Miami Beach, Champlain Towers South apartment building collapse, Part 11 54

[SFCharlie]

A continuation of our discussion of this failure. Best to read the other threads first to avoid rehashing things already discussed.
Miami Beach, Champlain Towers South apartment building collapse
Miami Beach, Champlain Towers South apartment building collapse, Part 02
Miami Beach, Champlain Towers South apartment building collapse, Part 03
Miami Beach, Champlain Towers South apartment building collapse, Part 04
Miami Beach, Champlain Towers South apartment building collapse, Part 05
Miami Beach, Champlain Towers South apartment building collapse, Part 06
Miami Beach, Champlain Towers South apartment building collapse, Part 07
Miami Beach, Champlain Towers South apartment building collapse, Part 08
Miami Beach, Champlain Towers South apartment building collapse, Part 09
Miami Beach, Champlain Towers South apartment building collapse, Part 10


SF Charlie
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[gonefishing2]

I too would like to understand Surfside’s Storm Drainage System, and was the $400K split all spent for on the system showing on P1and P2. If that is where Surfside’s $200K share went, then Surfside just gave the Developer $200K?

After tub was dried out, the in rush with high tide seem to come from the West side of CTS, or from under Collins Stormwater system. So it would appear, it may be back flow from a flooded under designed street side system or just an old leaky system?

Edit: It is hard for me to understand how the CTS storm water holding area would work with a higher water table and no where for water to go into well?

Edit2: Where do you put storm water when water table is so high on flat near sea level islands?

In our city frequent weekly 100 year rain events cause storm runoff to enter leaky sanitary sewer system and cause flooding of both in low areas. I am on a mountain, so the back flow never seems to reach my elevation, but what do u do in Surfside? Pump it back into ocean in a never ending battle?

 

[Demented]

Pump stations typically pump it out to the intercoastal waterway from east to west on the island side. A few threads back Santos81 was mentioning the pump stations being inadequate for that area. Up here in the Palm Beaches our pump stations go out quite regularly especially around times of heavy rain, I can only assume Miami-Dade is the same. They just simply are running all the time, but we do have enough redundancy built in that it's not; lessons from Irene.


Precision guess work based on information provided by those of questionable knowledge

 

[FacEngrPE]

The attachment which contains the following statement may be applicable to the study of the storm drain system.

Community Stormwater Management
Design storms with 5-year return periods are required in the design of residential and commercial stormwater management systems, and full onsite retention of design storm runoff is required if at all possible (Miami-Dade Department of Environmental Resources Management, 1980). The implication of this requirement is that the stormwater management system must be capable of accepting runoff from 5-year storms of any duration.

Five-year storms with a 1-hour duration typically are used in assessing the capacity of onsite drainage structures, such as exfiltration trenches. ...

A cistern able to hold the rain from a 5 year storm (2.88 per 1 hour and 6.67 per 24 hours) is huge. These rules were placed into effect in in effect as of 1980, which was the construction year.

 

[MaudSTL]

Something like this.

Wonder who(m) will be groping inspecting those columns?

You just took me back to 1986. I was a minority hire into outside plant engineering at the phone company. I thought I had time traveled back to 1950. I won’t regale you with all the things my colleagues did to get me to quit. But their tactics didn’t work because I had decided that I would outlast them…and I did. After the black guys, the Korean-American guy, and the other white woman started at our office, I was ready to move into a different department. But before I left, my state president personally busted my boss’s boss for what he did to me, and my boss got transferred to a job he hated. Neither of them finished their careers at the phone company. Ah, those were the days!

35 years later, I would have thought we would have gotten a little farther than we have. If any of you have daughters who find themselves in a similar predicament, I hope they too will be sure to figure out how to get even instead of mad.

 

[SFCharlie]

I personally apologize for provoking the continuation of this stream of thought.

SF Charlie
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[gonefishing2]

Thanks FacEngrPE, that was an interesting read. So, if I did my math right, CTS should have been able to hold 51,593 gallons of rain locally, or handle the first 1" of rain fall from the 1.9 acre site. What CTS had was a 3000 gallon retention system that drained into a 24" box feeding an undefined well. So it appears to me, there is NO WAY CTS storm system is anywhere close to sufficient capacity to meet code requirements at the time.... Consistent with the trend for CTS.

 

[gonefishing2]

Maud, I did not mean to offend anyone with my comment, nor was there any intent to imply I condoned what you implied happened to you in 1986.

 

[SFCharlie]

"I am not a female architect. I am an architect"

Dorte Mandrup has imagined 'The Hinge', a landmark transition between the new urban area Aarhus Ø and the historic town.

SF Charlie
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[AusG]

Ditto, apologies. suitably chastened.

 

[Optical98]

SF Charlie

That looked so Sci-Fi I had to look up

https://www.designboom.com/design/nasa-astronauts-what-happens-to-concrete-in-space-09-09-2019/

 

[SFCharlie]

...and speaking of "other weighty matters"...

Another image from Dorte Mandrup's portfolio...

Curved buildings are noted for their resistance to earthquakes because they are not excited by shaking in any one axis.
To me, this image makes a statement that slender pillars can carry immense weight.
Thank you, Maud, for returning my focus to columns that can help protect against slab shear punch-through.

SF Charlie
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[Demented]

You just took me back to 1986. I was a minority hire into outside plant engineering at the phone company. I thought I had time traveled back to 1950. I won’t regale you with all the things my colleagues did to get me to quit. But their tactics didn’t work because I had decided that I would outlast them…and I did. After the black guys, the Korean-American guy, and the other white woman started at our office, I was ready to move into a different department. But before I left, my state president personally busted my boss’s boss for what he did to me, and my boss got transferred to a job he hated. Neither of them finished their careers at the phone company. Ah, those were the days!

35 years later, I would have thought we would have gotten a little farther than we have. If any of you have daughters who find themselves in a similar predicament, I hope they too will be sure to figure out how to get even instead of mad.

Apologies for any offense. I've got unicorns and rainbows all over my station of pink painted tools. No offense was intended at all, trust me.


Precision guess work based on information provided by those of questionable knowledge

 

[Demented]

Thanks FacEngrPE, that was an interesting read. So, if I did my math right, CTS should have been able to hold 51,593 gallons of rain locally, or handle the first 1" of rain fall from the 1.9 acre site. What CTS had was a 3000 gallon retention system that drained into a 24" box feeding an undefined well. So it appears to me, there is NO WAY CTS storm system is anywhere close to sufficient capacity to meet code requirements at the time.... Consistent with the trend for CTS.

Ocean to the East, Intercoastal waterway to the West. Retention systems requirements kinda get altered around those. I am not sure as to which extent that is allowed, but it is a factor that could actually put the retention system in spec with the fault being on the towns side of the system.

Where I'm at, we have swells that feed into a retention pond that overtops into culverts that drains straight into the intercoastal. Roughly a 45 acre property with 80k gallon or so retention pond. *shrugs*

 

[Demented]

Sec. 34-43. - Design standards.
To comply with the performance standards set forth in this division, the proposed stormwater management system shall conform to the following design standards:

(1)Detention and retention systems shall be designed to comply with the Stormwater Management Manual adopted by Dade County.
[highlight yellow](2)To the maximum extent practicable, natural systems shall be used to accommodate stormwater.[/highlight]
(3)The proposed stormwater management system shall be designed to accommodate the stormwater that originated within the development and stormwater that flows onto or across the development from adjacent lands.
(4)The proposed stormwater management system shall be designed to function properly for a minimum 20-year life.
(5)The design and construction of the proposed stormwater management system shall be certified as meeting the requirements of this article by a professional engineer registered in the state.
(6)No surface water may be channelled or directed into a sanitary sewer.
[highlight yellow](7)The proposed stormwater management system shall be compatible with the stormwater management facilities on surrounding properties or streets,[/highlight] [highlight green]taking into account the possibility that substandard systems may be improved in the future.[/highlight](8)The banks of detention and retention areas shall be sloped to accommodate, and shall be planted with, appropriate vegetation.
(9)Dredging, clearing of vegetation, and deepening, widening, straightening, stabilizing or otherwise altering natural surface waters shall be minimized.
(10)Natural surface waters shall not be used as sediment traps during or after development.
(11)Water reuse and conservation shall, to the maximum extent practicable, be achieved by incorporating the stormwater management system into irrigation systems serving the development.
(12)The grading of all properties located west of Collins Avenue shall be designed so that the average grade elevation of the lot, other than the building's footprint, shall not exceed the average elevation along the center line of the street pavement on which it fronts. Proposed elevations along the property boundaries shall match the adjacent lands, and cause no storm water runoff to flow across any of the property's boundaries, as provided in subsection (3) above.
(13)A Florida Registered Professional Engineer shall provide certification of conformance with these design standards of the project's grading design at the time of submittal for approval of construction documents, at completion and prior to occupancy.
(Code 1960, § 6B-27(b); Ord. No. 1442, §§ 1, 2, 9-9-03)

@All About Money
It does appear CTS was in complience.

 

[Spartan5]

https://www.newcivilengineer.com/la..._NCE_EDI_ALL_DAILY_100821&deliveryName=DM4039

That is all still one of the more concerning aspects of all of this to me. The structural consultant was being paid >$500K to inspect and analyze the integrity of the building, and design the repairs for it and had been working on this for several years. Either the flaw that allowed this was so hidden, or they should have seen it. Or was this like FIU where it was staring everyone right in the face but they didn’t want to acknowledge it?

 

[CE3527]

Insurance companies doing what insurance companies do best. They love taking your money, but always find ways to not pay out their own. I don't see how the insurance companies can refuse to cover the engineer at this point, until the cause of the collapse is better identified. Even then, Morabito didn't have control of the timing when the work got done, and based on the evidence out there in terms of visible surface damage, there was no precedence to believe this building faced an imminent collapse. Perhaps they share some liability, but they did not design, build, or maintain the structure that collapsed.

 

[SFCharlie]

The commission voted unanimously to pursue legal action against Miami-Dade County, the court-appointed receiver for Champlain Towers South, and any other entities that are preventing the town's hired expert — Allyn Kilsheimer of KCE Structural Engineers — from accessing the site where the collapse occurred, as well as from the warehouses where debris from the site is being stored.

Surfside condo collapse: Once together in mourning, Surfside now fuming; aims to sue county


SF Charlie
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[Reverse_Bias]

Insurance companies doing what insurance companies do best. They love taking your money, but always find ways to not pay out their own. I don't see how the insurance companies can refuse to cover the engineer at this point, until the cause of the collapse is better identified. Even then, Morabito didn't have control of the timing when the work got done, and based on the evidence out there in terms of visible surface damage, there was no precedence to believe this building faced an imminent collapse. Perhaps they share some liability, but they did not design, build, or maintain the structure that collapsed.

Not the building itself. There was reason to believe the pool deck could collapse at any moment. That alone could have been fatal if someone were under it.

 

[arbitraria]

In a geographical area such as this one. is the prevailing notion with regard to stormwater management more or less "meh"? Only designing for a 5-year storm seems insane to me, but I'm in the northeast (land o'regulations, I suppose) so the natural conditions are a wee bit different. I realize the coast and bay are in close proximity to the CTS site - in a big storm / hurricane situation, is it just a given that the stormwater will converge with those bodies of water, so any attempts at large-scale diversion are futile?

I'm trying to get an accurate gauge for what is standard in this area, the system seems undersized but again these environmental conditions diverge from what I'm used to. Can a well of indeterminate depth adequately accept so much discharge? Such a narrow strip of land relative to all that water has to be under a decent amount of subsurface pressure from all sides, it just seems like there wouldn't be anywhere for this water to go. The outlet's proximity to the structure feels like an invitation for trouble. If stormwater can't adequately discharge, just how backed up would all of those drains get? Aside from obvious issues at the base of the structure, is it possible that there was a pressure/leak condition inside the walls from the rain water leaders?

I have to go back and re-read the articles that describe the developers' contribution to the town's utility upgrades - I had assumed sanitary when they talked about insufficient sewer capacity. If it was in fact stormwater, CTS had to pay to get the town's system up to date to allow for development, but they never actually had to connect to it? It makes sense that allowing for higher-density structures would necessitate a larger system, I'm just baffled that at least one of these towers would then be exempt from integration.

 

[raymiepo]

For those interested in info about CTS injection well >

Interactive map for:
Underground Injection Control (UIC) Class V Non-ASR Wells
(ASR) Aquifer Storage and Recovery.

https://ca.dep.state.fl.us/mapdirect/?focus=uic

A couple of things I've discovered:

1. CTEast has two wells.
2. Mirage on the Ocean, 8925 Collins Ave, has one for stormwater drainage with a construction complete date of 01/13/1982.
3. Surf Club, 9011 Collins Ave, has one for swimming pool drainage with a construction complete date of 06/07/1977.
4. CTSouth and CTNorth have none showing on the map.
5. Wells, in the area, are around 80 to 90 ft. deep.

I will note that there is a disclaimer:
"The existence and accuracy of the point locations are being verified. Positional accuracy may vary from feature to feature. Information contained herein is provided for informational purposes only. The State of Florida, Department of Environmental Protection, Bureau of Water Facilities Regulation, Underground Injection Control Program, provides geographic information systems (GIS) data and metadata with no claim as to the completeness, usefulness, or accuracy of its content, positional or otherwise. The data could include technical inaccuracies and typographical errors."

My questions now are:
Did CTS ever have permitted, inspected, and recorded wells as drawn on the plans?
Where/into what did the 18" storm for CTS discharge?
Does CTN have permitted, inspected, and recorded wells?