FORENSIC ANALYSIS OF COLLAPSE OF SURFSIDE CONDMINIMUM, MIAMI

International Research Journal of Engineering and Technology (IRJET) e-ISSN:2395-0056

Volume: 09 Issue: 08 | Aug 2022 www.irjet.net p-ISSN:2395-0072

FORENSIC ANALYSIS OF COLLAPSE OF SURFSIDE CONDMINIMUM, MIAMI

1Department of Civil Engineering, Saintgits College of Engineering, Kottayam 2Assistant Professor, Department of Civil Engineering, Saintgits College of Engineering, Kottayam ***

Abstract - Forensic engineering is a process of locating failures and providing solutions or preventive solutions This used to find problems or know problems that may arise due to utility and act accordingly before failure occurs. This helps us uncover many hidden facts or discoveries in the performance of a building in different service conditions and during construction. Forensic engineering can benefit for new buildings and flats providing elements to include into the design that will enhance life-cycle and lower maintenance costs. The process results in enhancements that solve immediate problems and bring about cost savings and efficiencies for the long term. This paper is a preliminary analysis of the collapse of the 40-year Building in Miami. This reveals the possible trigger and stressor of the building collapse on 24th June

Key Words: Forensic, Engineering, Diagnostic, Consolidation

1. INTRODUCTION

Forensicengineeringis a processoflocatingfailuresand providing solutions or preventive solutions This used to find problems or know problems that may arise due to utilityandactaccordinglybeforefailureoccurs

The lessons from forensic engineering, coupled with a reliability-centred maintenance process, enable a facility manager to adjust the scope and frequency of periodic maintenance and preventive maintenance based on the pastperformanceofexistingequipment.

Champlain Towers South Condominium , a 12-13 storey 40-year old undergone a sudden partial collapse on June 24.This building is located near the Miami suburb. The building contained 136 apartments in which 55 apartmentshavecollapsed.

1.1 Detection Devices

Forensic engineers use both Non-invasive tests and invasive tests for the investigation. The non-destructive methods include a detailed visual examination by an expert and the use of electromagnetic detection equipment, infrared imaging, ground-penetrating radar, andX-rayimaging.

Invasive methods of test for investigation cut, break and tear specimen to inspect it. Tools such as borescopes, fluoroscopes, and video scopes can minimize the amount of material that must be removed for inspection. The benefit of the analysis is, it provide the reason for failure orstressorcomponentleadingtofailure

2.INVESTIGATION BY NIST

The Forensic study is conducted by the National Institute ofStandardsandTechnology(NIST).TheNISTteamwill:

Establishthelikelytechnicalcause

Checkbuildingstandards,codesandpractices;

Actionrequiredtoimprovesafety

2.1 Test Conducted

Remotesensingisusedforwherepiecesofevidencewere locatedinthedebrispile.LIDAR-usedformappingofthe debrissiteand It isused fromnearbyapartments. Timelapse cameras are used to record all the details during investigationsinthechangingscene.

International Research Journal of Engineering and Technology (IRJET) e-ISSN:2395-0056

Volume: 09 Issue: 08 | Aug 2022 www.irjet.net p-ISSN:2395-0072

TheNISTteamcontinuestorefineandupdateprocedures for evidence identification, marking and tagging and has collected more than 200 building elements including columns, beams and pieces of a concrete slab. All the evidencearestoredinMiamiPoliceDepartment

NIST will be deploying an electronic evidence tagging systemthatusesRFIDchipssothatelectronicrecordsare associatedwitheverypieceofevidencecollectedasshown inFig.1&Fig.2.

-2

NIST conducts geologic studies in the foundation region The subsurface investigation groundwater. The laboratory testing of the soil and rock. Field testing will bring out the nature and image of the foundation region,subsurfacesoilsandsoilbelowitalso.

Fig -3: A geophysics specialist performs non-destructive testing,usinganimpulseecho,tosupporttheevaluationof theintegrityofthefoundation.

NISTisusesnon-invasivetestlikeultrasonicpulsevelocity to evaluate the quality and strength of the concrete specimen. The Fig. 3 and Fig.4 shows use of UPV test conductedbyNISTEngineers

International Research Journal of Engineering and Technology (IRJET) e-ISSN:2395-0056

Volume: 09 Issue: 08 | Aug 2022 www.irjet.net p-ISSN:2395-0072

3. PRELIMINARY

ANALYSIS OF

CHAMPLAIN TOWER COLLAPSE.

The collapse of buildings can be due to many reasons. Many variables come into place that can influence a building collapse. Some reasons could be overloading, under-maintainedbuilding,badengineeringpracticesetc.

ChamplainTowerSouthcollapseahavemanystressorsin place.ThisSeminarmainlydealswiththreeissues:

LeakageIssues. 

FoundationalIssues. 

StructuralIssues.

Otherissuesincludemaintenanceissues,negligenceofdue process, not maintaining quality standards and assurances.

3.1 Leakage Issue

3.1.1 Leakage In Pool Deck

Miami faces hurricanes, storms and heavy rains every year.Ina placewhereisplentyofrain,ifproperdrainage is not provided it will very detrimental for any infrastructure. In this case, the pool deck didn’t have proper drainage which caused ponding of water. This water will enter into the crack of concrete which will cause rusting of reinforcements. This cause leakage cause dripping waterfrom the ceilingofthe garage asshown in Fig.5.

Fig -6:Drippingwaterfromtheceilingofthegarage.

Duetothisleakage,therewerespallingofconcretewhich waspointedoutinthe re-certificationreportlikeinFig. 6 andFig.7

Fig -5:Leakageofwaterinthecracksofconcretefromthe pooldeck.

MorabitoConsultantswhodidthe40-yearre-certification process in 2018 claimed that if this kind of leakage is not solved immediately concrete deterioration will expand exponentially.

Fig -7:Spallingofconcretefromgaragecolumnsand garagefloor.

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The steps taken to solve these leakage issues wasn’t efficient and did poor work from the management to cut costwasstatedbyasurvivor.

3.1.2 Waterproofing Of Planter Box

There are many planter boxes in the compound of the building which provide good aesthetics. If proper waterproofingisnotdoneintheseboxescancauseunseen deterioration also it will be very difficult to predict or detectanycorrosionunderneaththoseplantsasshownin Fig.4.4.

lead other structural problems. Differential settlement happenswhenthesoilstrataunderthebuildingbeginsto change ,which in turn shifts the position of the building. This can be caused by drought conditions, the root systems of mature trees, flooding, poor drainage, frost, broken water lines, vibrations from nearby construction orpoorlycompactedfillsoil.

The study from a researcher at Florida International University found that the area around the building as in the graph shown in Fig. 10 constructed on reclaimed wetlandshadbeensinkingatarateoftwomillimetresper year for the last three decades. There is the possibility to causeadifferentialsettlement.

3.2 Foundational Issue

3.2.1 Pile Issue

Initially,thetypeofproposedpilewasprecastpileswhich had a load-carrying capacity of 50 tonnes per pile. Later rightbeforetheconstruction,thetypeofpilewaschanged Pressure Injected Footing piles or PIF piles. These PIF pileshavea load-carryingcapacityof150tonnesperpile. This is to reduce the number of precast piles thereby cutting costs. Change of type of piles right before the construction phase is not a common practice. The Figure ofpilesisasshowninFig.9.

`

Fig -10:VerticaldisplacementnearChamplainTowers.

3.2.3 Consolidation Settlement

Consolidation settlement is a time-dependent natural process of fully saturated soil due to expulsion of water from the voids and compaction is an instantaneous artificial process of partially saturated soil due to expulsionofairfromvoids.

The whole buildingisontopofsmall columnsextending from the foundation. These columns act as a box. During monsoon in the water table rise to the floor of the garage asshowninFig.11

Fig -9:PIFpilesatleft,precastpilesattheright.

3.2.2 Differential Settlement

Uneven settlement of soil strata at different pats of the building can cause differential settlement and can may

Fig -11:Watertableduringthemonsoonperiod

International Research Journal of Engineering and Technology (IRJET) e-ISSN:2395-0056

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Then during summer, the water table goes down along withthesoilnearthecolumns,Hencecreatingavoidnear thefoundationasshowninFig.12.

Fig -12:Thewatertablegoesdownthefollowingsummer. Then the following monsoon period the water table rise fillingthevoidinthefoundationasshowninFig.13

Fig -15:Waterloggedbeneaththefloorofthegarage. Columnsinthisareawherewatergetlogged,columnpulls water up like sponge cause rusting of reinforcements as showninFig.15andFig.16.

Fig -13:Thewatertablerisesinsubsequentmonsoon. This waterlogged in this area can cause deterioration of concrete as shown in Fig. 14. Further causing to form sinkholes.

Fig -16:Enhancedimageofwaterpullingintocolumns.

3.3 Structural Issue

3.3.1 Punching Reinforcements

The tower is constructed in a flat slab construction method. In the collapse of the building, it revealed that there were not any punching rebars present in the building. Punching shear happens when high localized forcesonRCCslab,therehighproximityforhighlocalized loads on flat slab structure. The failure is due to shear. This type of failure is very dangerous as it cannot be known or seen before failure, so for safety contractors provide punching rebars. The absence of punching rebars isshowninFig.17.

Fig -14:Possibledeteriorationofconcrete.

Fig -17:Nopunchingrebars

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3.3.2 Columns

Certain column to column-span is very higher than usual standards.Itwasalsopointedoutcertaincolumnscarried lessreinforcementthaninthestructuraldrawings.

3.3.3 How it Happened

The first area to collapse is the pool deck. This column punchedthroughthepooldeck.Thisisduetocorrosionin thepooldeckmentionedintheearlierchapter.

Fig -18:Punchingofcolumnsatthepooldeck.

This is punching caused the sinking of the pool deck slab along with its beam. Hence pulling a main structural memberasshowninFig.18

Fig -20:Bucklingofcolumn.

Moments before the collapse of the building, a bystander was able to capture a video of the collapsed roof of the garageandabrokenpipewithwaterfalling.Theextentof thecollapseisstillunknownasshowninFig.21

Fig -19:Pullingofslabfromthecolumns.

The corresponding beams connected to columns of the buildingwhichalreadylappedintothecolumnsgetpulled off or ripped off the columns, hence causing buckling of columns. The first two columns to collapse is column 13 column 14.Rest of the building collapse like a chain reactionasshowninFig.19andFig.20.

Fig -21:Bigchunksofconcreteonthefloorofthegarage.

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3.3.4 Shear Wall

Shear wall is a structural member in a RCC structure These structural members are used resist lateral forces such as wind forces and seismic forces They are used in tall buildings Asheightof buildingincreases,the effect of wind forces increases There codes of practices that limit onhorizontalsway.

The main reason why the rest of the building didn't collapseisthatthewestsectionofthebuildingconsists of shear walls containing the elevator shaft. This wall protectedtherestofthebuilding asshowninFig. 22This wall is a strong element, when the rest of the building collapses,itissimplytornofffromtheshearwall.



Thishelpsusuncovermanyhiddenfacts.



Discoveries in the performance of a building in differentserviceconditionsandduringconstruction.



Forensic engineering bring out mistakes or wrong procedures that may be corrected to aid in constructionsofnewbuildings



Providing recommendations for elements to incorporate into the design.It will enhance life-cycle rates, lower maintenance costs, solve immediate problems, cost savings and provide long term efficiencies.



Forensic engineering will provide a holistic view of building collapse followed by the stressors that may occurinneighbouringbuildings



This brings out new standards and greater importanceinqualitycontrolandqualityassurance.

REFERENCES

[1] X. Lu, H. Guan, H. Sun, Z. Zheng, Y. Fei, Z. Yang, L. Zuo (2021), “A preliminary analysis and discussion of the condominium building collapse in surfside, Florida, US, June 24, 2021”, Frontiers of Structural and Civil Engineering 2021.15,1097–1110.

[2] Morabito Consultants (2018), Structural Field Report of Champlain Tower South Condominium. unpublished.

[3] S.P.Brady(2014),Effectivelyrespondingtostructural engineering failure: Expertise and cognitive entrenchment. Journal of Performance of Constructed Facilities,28(5),04014020.

[4] S. P. Brady (2012), Role of the forensic process in investigating the structural failure. Journal of performance of constructed facilities,26(1),2–6.

[5] N. J. Delatte (2009), Beyond Failure Forensic Case Studies for Civil Engineers, Published by American Society of Civil Engineers.

4. CONCLUSION

ThispaperdealswiththecollapseoftheChamplaintower south building. It brings out the grounds of collapse and triggers which may have caused the collapse. Some of them are leakage issues caused by the improper drainage facilities and ignorance of the management in solving the leakage issue, not providing punching rebars for flat slab construction.Notdoingproperqualitycontrolandquality assurance. Hence forensic engineering in the civil field is veryimportant.

[6] Forensic Engineering, (2005) Available:https://buildings.com/articles/36180/fore nsic-engineering

[7] J. Porter, Building Integrity, Champlain Tower South,Available: https://www.youtube.com/playlist?list=PLQw1wzpZ L_lovGG_jMIDwfS_a9uaGrdh-

[8] National Institute of Standards and Technology, Available: https://www.nist.gov/