BIM-Does this force the Engineer to become the CAD operator? 2

[kngpenn]

I know that the latest craze right now is Building Information Modeling!

But what does that do to the engineer and/or the CAD operator. Its seems to me that the engineer will be forced to become the CAD guy. If not, then how does the CAD operator know what size beam or column to put where.

Or does that mean that the CAD operator will have to know some fundamentals of engineering.

Any thoughts?

 

[PEinVA]

From my understanding of BIM,

It is similar to the models that engineers build in 3d modeling programs, ETABS, RAM, RISA, etc. Usually engineers do this and set all boundary conditions, fixity, design limits, etc. This can then be imported into a BIM program, such as REVIT. I think some initial work has to be done in order to review the feasibility of a particular design, then from that I would think the initial model would be built.

We had an architect for a bigger firm in our area, come give a short presentation on REVIT, to our office and it was interesting because for them, they don't need to do too much work early on in the project, but for the engineer, 95% of his design needs to be done before the model can be useful to the architect (at least in my opinion) It is definitely going to cause issues with the old school engineers because of the seeming vulnerability of passing information like this so early in the project, which is needed. It seems to change the whole dynamic of the design process.

Having never actually used it to draw, I think the CAD guy can still do all your detailing, etc. but the initial model and layout stuff, would be done primarily by the engineer I think.

That's my opinion, I'm sure we'll see 100 others.

This is a good topic, because it is so relevant to everyone.

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[csd72]

Interesting point, similar concerns have occurred to me. I have not been involved in BIM yet but I feel that for some jobs it would actually be more work than doing it the old way.

 

[kngpenn]

Thus making the engineer the CAD operator in the initial phases of a project.

This could be the very reason that BIM is so hard to swallow with most engineers. Having to provide 95% percent of the design that quickly will be a major obstacle for the old and the new school engineers.

What about the CAD operator? What are they doing while the engineer is crushing the numbers and building the model? Is there any need for a CAD operator once BIM is in place?

 

[PEinVA]

I guess I might have overstated with the 95%. It would probably be closer to a 60-75% set. No, the engineer is not the CAD guy, because the idea of the BIM is to exchange data between programs, as long as we build the model correctly for the design phase, we simply import into REVIT, then we can let the CAD guy take over from there. The initial information needs to come from the engineer though from the model.

The CAD guy is always going to have sections, details to draw and clean up. In theory it is supposed to save some time by skipping a few of the mark-up stages, but it I see the potential for less review going on in a design office when nothing is ever on paper.

The architects love it because it just gives them more fluff to show owners and get wows when something LOOKS cool, but hasn't been reviewed by an engineer, but hey, REVIT let me build it!

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[csd72]

And doing the layout so early leaves no room for checking, rationalisation,e.t.c. before the architect is fixed in their expectations.

One plus I suppose is that the mechanical engineer has no excuse as they know exactly where the beams are.

 

[PEinVA]

haha, star for you csd72.

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[kngpenn]

So if thats your point csd72, then why do you think that BIM is so hyped up?

 

[PEinVA]

I think it is because it will "save" owners time and money, contractors headaches, architects coordination time, and will royally screw the structural engineers!!

Owners have all the $$ so they hype it to make it look like the "wave of the future".

It is going to cause a lot of small companies to go out of business or change their business model.

The one upside is that in 30 years, you'll be able to find a centralized file (BIM file) of a building you would be doing renovations on. Simple enough to review it for modifications then.



RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[SteelPE]

We are in the process of constructing a building that used BIM. The project wasn’t all that bad. It also wasn’t that large of a project. 3 weeks after we were awarded the job the architect asked us for framing plans. I export the current model into AutoCAD, cleaned up the drawings a little (about 15 min per floor) converted them to a pdf and sent them to the architect. I did inform them that they were not complete and that things might change (although they never did). They didn’t seem to mind… after all they had plenty of other things to work on. They did have some problems because they didn’t have a 26K5 in their section database and didn’t know what it was (or what the numbers meant).

The biggest problem I had was nailing the architect down on the details… specifically where interior masonry partitions were so I could locate them on the drawings. They didn’t dimension them on their drawings. They told us to use their computer model to get the information required. This made it impossible to check the drawings by hand.

 

[Lion06]

My firm is starting to get into this now. My understanding is that the geometry of the building (gridlines, floor to floor heights, etc.) will be imported into structural software (such as RAM) from the architectural BIM model. The engineer would then go about framing out the building the same way he always would.

 

[dougantholz]

What SteelPE is describing doesn't seem like BIM. The BIM projects my office has done involve sharing the model with the architects.
IMHO BIM is a tremendous learning curve, that should hopefully force architects to think systemically of the whole building when they start. We have to establish top of steel very early and all edge details have to be well thought of as you are drawing the plans.

 

[druminman]

The way we do it is to have our technicians use architectural backgrounds to produce a structural REVIT model as the arch model is rarely accurately enough and contains too much fluffy stuff. I'll usually give them ballpark sizes for the steel and footings to serve as placeholders.

I then export the structural REVIT model to RISA and add loads and refine member sizes. At this point I'll send our model to the Arch and let them marry the two and adopt our gridlines.

After this I'll finish the design and have the tech update the footing sizes and work on details.

I have never drawn one beam in REVIT.

 

[UcfSE]

I tell my designer what he needs to put where, and he does just that. As far as I'm concerned, I'll get it as right as I can since it has to be done so early on, but if something needs to change, so be it. I can't be asked to have 100% drawings or design before the 35% submittal. All of the engineering is done outside of the BIM environment. We can't get our architects to get 2D cad right; I'm not using their model for engineering.

I'm in an A/E firm with structural, mep and architecture all using the same basic BIM models. Of course, what I said above about me not doing the BIM work itself works because I have a very good designer, imo; not so experienced but he thinks instead of blindly doing. It may not work so well with others.

 

[asixth]

For the original question, the answer is yes, the engineer will become a CAD operator, and I may even say, the CAD technicians are own their way out of the engineering industry.

I for one an embracing the use of revit, and from what I have seen with the CAD technicians using revit to date is that they probably need an good understanding of FE modeling, RC and steel design for revit to become completley compatible with robot. Unless the structure is modeled correctly in revit, it will become absolutley useless when exported to a design package.

I would like to be using revit more than what I can to date because there seems to be a limit with revit and computational speeds.

Personally, I don't like giving a marked-up drawing to a CAD tech and say "change this, change that, remove this, what is that", I would much prefer to get in there and make the changes myself.

 

[RARWOOD]

I'm an older engineer who was still doing hand drawing 10 years ago. Two years ago I taught my self to use Auto-Cad, and since July I have started using Revit to look at an architectural model.


While there are some older engineers who resist change, I have seen the tremendous capability of programs like Revit and RISA-3D and are eager to work with them.

I would agree that one of the major problems with Revit is that it puts a lot of pressure on the engineer to quickly come up with a design early in the project. Mean while as we all know the architect is still designing the project.

My first experience with Revit was on a project where my design was put in to the 3D model by an outside consultant. Later after the architect finished his design the structural details had to be modified. Management was not happy about the additional drafting expenses and could not understand why the orginal structural design needed to be modified.

 

[structuresguy]

We are SMEP firm, and are using Revit for our new projects, but only in structural. our MEP guys are using ABS still. Our architect clients are mostly using CAD, though some are using Revit. We NEVER use their Revit models, as they are way too inaccurate for our use. We start from their plans, and create our own Revit model, which stays our throughout the project. We export floor plans for the architect to review, rather than sending them our full model.

Our process starts out with a review meeting between myself and my designer, to go over the arch plans and identify structural walls, columns, framing system etc... Then the designer is responsible for creating the Revit project, importing arch floor plans, and starting to model walls, concrete columns, etc.. that our known from the plans. Where the architect shows a steel column, he just adds a dummy column to that location to get the model started.

Then he adds floor framing based on the layout (girder orientation, beam spacing, etc) we discussed at the first meeting. Again, he uses dummy beam sizes to get the model going.

I have experimented with exporting from revit into ETABS, but with mixed results. Some things come over ok, but some don't. The end result is that I don't trust the linking nearly enough to actually use it for production work. Certainly not for 2 way data flow, back and forth, from Revit to analysis. The Revit sales team have done an excellent job selling this 2-way data flow capability to company CEO's. It is too bad their programmers didn't do as good a job making sure it works.

So while the designer is working on getting the model going, I am working on my analysis. Depending on the project, I may wait until he has dummy beam framing in place, then export a floor plan to clean up and use as a starting point for import into Etabs. But usually I just start modeling in Etabs (or Staad or Adapt).

I will then give my designer redlined plans with the correct beam/column sizes. If the project is small, he may even wait until this point to start the model. But usually that is not the case. It does not take very long to change the sizes once the model is created. And if he is smart when he lays out the dummy beams, he can change them all at once. For instance, for all infill beams of the same length/spacing, make them one dummy size, different than the girders. Then he just changes it once for all of them.

The designer is then solely responsible for creating the appropriate views, sheets, sections, etc. that are required for construction drawings. of course, I still draw up the noon-standard details by hand, and then he adds them into Revit. We use a mix of live details and "dummy" details. By this I mean, some are cut from the model, and will update if we update the model. And some are just dumb linework.

Since we don't use the link with the analysis software yet, we don't worry too much about the analytical model inside revit. It is very easy for the analytical model to break down, while trying to get your Revit model to look the way you want. By not using it, we save all the time required to maintain a function analytical model.

I know the Revit idealists out there will say we are using the product the way it is intended, and the skeptics will say if we don't use it for analysis, why bother. Well, here are my thoughts on this.

1. It is not faster than CAD for us at this time. Though it is getting closer with every project as we get better.
2. The learning curve is incredibly steep. You need to take courses just to get started. And expect 3-6 months of loss before you gain enough proficiency at it.
3. The 3D modeling can be extremely usefull for us to understand the building so we cna design it correctly, and for us to show problems to the architect.
4. The 3D modeling can be very frustrating when it just won't do what you want. But also can be incredibly cool at times, with how powerful it is in other areas.
5. If you play golf, you know it is a game of frustration and anger management. well, revit is very much the same way. It can leave you angry and frustrated at times. But every now and then, you hit a hole in one and fall in love with it all over again.

 

[Skicat]

I am a structural engineer in training and I also draw and detail my own designs. I can't tell you how excited I am about Revit and I sincerely hope it is here to stay. We are using it in our office and currently one of our CAD techs is operating the program. He does not know how thick the slabs are nor what size to make any of the members, BUT, he never knew that before while using CAD. I can't wait to learn Revit myself and if it can do half of what I think it can do then it should only improve my designs and drawings. I feel like I have a much better understanding of the project because I do all of the drawing and with Revit and its 3D capabilities I have a much clearer understanding of what's going on with the job.

 

[csd72]

kngpenn,

My comment was more about psychology than technology. Client will expect a glossy 3d file to be more accurate than a preliminary sketch, that is just human nature. Managing client expectations is one of the most important, and most difficult, aspects of project management.