Not to put too fine a point on it, but is it improved structural reliability that is being sought or improved accuracy that the reliability levels of today's codes and standards are consistently met? I think the latter. If you want improved structural reliability, this needs to be done via upgrades to the existing codes and standards to maintain the proper balance between public safety and owner costs.
CROSS could provide an indication of of the efficacy of enhanced licensure, e.g., by comparing safety issues before and after implementation of SE licensure, but unfortunately it does not look like CROSS is being widely used - or I have misread the information on the website https://www.cross-safety.org/us.
The point that enhanced licensure makes one aware of what they don't know is the most compelling argument I've heard for SE licensure.
Original Message:
Sent: 03-14-2023 05:38 PM
From: Brian Falconer
Subject: What is a complex structure and why?
SE's must have to have 3 to 4 years of experience in designing threshold structures. PE's can have 3 to 4 years of any engineering experience. Most SE's have a PE and an SE. Discussing the comparative reliability between non-threshold structures and threshold structures is a complex discussion, but definitively I can say that the intent is to make threshold structures more reliable.
Engineers always need to work within their competency, but when you have less directly relevant experience, you know less of what you don't know. When you have more relevant experience, anyone makes better decisions about their own competency. The SE's will be making the decision of if they are competent to design a waste treatment head house, a 60-story office building, or a hospital.
Structural peer review is considered a separate issue from SE Licensure. Some jurisdictions have SE, some jurisdictions have peer review, and some have both. Peer review has been something that has proved to me the value of SE Licensure.
SE Licensure is a state-by-state law; so, any state can legislate it how they want it. I would be curious to hear an idea for periodic review - keeping in mind that we are sometimes designing for 50-to-2500-year events. These events are ultimately going to demonstrate who knew what they were doing, and who did not.
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Brian Falconer P.E., S.E., M.ASCE
Principal
New York NY
Original Message:
Sent: 03-14-2023 02:22 PM
From: Mitchell Winkler
Subject: What is a complex structure and why?
The proposed requirements assume that SEs will have upgraded structural engineering skills and experience relative to PEs. The proposed thresholds could create a situation where nearly similar structures have unequal levels of structural reliability in a hypothetical. What is the thinking here?
SE's will still need to work within their competency area as horizontal structure experience does not necessarily translate to vertical structure experience and vice versa-Ditto for different materials. Unless the SE is differentiated, how will this be any different than the responsibility already placed on PEs that they must work in their competency area?
How has peer review been considered in the deliberations for the proposed requirements? Even the best of us can make mistakes. Here, I think of William LeMessurier and his design of the Citicorp Center structure.
Is any periodic review planned to ensure the new requirements achieve the desired end?
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Mitch Winkler P.E., M.ASCE
Houston, TX
Original Message:
Sent: 03-13-2023 10:25 AM
From: Robert Desmarais
Subject: What is a complex structure and why?
I am looking at the proposed criteria for the stratified PE/SE reqirement. I am curious why an SE would need to design a wast treatement headhouse or wet well, SBR tank, etc. for waste treatment or water treatment. These are Risk 3 structures, yet aren't complex.
Likewise for an educational building. A competent PE is capable of designing a three or four story school building - these aren't complex buildings. To establish a requirement that only SEs could design the building implies a PE isn't competent.
In this NY proposed criteria, I see deligated design isn't included. How then does this square with the concpet? A PE for all intent and purpose could be the steel framing connection designer. The SE in this instance is accepting that a PE is competent for the task when the deligated design is submitted for conformance.
An SE can be authorized to design those threshhold structures but may not have the requisite experience for a spcific design type. It is once again incumbent on the licensed design professional to practice within one's competency. That is no different than having a PE license.
A statement was made that the criteria can inform a building code official which appropriate dsign professional should be designing the structure. This puts an licensure law enforcement obligation on the BCO. Enforcement of the licensure law is not an authorized (by legislation) responsibility of the building code process. In my experience, give a BCO an inch and they will take a mile. I see no reason to extend their perceived jurisdiction.
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Robert R Desmarais Jr, PE
President
rrd pe corp
313 West Liberty Street, Suite 101
Lancaster, PA 17603
Original Message:
Sent: 03-10-2023 01:48 PM
From: Brian Falconer
Subject: What is a complex structure and why?
Though there can be many different types of complex structures, the term is colloquial with regard to SE Licensure. In SE Licensure, we typically talk about a threshold structure as opposed to a complex structure, but the intent is similar.
The goal of SE Licensure is to provide reasonable protection to the public in extreme conditions, and to be effective, a building department official needs to be able to objectively recognize which structures are beyond the threshold and should be designed by an SE. In New York, our proposal with regard to buildings that require an SE is as follows:
- Buildings included in Structural Occupancy Category III or IV.
- Buildings in Occupancy Category II that are greater than 60 feet (18.5m) in height, have a clear span greater than 150 feet (46.3m), are in Seismic Design Category D, or have a total occupant load of more than 1000.
- Buildings that serve as Elementary Schools, Secondary Schools, Hospitals, or Emergency Facilities regardless of their size.
- Alterations where the Change of Occupancy is from an "SE not required" use to an "SE required" use would require an SE regardless of the level of alteration.
- New York State Level I and Level II Alterations without a Change of Occupancy to a higher Risk Category are excluded.
- Non-Structural Components and Delegated Design are excluded.
Clearly, with this definition of the threshold structure, the vast majority of buildings and even the majority of constructed area will not require an SE; however, a hospital, for instance, would.
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Brian Falconer P.E., S.E., M.ASCE
Principal
Severud Associates
New York NY
Original Message:
Sent: 03-09-2023 03:49 PM
From: Mitchell Winkler
Subject: What is a complex structure and why?
In the recent discussion on SE licensure reference was made to complex structures. Given that what may be complex to one engineer may be routine to another what are examples of complexity that cause pause and why? See this link for background discussion.
https://collaborate.asce.org/integratedstructures/discussion/why-se-licensure#bm910d013d-ab5a-4c00-8ba5-2858ae527f59
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Mitch Winkler P.E., M.ASCE
Houston, TX
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