity control the design solutions. However in my 30 years experience I rarely have found any issues working with structural engineers to be honest. They have their job to do and I have mine, and my experience is that the vast majority of them are excellent at their job. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [April 15, 2012, 2:36pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/118 "2012-04-15T14:36:41Z")
> [@Spectre\_of\_Pithecanthropus](#): > > As for structural engineering, I have a specific question. If I put a mug of coffee directly on the bed, it’s rather unstable and can easily be tipped over, but with a plate or large flat book underneath, it becomes much more stable. Is there an analogy to this in the way building foundations are designed? For example, in soft soil? It’s all about forces and moment arms. A “moment” is the product of a force on an object and the distance that force is applied (moment arm) from the point of rotation. For example, if you are hanging from a slender, uniform beam that is sticking out of the wall of a building, you are more likely to break it off the further from the wall you hang from it. That is because as you move further away from the wall, your moment increases: | |------- | | The same pricipal applies to your coffee mug or a building foundation. The required moment to tip the coffee mug a function of the weight of the mug x the distance of the center of gravity ! to the point of rotation (x) at the edge of the mug. When you put a plate on the bottom of the mug, ot point of rotation is now further from the center of gravity and the moment increases. It now requires more force to tip it over. a) x|_!_| b) x\_\_|_!_|\_\_ ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [April 15, 2012, 3:40pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/119 "2012-04-15T15:40:24Z")
Clearly, this thread was designed to last! ---
**Author:** ![gfinner](https://avatars.discourse-cdn.com/v4/letter/g/d78d45/32.png) [@gfinner](https://boards.straightdope.com/u/gfinner)\ **Post date:** [July 3, 2012, 7:32pm UTC](https://boards.straightdope.com/t/ask-the-structural-engineer/176365/120 "2012-07-03T19:32:09Z")
I have a porch 9x5 at the front right side of my house. Directly above it is a bedroom. The joists of the bedroom cantilever out 5 feet over the exterior wall. The joists are 2x10s spaced 16 oc. This house was built in the 80s. Just wondering if that is structurally sound. In Canada so we get snow. [Previous page](https://boards.straightdope.com/t/ask-the-structural-engineer/176365.md?page=5) [Next page](https://boards.straightdope.com/t/ask-the-structural-engineer/176365.md?page=7)