Seismic Design in Washington DC

[ThomasH]

Hi all

I have a question that might be very simple.

We are working on a preliminary design of a building in Washington DC. Its a concrete structure, column and slabs, you could call it a stabilizing frame.

1. We have so far used UBC97 and seismic zone 1. Is this what is used in DC or is something else more relevant?

2. The calculations so far indicate tha the seismic (horisontal) load is approximately 10% of the vertical dead load. Does this seen resonable or is it probably to high/low. I only want a educated quess.

I have done seismic analysis i other parts of the world and it seems resonable. I just want to make sure that our approach (UBC and zone 1) is correct for Washington DC.

Regards

Thomas

 

[JAE]

It appears (from the DC website) that BOCA 1996 with 1999 supplements are the current code for the district. I would search out this website below, and contact the necessary persons to validate this code and verify the seismic zone and other requirements (there appears to be a requirement for some kind of Structural Certification document).

http://dcra.dc.gov/services/permits/about.shtm

 

[JAE]

....also -

are you licensed to practice in the District of Columbia?

 

[ThomasH]

Thank you JAE for your help.

As for your second comment you have probably guessed that we are not licensed to practice in the DC. What we are doing now is a very preliminary design, column sizes etc. That means that we need an indication for our results so far. When the project "gets real" there will ofcourse be a licensed enginner involved.

Regards Thomas

 

[JAE]

Thomas: Be careful as some states in the U.S. have non-marketing requirements in their engineering laws as well.

For example, in Nevada, you cannot promote yourself as an engineer to GET HIRED for a project in Nevada prior to being licensed. So if you are serving a client by offering him/her professional engineering advice and preliminary designs, you would be violating Nevada's law, even though you weren't actually completing a design.

I don't know if DC is similar, but you'd better check.

 

[Ingenuity]

JAE,

I have heard of these restrictive-trade-practices that some states have re engineering licenses - it is a ridiculous law in my opinion.

The USA is rather unique in having state-by-state registration - surely it would be easier for all concerned to have a national registration system. It works well in other countries!

 

[JAE]

Well, the term "restrictive trade practices" is rather harsh. I know where you are coming from though.

The USA was originally "put together" as a confederation of independent states that understood the value of merging into one country, yet maintaining their independent rights to regulate their own local citizens. This whole topic isn't really engineering related but rather fascinating if you ever get into it. The relationship between states rights and the federal government has certainly changed over the years, but the primary structure has essentially been left in place for these past 200+ years.

Each state has its own licensing board and the concept of combining it all into one federal agency and one federal engineering license has its attractions. I get very tired of maintaining my 21 licenses and keeping up with the various regulations and continuing education requirements.

But to combine them, as I understand it, would violate the economic commerce rights of each state. So this is a small example of a much larger picture - that of the relationship between a singular federal goverment (and its right to step in and control an economic dimension of a state) and the individual states who still maintain their authority over their citizens.

In fact, the constitution of the US is primarily a document limiting the ability of the federal government to overstep its authority. The 10th amendment specifically limits the feds to ONLY that listed in the constitution.

Too many words above, I see, but I just got on a short roll. sorry.

 

[Focht3]

Good job, JAE. The issue of state-to-state licensing is confusing to those "foreign nationals" with a national licensing structure (i.e. everywhere but the U.S.)


While it may seem that the U.S. licensing structure is ridiculous from a structural engineer's standpoint, it isn't a bad thing from a geotechnical engineer's perspective in much of the geographic U.S.


And on the need to have a P.E. license in responsible charge before doing preliminary design: it's still preliminary engineering design. Odds are you have already committed a violation...