Talk:Proposed features/building:soft storey

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Definition

Presently "a type of construction where any one floor is significantly more flexible (less stiff) than those above and below it". But it is not a single construction, it is "any building where one or more floors is significantly more flexible (less stiff) than those above and below it"? I think that is better. Warin61 (talk) 09:12, 24 January 2019 (UTC)

That too is wrong, the values of yes/no don't match the description! Umm "Building stiffness to IBC" and then the values should be pass/fail/reinforced ??? Something like that. At the moment a 'yes' value says what? That the building is flexible, that is what the definition reads like with the answer 'yes'? Warin61 (talk) 09:27, 24 January 2019 (UTC)
Let's not confuse building stiffness with just one level of a construction being more flexible than others. I have not invented the definition, it's the one used by FEMA and Applied Tech Council, seen also in many engineering research papers on building structures and resistance to earthquakes. It's more general purpose and applicable to any part of the world, to wood-frame buildings, concrete, steel, mixed. It's more compact and more general than the one used in Wikipedia (which seems to be very San Francisco/California-centric --see notes 1 and 2 in https://en.wikipedia.org/wiki/Soft_story_building).
As for the values, Fail/pass imply that there is a (standardized?) test and this is not the case. Yes means that one storey of the building is more flexible than others. Reinforced means that there is evidence that the building has been brought up to code. The tag needs to be applied by people skilled in recognizing such buildings (it's clarified in the proposal). Think of this tag as the optional tags for power converter: only experts will fill those in. --Smaffulli (talk) 11:46, 24 January 2019 (UTC)
The definition is a type of construction I would think there are many 'types of construction' and each of them can have one of more floors more flexible than the others. The 'type of construction' needs to be drooped. Warin61 (talk) 22:06, 24 January 2019 (UTC)
I fail to see the logic in what you wrote. Can you please try to rephrase? Maybe write a definition that you would find acceptable. --Smaffulli (talk) 23:38, 24 January 2019 (UTC)
Types of building construction are;
* Concrete Frame Construction
* Steel frame Structures
* light gauge steel structures
* Wood Framed Construction
* load bearing masonry wall construction
* large panel Concrete Construction
* precast concrete construction
* earthen architecture
* bamboo construction
* tensile structures
A buildings flexibility is not a result of the type of construction but the design and build. Warin61 (talk) 01:35, 25 January 2019 (UTC)
Thanks for that list... All of those can be classified as *Soft Storey*. It's still not clear to me what you're arguing in favor of. Can you please try to write down an alternative definition you'd find acceptable? --Smaffulli (talk) 09:31, 25 January 2019 (UTC)
Does this assessment apply to more than buildings? If only buildings than that needs to be in the definition, e.g "Buildings where any one floor is significantly more flexible (less stiff) than those above and below it" If it applies any structure then "Buildings where any one level is significantly more flexible (less stiff) than those above and below it" Warin61 (talk) 22:06, 24 January 2019 (UTC)
Only buildings (in the OSM definition of Buildings, otherwise the key wouldn't be 'building:key'. Are you arguing the use of the term floor vs levels? In civil engineering, a floor is the surface you walk on. --Smaffulli (talk) 23:38, 24 January 2019 (UTC)
'Floor' is used in the present definition. I am trying to point out that 'type of construction' is wrong here. Replacing 'type of construction' with 'building' and what is lost? Warin61 (talk) 01:40, 25 January 2019 (UTC)
Thanks for the explanation. I now understand what you're saying. I find 'type of construction' better than 'building' in the definition, since they're interchangeable. Opinions :) Since I believe you feel strongly about this, I changed the definition.

Values

At present the explanation of the values yes/reinforced/no need to be searched for. These things should be the first things stated in tagging, in a very clear way. The method of evaluation is separate from the tagging values themselves and should be delt with as a another issue. Warin61 (talk) 22:06, 24 January (UTC)

I'm failing to understand what you propose here. Can you provide an alternative of how you'd describe the values? --Smaffulli (talk) 23:38, 24 January 2019 (UTC)
Directly under the subtitle 'Tagging' state how the tag is to be use e.g. "On a building that has been assessed as having a 'soft storey' add the tag building:soft_storey=yes. If the building building that has been assessed as having no 'soft storey' add the tag building:soft_storey=no. " etcetera. This should be the first statement, keep it simple. Explain how or reference documents for how the assessment is made could come after it. But first tell them what the values mean. That is what the 'Tagging' section is about - what do the key:values mean. Warin61 (talk) 01:51, 25 January 2019 (UTC)
The stated goal here is related to indicating seismic hazard relating to buildings. As it stands, it is incomplete - soft story is only one of a set of building characteristics that can be visually identified. All of these contribute to the hazard. In Rapid Visual Screening of Buildings for Potential Seismic Hazards look at the illustrations contained in Table B-4 Vertical Irregularity Reference Guide ( page FEMA P-154 Appendix B: Data Collection Forms and Reference Guides B-15 ). It appears alongside other equally significant characteristics like Sloping Site, Unbraced Cripple Wall, Out-of-Plane Setback, In-plane Setback, Short Column/Pier, and Split Levels. Also the characteristics in Table B-5 Plan Irregularity Reference Guide can be easily identified from aerial photographs. Tables B-3, B-4, B-5 and somewhat B-6 are very understandable identifiable by even untrained people.
If you have to simplify and flatten the FEMA schema, building:soft_storey=yes/reinforced/no might look like
building:seismic_soft_storey=yes/no/inconclusive/score ( inconclusive means I looked, but couldn't make a definitive conclusion, score allows future refinement )
building:seismic_sloping_site=yes/no/inconclusive/score
building:seismic_unbraced=yes/no/inconclusive/score
building:seismic_cripple_wall=yes/no/inconclusive/score
building:seismic_out-of-plane_setback=yes/no/inconclusive/score
building:seismic_in-plane_setback=yes/no/inconclusive/score
building:seismic_short_column_pier=yes/no/inconclusive/score
building:seismic_split_levels=yes/no/inconclusive/score

( ... additional other Table B-3,4,5,6 characteristics ... )

building:seismic_mitigation_status=yes/no/unknown
Building:seismic_FEMA
All, one, or some of these might apply to a given building. The last two are important, international users may want to use the standards I mentioned in my posts. What conceivable benefit is there to establishing only one key and ignoring all the other equivalent and possibly more important characteristics? If they are tagging anyways, the marginal cost of noting the others besides soft_story are very marginal. On the other hand, in this situation, having incomplete data is far worse than none at all - you could have a hundred buildings with only 3 soft story ones, the others could have ALL the other attributes but not soft story, and the resulting map would completely fail. ( See Spatial Data Quality)
Although you did well referencing the FEMA document, you should direct them to the salient sections that inform their task, like the Appendices and tables.
I think this is a valuable project but it's a different one than the one I'm proposing. You're proposing a full seismic assessment data model. I'm proposing to a) legalize the de-facto status, with 13k tags already entered and b) to allow to enter some more based on a simple model, which is in use by many building codes. What you suggest should be proposed separately, they don't overlap at all and can co-exist. --Smaffulli (talk) 23:38, 24 January 2019 (UTC)

I have no idea what the value 're-enforced' means differently from the value 'no', why not simply change the value 'yes' to 'no'? Warin61 (talk) 22:08, 2 February 2019 (UTC)

Thank you, I'll clarify. Basically reinforced means that work has been done to put the building up to code, "patched" so to speak. The value "No" is to identify buildings that never had soft-storeys.

How to Map

Most OSM wiki pages have a section on 'how to map'. It instructs the mapper on what to do. There is nothing in this proposal that suggests 'how to map'. I'd think that a new section on 'how to map' will help people understand the proposal. The section should contain something along the lines of "On a building that has been assessed as having a 'soft storey' add the tag building:soft_storey=yes. If the building building that has been assessed as having no 'soft storey' add the tag building:soft_storey=no. " etcetera. This should be the first statement, keep it simple. Explain how or reference documents for how the assessment is made could come after it. But first tell them what the values mean. Warin61 (talk) 22:08, 2 February 2019 (UTC)

It looks like soft_storey=* (without the "building:" prefix) is also widely used: taginfo link. I assume that as part of this proposal we should declare that soft_storey=* is incorrect tagging, and building:soft_storey=* should be used instead. --Alan (talk) 05:58, 11 February 2019 (UTC)