WHEN TECHNOLOGY FAILSWHEN TECHNOLOGY FAILS

STRUCTURESSTRUCTURES

PRESENTED BY AL TICE, P.E.PRESENTED BY AL TICE, P.E.

OUTLINEOUTLINE

STRUCTURAL BACKGROUNDSTRUCTURAL BACKGROUNDBRIDGE FAILURESBRIDGE FAILURESBUILDING FAILURESBUILDING FAILURESCURRENT PRACTICECURRENT PRACTICEFIRST FIRST –– SOME HISTORICAL INFOSOME HISTORICAL INFO–– TAPETAPE

STRUCTURAL BACKGROUNDSTRUCTURAL BACKGROUND

STRUCTURE STRUCTURE –– A SYSTEM OF A SYSTEM OF CONNECTED PARTS USED TO CONNECTED PARTS USED TO SUPPORT A LOADSUPPORT A LOADEXAMPLES:EXAMPLES:–– BRIDGESBRIDGES–– BUILDINGSBUILDINGS–– TOWERS TOWERS –– TANKSTANKS

KEY COMPONENTS FOR KEY COMPONENTS FOR DESIGNDESIGN

MATERIALSMATERIALSLOADSLOADS

MATERIALSMATERIALS

STRENGTHSTRENGTHDEFLECTIONDEFLECTION

LOADSLOADSDEADDEAD–– WEIGHT OF MATERIALSWEIGHT OF MATERIALS–– WEIGHT OF PERMANENT FIXTURESWEIGHT OF PERMANENT FIXTURES

LIVE (use)LIVE (use)–– PEOPLEPEOPLE–– CONTENTSCONTENTS

LIVE (environment)LIVE (environment)–– WINDWIND–– RAIN, SNOWRAIN, SNOW–– EARTHQUAKESEARTHQUAKES

STRUCTURAL ELEMENTSSTRUCTURAL ELEMENTS

BEAMS/GIRDERSBEAMS/GIRDERSCOLUMNSCOLUMNSTIE RODSTIE RODS

STRUCTURE TYPESSTRUCTURE TYPES

TRUSSESTRUSSES

CABLES AND CABLES AND ARCHESARCHES

FRAMESFRAMES

SURFACE (SHELLS)SURFACE (SHELLS)

STRUCTURAL DESIGNSTRUCTURAL DESIGN

MATCH LOADS TO MATERIAL MATCH LOADS TO MATERIAL CAPABILITIESCAPABILITIESCODES PROVIDE LIMITSCODES PROVIDE LIMITSITERATIVE PROCESSITERATIVE PROCESSCONNECTIONS ARE CRITICALCONNECTIONS ARE CRITICAL

BRIDGESBRIDGESARCH

TRUSS

SUSPENSION

BEAM AND PIERS

BRIDGE FAILURESBRIDGE FAILURES

QUEBEC QUEBEC –– 1907, 19161907, 1916TACOMA NARROWS TACOMA NARROWS –– 19401940KINGS BRIDGE KINGS BRIDGE –– 19621962POINT PLEASANT POINT PLEASANT –– 19671967MIANUS IMIANUS I--95 95 –– 19831983SCHOHARIE SCHOHARIE –– 19871987

QUEBEC BRIDGE COLLAPSESQUEBEC BRIDGE COLLAPSES1907 and 19161907 and 1916

PLANNED AS STEEL TRUSS WITH PLANNED AS STEEL TRUSS WITH CANTILEVER CENTER SPAN 1500CANTILEVER CENTER SPAN 1500’’LONGLONG

DESIGNED BY PROMINENT DESIGNED BY PROMINENT ENGINEERENGINEER

1907 FAILURE1907 FAILUREPARTLY COMPLETED PARTLY COMPLETED CENTER SECTION CENTER SECTION COLLAPSED KILLING COLLAPSED KILLING 80.80.EXCESSIVE EXCESSIVE DEFLECTION NOTED DEFLECTION NOTED DAY BEFOREDAY BEFOREENGINEER IN NEW ENGINEER IN NEW YORK AND DIDNYORK AND DIDN’’T GET T GET ADVICE BACK TO SITE ADVICE BACK TO SITE IN TIMEIN TIME

CAUSESCAUSES

DESIGN PUSHED UP ALLOWABLE DESIGN PUSHED UP ALLOWABLE STRESSSTRESSLOADS WERE UNDERESTIMATEDLOADS WERE UNDERESTIMATEDSTRUCTURE OVERSTRESSEDSTRUCTURE OVERSTRESSEDINADEQUATE BRACINGINADEQUATE BRACINGARROGANT ENGINEER OUT OF ARROGANT ENGINEER OUT OF TOUCH WITH SITE AND TOUCH WITH SITE AND CONSTRUCTIONCONSTRUCTIONPERSONNEL ON SITE NOT PERSONNEL ON SITE NOT KNOWLEDGEABLE OF DESIGNKNOWLEDGEABLE OF DESIGN

LESSONS LEARNEDLESSONS LEARNED

THOROUGH CHECKING OF DESIGN THOROUGH CHECKING OF DESIGN CALCULATIONS AND LOAD CALCULATIONS AND LOAD ASSUMPTION NEEDEDASSUMPTION NEEDEDTESTING NEEDED IF WANT TO TESTING NEEDED IF WANT TO EXCEED ACCEPTED STRESS LEVELSEXCEED ACCEPTED STRESS LEVELS

1916 COLLAPSE1916 COLLAPSEBRIDGE REDESIGNED BRIDGE REDESIGNED BY DIFFERENT BY DIFFERENT ENGINEERSENGINEERSBUT BUT –– STILL USED STILL USED ASSUMPTIONS OF ASSUMPTIONS OF STRESSES ABOVE STRESSES ABOVE NORMALNORMALDIFFERENT METHOD DIFFERENT METHOD TO INSTALL CENTER TO INSTALL CENTER SPAN USED SPAN USED –– LIFT LIFT INTO PLACEINTO PLACEDURING LIFTING, SPAN DURING LIFTING, SPAN CAME APART AND CAME APART AND FELL INTO RIVER, FELL INTO RIVER, KILLING 11KILLING 11

1916 CAUSE1916 CAUSE

CAUSE ATTRIBUTED TO OVERSTRESS CAUSE ATTRIBUTED TO OVERSTRESS IN LIFT SPAN MEMBERS.IN LIFT SPAN MEMBERS.

AGAIN AGAIN –– STUDIES SHOWED THAT STUDIES SHOWED THAT MATERIALS IN SPAN WERE MATERIALS IN SPAN WERE OVERSTRESSED.OVERSTRESSED.

1917 – REDESIGNED AND COMPLETED

QUEBEC IMPACTSQUEBEC IMPACTS

LED TO MORE DETAILED CODES AND LED TO MORE DETAILED CODES AND STANDARDS STANDARDS LED TO INCREASING ACCEPTANCE OF LED TO INCREASING ACCEPTANCE OF THE AMERICAN SOCIETY FOR THE AMERICAN SOCIETY FOR TESTING MATERIALS (ASTM) FOR TESTING MATERIALS (ASTM) FOR MATERIAL STANDARDS.MATERIAL STANDARDS.ENGINEERS BEGAN TO DO MORE ENGINEERS BEGAN TO DO MORE MATERIAL TESTING.MATERIAL TESTING.

TACOMA NARROWS TACOMA NARROWS -- 19401940

SUSPENSION BRIDGE 2800SUSPENSION BRIDGE 2800’’ SPANSPANDESIGNED BY EXPERIENCED DESIGNED BY EXPERIENCED ENGINEERSENGINEERSPUSHED ENVELOPE TO CREATE PUSHED ENVELOPE TO CREATE ““STREAMLINEDSTREAMLINED”” APPEARANCE APPEARANCE RESULT WAS A THIN, LIGHT SPANRESULT WAS A THIN, LIGHT SPAN

THE FAILURETHE FAILURE

WINDS CAUSED BRIDGE TO BUCK WINDS CAUSED BRIDGE TO BUCK AND TWIST AND TWIST ROLL TAPE!ROLL TAPE!

CAUSECAUSE

OBVIOUSLY WIND CREATED OBVIOUSLY WIND CREATED EXCESSIVE MOVEMENT AND STRESS.EXCESSIVE MOVEMENT AND STRESS.ONE CABLE SLIPPED OUT OF PLACE ONE CABLE SLIPPED OUT OF PLACE CAUSING THE FINAL COLLAPSE BY CAUSING THE FINAL COLLAPSE BY ALLOWING TWISTING INSTEAD OF UP ALLOWING TWISTING INSTEAD OF UP AND DOWNAND DOWN

IMPACTSIMPACTS

BRIDGE NOT REPLACED TIL 1950 BRIDGE NOT REPLACED TIL 1950 LED TO DEVELOPMENT OF LED TO DEVELOPMENT OF AERODYNAMICS AS ENGINEERING AERODYNAMICS AS ENGINEERING DISCIPLINEDISCIPLINELED TO WIND TUNNEL TESTING OF LED TO WIND TUNNEL TESTING OF MODELS FOR ALL LARGE BRIDGESMODELS FOR ALL LARGE BRIDGES

KINGS BRIDGE, MELBOURNE KINGS BRIDGE, MELBOURNE AUSTRAILIA AUSTRAILIA -- 19621962

A CONCRETE DECK ON HIGHA CONCRETE DECK ON HIGH--STRENGTH WELDED PLATE GIRDERSSTRENGTH WELDED PLATE GIRDERS2300 FOOT LONG BRIDGE2300 FOOT LONG BRIDGECOMBINED SIMPLE SPANS WITH COMBINED SIMPLE SPANS WITH CANTILEVER SPANSCANTILEVER SPANSUSE OF HIGHUSE OF HIGH--STRENGTH STEEL NOT STRENGTH STEEL NOT COMMON THEN AND WELDING OF THE COMMON THEN AND WELDING OF THE STEEL USED WAS UNTRIEDSTEEL USED WAS UNTRIED

FAILUREFAILURE

OCCURRED ON VERY COLD NIGHTOCCURRED ON VERY COLD NIGHTTWO SPANS DROPPED 1 FOOT BUT TWO SPANS DROPPED 1 FOOT BUT ADJACENT WALLS PICKED UP LOAD ADJACENT WALLS PICKED UP LOAD AND PREVENTED TOTAL COLLAPSE.AND PREVENTED TOTAL COLLAPSE.NO DEATHS OR INJURIES DUE TO NO DEATHS OR INJURIES DUE TO NIGHTNIGHT

CAUSECAUSECRACKING AT WELDS FOUND AT MOST CRACKING AT WELDS FOUND AT MOST CONNECTIONS. CONNECTIONS. CRACKS OCCURRED IMMEDIATELY AFTER CRACKS OCCURRED IMMEDIATELY AFTER WELDING AND WERE NOT DETECTED BY WELDING AND WERE NOT DETECTED BY INSPECTION TECHNIQUESINSPECTION TECHNIQUESCRACKS GREW WITH TIMECRACKS GREW WITH TIMECOLD WEATHER CONTRIBUTED TO BRITTLE COLD WEATHER CONTRIBUTED TO BRITTLE FRACTUREFRACTUREINSPECTION OF GIRDERS IN SERVICE PREVENTED INSPECTION OF GIRDERS IN SERVICE PREVENTED BY WALLSBY WALLSTHE STEEL USED DID NOT MEET MATERIAL THE STEEL USED DID NOT MEET MATERIAL REQUIREMENTS FOR TOUGHNESS NEEDED FOR REQUIREMENTS FOR TOUGHNESS NEEDED FOR THE TYPE OF CONSTRUCTION. NOT TESTED FOR THE TYPE OF CONSTRUCTION. NOT TESTED FOR TOUGHNESS.TOUGHNESS.

TOUGHNESSTOUGHNESS

TOUGHNESSTOUGHNESS

IMPACTSIMPACTS

LED TO MORE TESTING REQUIREMENTS LED TO MORE TESTING REQUIREMENTS FOR MATERIALS WHEN USING NEW FOR MATERIALS WHEN USING NEW TECHNIQUESTECHNIQUESPOINTED OUT NEED FOR HIGHER LEVEL OF POINTED OUT NEED FOR HIGHER LEVEL OF INSPECTION AND TESTING WHEN USING INSPECTION AND TESTING WHEN USING NEW APPROACHESNEW APPROACHESLED TO REQUIREMENTS FOR BRIDGE LED TO REQUIREMENTS FOR BRIDGE COMPONENTS BEING ACCESSIBLE TO COMPONENTS BEING ACCESSIBLE TO INSPECTION.INSPECTION.

POINT PLEASANT POINT PLEASANT -- 19671967

SUSPENSION SUSPENSION BRIDGE BUILT IN BRIDGE BUILT IN 192619261460 FEET LONG1460 FEET LONGUSED EYEUSED EYE--BAR BAR CHAINS INSTEAD CHAINS INSTEAD OF TYPICAL WIRE OF TYPICAL WIRE STRAND FOR STRAND FOR CABLESCABLES

FAILUREFAILURE

COLLAPSED IN RUSH HOUR TRAFFICCOLLAPSED IN RUSH HOUR TRAFFIC46 KILLED46 KILLED

CAUSESCAUSES

ONE EYEBAR CRACKED AND BROKEONE EYEBAR CRACKED AND BROKEFATIGUE DUE TO HIGHFATIGUE DUE TO HIGH--STRENGTH STRENGTH STEEL WHICH IS MORE BRITTLESTEEL WHICH IS MORE BRITTLECORROSION ACCELERATED BY CORROSION ACCELERATED BY STRESSSTRESSINSPECTIONS NOT DONE (LAST INSPECTIONS NOT DONE (LAST BEFORE FAILURE WAS IN 1951)BEFORE FAILURE WAS IN 1951)

IMPACTSIMPACTS

LED TO A NATIONWIDE BRIDGE LED TO A NATIONWIDE BRIDGE INSPECTION PROGRAM MANDATED INSPECTION PROGRAM MANDATED BY FEDERAL HIGHWAY DEPARTMENTBY FEDERAL HIGHWAY DEPARTMENT

MIANUS IMIANUS I--95 95 -- 19831983

BRIDGE BUILT IN 1958BRIDGE BUILT IN 1958CONVENTIONAL DESIGNCONVENTIONAL DESIGNGIRDERS USED PIN HANGAR GIRDERS USED PIN HANGAR CONNECTIONCONNECTION

FAILUREFAILURE

A 100A 100--FOOT SPAN FOOT SPAN OF ONE LANE OF ONE LANE COLLAPSED COLLAPSED KILLING 3KILLING 3CAUSED MAJOR CAUSED MAJOR TRAFFIC TRAFFIC DISRUPTIONDISRUPTION

CAUSECAUSE

CORROSION OF PIN HANGARS CORROSION OF PIN HANGARS POOR MAINTENANCEPOOR MAINTENANCE–– LACK OF CLEANING ALLOWED LACK OF CLEANING ALLOWED

CORROSIONCORROSIONINADEQUATE INSPECTIONINADEQUATE INSPECTION–– PROBLEMS COULD HAVE BEEN SEENPROBLEMS COULD HAVE BEEN SEEN–– LACK OF STAFF AND MONEYLACK OF STAFF AND MONEYDEFICIENT DESIGN CLAIMED, BUT DEFICIENT DESIGN CLAIMED, BUT NOT PROVENNOT PROVEN

IMPACTSIMPACTS

HIGHER PRIORITY GIVEN TO HIGHER PRIORITY GIVEN TO INSPECTION AND MAINTENANCEINSPECTION AND MAINTENANCEINSPECTIONS OF OTHER SIMILAR INSPECTIONS OF OTHER SIMILAR BRIDGES FOUND SIMILAR PROBLEMS.BRIDGES FOUND SIMILAR PROBLEMS.STRENGTHENING DONE ON OTHER STRENGTHENING DONE ON OTHER BRIDGESBRIDGES

SCHOHARIE BRIDGE SCHOHARIE BRIDGE -- 19871987

CONVENTIONAL CONCRETE DECK CONVENTIONAL CONCRETE DECK AND STEEL GIRDER BRIDGE BUILT IN AND STEEL GIRDER BRIDGE BUILT IN 19521952FIVE SPANS CARRIED BY FOUR FIVE SPANS CARRIED BY FOUR PIERS, TWO IN CREEK BEDPIERS, TWO IN CREEK BEDWELL MAINTAINEDWELL MAINTAINEDINSPECTED IN YEAR BEFORE INSPECTED IN YEAR BEFORE COLLAPSECOLLAPSE

FAILUREFAILUREFAILED DURING FAILED DURING HEAVY RAINHEAVY RAIN

CENTER SPANS CENTER SPANS COLLAPSED INTO COLLAPSED INTO CREEK FIRST CREEK FIRST FOLLOWED BY END FOLLOWED BY END SPANSSPANS

10 PEOPLE KILLED 10 PEOPLE KILLED

CAUSECAUSE

NOT A STRUCTURAL FAILURENOT A STRUCTURAL FAILURERIVER BED SCOUR REMOVED SUPPORT RIVER BED SCOUR REMOVED SUPPORT FOR THE FOOTINGS SUPPORTING THE FOR THE FOOTINGS SUPPORTING THE PIERSPIERSUPSTREAM FLOOD CONTROL DAM UPSTREAM FLOOD CONTROL DAM RELEASED WATER IN ADDITION TO RAINRELEASED WATER IN ADDITION TO RAINORIGINAL FILES HAD REPORT WARNING OF ORIGINAL FILES HAD REPORT WARNING OF SCOUR POTENTIALSCOUR POTENTIALINSPECTIONS DID NOT CHECK FOR SCOUR INSPECTIONS DID NOT CHECK FOR SCOUR

IMPACTSIMPACTS

ALTHOUGH SCOUR KNOWN AS A ALTHOUGH SCOUR KNOWN AS A RISK, ITS IMPORTANCE HIGHLIGHTED RISK, ITS IMPORTANCE HIGHLIGHTED BY THIS FAILURE.BY THIS FAILURE.LED TO REQUIREMENT OF SCOUR LED TO REQUIREMENT OF SCOUR ANALYSIS FOR ALL BRIDGES ANALYSIS FOR ALL BRIDGES CROSSING CREEKS.CROSSING CREEKS.LED TO INCLUDING UNDERWATER LED TO INCLUDING UNDERWATER EXAMINATION IN INSPECTIONSEXAMINATION IN INSPECTIONS

SUMMARY FOR BRIDGESSUMMARY FOR BRIDGES

MAJOR CAUSESMAJOR CAUSES–– DESIGN ERRORSDESIGN ERRORS–– PUSHING LIMITS WITHOUT ENOUGH PUSHING LIMITS WITHOUT ENOUGH

STUDY OR TESTINGSTUDY OR TESTING–– CORROSION OF MATERIALSCORROSION OF MATERIALS–– POOR MAINTENANCEPOOR MAINTENANCE–– INTERACTION WITH NATURE (SCOUR)INTERACTION WITH NATURE (SCOUR)–– POST CONSTRUCTION ACCIDENTS NOT A POST CONSTRUCTION ACCIDENTS NOT A

TECHNOLOGY FAILURETECHNOLOGY FAILURE

BUILDING FAILURESBUILDING FAILURES

HISTORICAL FAILURES HISTORICAL FAILURES -- TAPETAPEBOSTON MOLASSES TANK BOSTON MOLASSES TANK –– 19191919SKYLINE PLAZA SKYLINE PLAZA –– 19731973HARTFORD CIVIC CENTER HARTFORD CIVIC CENTER --19781978KEMPER ARENA KEMPER ARENA –– 19791979HYATT REGENCY WALKWAYS HYATT REGENCY WALKWAYS –– 19811981LL’’AMBIANCE PLAZA AMBIANCE PLAZA -- 19871987

BOSTON MOLASSES TANK BOSTON MOLASSES TANK --19191919

TANK WAS 90TANK WAS 90’’ DIAMETER AND 50DIAMETER AND 50’’HIGHHIGHMADE OF STEEL PLATES RIVETED MADE OF STEEL PLATES RIVETED TOGETHER SUPPORTED ON TOGETHER SUPPORTED ON CONCRETE FLOORCONCRETE FLOORCOMPLETED IN 1916 AND TESTED BY COMPLETED IN 1916 AND TESTED BY RUNNING 6RUNNING 6”” OF WATER INTO ITOF WATER INTO ITNEVER FILLED TO MAXIMUM BEFORE NEVER FILLED TO MAXIMUM BEFORE FAILUREFAILURE

FAILUREFAILURE

TANK BURST OPEN RELEASING TANK BURST OPEN RELEASING FLOOD OF MOLASSES 2FLOOD OF MOLASSES 2--STORIES STORIES HIGH AND 160 FEET WIDE.HIGH AND 160 FEET WIDE.DESTROYED BUILDINGS, ELEVATED DESTROYED BUILDINGS, ELEVATED RAIL LINESRAIL LINESKILLED 21, INJURED >150KILLED 21, INJURED >150TOOK MONTHS TO CLEAN UP TOOK MONTHS TO CLEAN UP MOLASSESMOLASSES

MOLASSES FLOODMOLASSES FLOOD

CAUSECAUSESTUDY FOUND STEEL PLATES THINNER STUDY FOUND STEEL PLATES THINNER THAN CALLED FOR ON DESIGN PLANS THAN CALLED FOR ON DESIGN PLANS SUBMITTED.SUBMITTED.RIVETED JOINT IN SECOND RING PLACED RIVETED JOINT IN SECOND RING PLACED ABOVE A CUTOUT IN FIRST RING, ABOVE A CUTOUT IN FIRST RING, INCREASING STRESSINCREASING STRESSMANHOLE CUTOUT NOT REINFORCEDMANHOLE CUTOUT NOT REINFORCEDIMPROPER DESIGN, NO CHECK OF IMPROPER DESIGN, NO CHECK OF CALCULATIONS BY ENGINEERCALCULATIONS BY ENGINEERPOOR CONSTRUCTIONPOOR CONSTRUCTION

IMPACTSIMPACTS

CALCULATIONS REQUIRED TO BE CALCULATIONS REQUIRED TO BE SUBMITTED BY BOSTONSUBMITTED BY BOSTONDRAWINGS SUBMITTED TO BE SIGNED BY DRAWINGS SUBMITTED TO BE SIGNED BY ENGINEERENGINEERINFLUENCED ADOPTION OF ENGINEERING INFLUENCED ADOPTION OF ENGINEERING LICENSING LAWS AND REQUIREMENTS FOR LICENSING LAWS AND REQUIREMENTS FOR SUBMITTING DRAWINGS STAMPED AND SUBMITTING DRAWINGS STAMPED AND SIGNED BY REGISTERED EINGINEERSIGNED BY REGISTERED EINGINEER

SKYLINE PLAZA SKYLINE PLAZA -- 19731973CASTCAST--ININ--PLACE CONCRETE APARTMENT BUILDING PLACE CONCRETE APARTMENT BUILDING COLLAPSED DURING CONSTRUCTIONCOLLAPSED DURING CONSTRUCTIONDESIGN COMMON, AND CONSTRUCTION METHOD DESIGN COMMON, AND CONSTRUCTION METHOD COMMONCOMMONEXAMPLE OF THIS TYPE OF CONSTRUCTION CAN EXAMPLE OF THIS TYPE OF CONSTRUCTION CAN BE SEEN DOWNTOWN TODAYBE SEEN DOWNTOWN TODAYONE OF SEVERAL BUILDINGS PLANNED; OTHERS ONE OF SEVERAL BUILDINGS PLANNED; OTHERS COMPLETED OKCOMPLETED OKPLACING CONCRETE FOR 24PLACING CONCRETE FOR 24thth FLOOR WHEN FLOOR WHEN FAILEDFAILED

POST FAILURE PHOTO

NOTE SLAB SECTIONS

HANGING DOWN

FAILUREFAILURECONSTRUCTION SEQUENCE IS PLACE ONE FLOOR CONSTRUCTION SEQUENCE IS PLACE ONE FLOOR THEN COLUMNS. FORM FOR SECOND FLOOR. THEN COLUMNS. FORM FOR SECOND FLOOR. USE METAL OR WOOD SUPPORT FOR SECOND USE METAL OR WOOD SUPPORT FOR SECOND FLOOR TIL CONCRETE STRONG ENOUGH.FLOOR TIL CONCRETE STRONG ENOUGH.2424THTH FLOOR BEGAN SAGGING WHILE PLACING FLOOR BEGAN SAGGING WHILE PLACING CONCRETE, AS DID 23CONCRETE, AS DID 23RDRD FLOOR WHICH WAS ONLY FLOOR WHICH WAS ONLY 44--DAYS OLD.DAYS OLD.COLLAPSE ALLOWED WET CONCRETE TO IMPACT COLLAPSE ALLOWED WET CONCRETE TO IMPACT FLOOR BELOW, BREAKING THROUGH AND FLOOR BELOW, BREAKING THROUGH AND SUCCESSIVELY THROUGH THE FLOORS BELOW.SUCCESSIVELY THROUGH THE FLOORS BELOW.14 KILLED AND 34 INJURED.14 KILLED AND 34 INJURED.

CAUSECAUSE

PREMATURE REMOVAL OF SHORING PREMATURE REMOVAL OF SHORING BELOW THE 23BELOW THE 23RDRD FLOORFLOORPLACING 24PLACING 24THTH FLOOR TOO SOON, FLOOR TOO SOON, BEFORE 23BEFORE 23RDRD FLOOR CONCRETE HAD FLOOR CONCRETE HAD REACHED ENOUGH STRENGTHREACHED ENOUGH STRENGTHSHORING SYSTEM POORLY SHORING SYSTEM POORLY DESIGNED AND INSTALLEDDESIGNED AND INSTALLEDSPEEDING UP CONSTRUCTIONSPEEDING UP CONSTRUCTION

IMPACTSIMPACTS

ALTHOUGH POINTED OUT SOME BASIC ALTHOUGH POINTED OUT SOME BASIC FLAWS IN CONSTRUCTION PROCESS, FEW FLAWS IN CONSTRUCTION PROCESS, FEW CHANGES HAVE BEEN MADE.CHANGES HAVE BEEN MADE.CONTRACTOR IS RESPONSIBLE FOR CONTRACTOR IS RESPONSIBLE FOR SHORING DESIGN AND INSTALLATION; NO SHORING DESIGN AND INSTALLATION; NO INDEPENDENT INSPECTIONS REQUIREDINDEPENDENT INSPECTIONS REQUIREDCONSTRUCTION COLLAPSES STILL OCCUR, CONSTRUCTION COLLAPSES STILL OCCUR, MANY FROM SAME CAUSESMANY FROM SAME CAUSES

HARTFORD CIVIC CENTER HARTFORD CIVIC CENTER --19781978

BUILT IN 1972BUILT IN 1972ROOF WAS EARLY EXAMPLE OF A ROOF WAS EARLY EXAMPLE OF A SPACE TRUSS AND CONSIDERED AT SPACE TRUSS AND CONSIDERED AT LEADING EDGE OF DESIGNLEADING EDGE OF DESIGNROOF WAS 21 FEET DEEP AND 300 BY ROOF WAS 21 FEET DEEP AND 300 BY 360 FEET360 FEETEARLY USE OF COMPUTEREARLY USE OF COMPUTER--AIDED AIDED DESIGNDESIGN

FAILUREFAILURE

COLLAPSE OF COLLAPSE OF ROOF UNDER ROOF UNDER SNOW LOADSNOW LOADFORTUNATELY NO FORTUNATELY NO ONE KILLEDONE KILLEDGO TO THE TAPEGO TO THE TAPE

IMPACTSIMPACTSSHOOK PUBLIC CONFIDENCE IN SPACE SHOOK PUBLIC CONFIDENCE IN SPACE TRUSS ROOFSTRUSS ROOFSPRESIDENT FORD ORDERED WATER LOAD PRESIDENT FORD ORDERED WATER LOAD TESTING FOR SUCH A ROOF OVER TESTING FOR SUCH A ROOF OVER MUSEUM IN MICHIGANMUSEUM IN MICHIGANTEMPERED ENGINEERS AND ARCHITECTS TEMPERED ENGINEERS AND ARCHITECTS RELIANCE ON COMPUTER MODELS TO CUT RELIANCE ON COMPUTER MODELS TO CUT DOWN STRUCTURE TO BARE MINIMUM DOWN STRUCTURE TO BARE MINIMUM LEAVING NO REDUNDANCY OR MARGIN LEAVING NO REDUNDANCY OR MARGIN FOR ERRORFOR ERROR

KEMPER ARENA KEMPER ARENA -- 19791979

BUILT IN 1974 AND WON AWARDS FOR BUILT IN 1974 AND WON AWARDS FOR DESIGNDESIGNROOF WAS 324ROOF WAS 324’’ BY 310BY 310’’ SYSTEM OF SYSTEM OF SPACE TRUSSES HUNG FROM THREE SPACE TRUSSES HUNG FROM THREE HUGE SPACE FRAME TRUSSESHUGE SPACE FRAME TRUSSESCONNECTIONS WERE BY HIGHCONNECTIONS WERE BY HIGH--STRENGTH BOLTSSTRENGTH BOLTSROLL TAPEROLL TAPE

FAILUREFAILURE

FAILED DURING FAILED DURING RAINSTORM AND RAINSTORM AND AFTER EVENTSAFTER EVENTSMOST OF ROOF MOST OF ROOF STRUCTURE FELL STRUCTURE FELL DOWN; SPACE DOWN; SPACE FRAME SUPPORTS FRAME SUPPORTS NOT DAMAGED.NOT DAMAGED.NO ONE KILLED OR NO ONE KILLED OR INJUREDINJURED

CAUSECAUSE

STUDY POINTED TO FAILURE OF THE HIGHSTUDY POINTED TO FAILURE OF THE HIGH--STRENGTH BOLTS. STRENGTH BOLTS. BOLTS WEAKENED BY FATIGUEBOLTS WEAKENED BY FATIGUEBOLTS MAY NOT HAVE BEEN CORRECTLY BOLTS MAY NOT HAVE BEEN CORRECTLY TIGHTENEDTIGHTENEDEXCESSIVE WATER ACCUMULATED ON EXCESSIVE WATER ACCUMULATED ON ROOF DUE TO LACK OF SUFFICIENT ROOF DUE TO LACK OF SUFFICIENT DRAINAGE AND HIGH WINDS CAUSING DRAINAGE AND HIGH WINDS CAUSING POOLINGPOOLING

IMPACTSIMPACTSNEW ROOF HUNG FROM ORIGINAL SPACE NEW ROOF HUNG FROM ORIGINAL SPACE FRAME TRUSSES FRAME TRUSSES USED PIN CONNECTIONS NOT BOLTSUSED PIN CONNECTIONS NOT BOLTSDRAINAGE IMPROVED AND ROOF SLOPE DRAINAGE IMPROVED AND ROOF SLOPE INCREASEDINCREASEDLED TO INSPECTIONS OF STRUCTURES LED TO INSPECTIONS OF STRUCTURES WITH THE HIGHWITH THE HIGH--STRENGTH BOLTS TO SEE STRENGTH BOLTS TO SEE IF PROPERLY TIGHTENEDIF PROPERLY TIGHTENEDLED TO GREATER DESIGN CONCERN AND LED TO GREATER DESIGN CONCERN AND ATTENTION TO HIGHATTENTION TO HIGH--STRENGTH BOLTSSTRENGTH BOLTS

HYATT REGENCY HOTEL HYATT REGENCY HOTEL WALKWAYS WALKWAYS -- 19811981

HOTEL ATRIUM LOBBY CROSSED BY HOTEL ATRIUM LOBBY CROSSED BY THREE HANGING WALKWAYS THREE HANGING WALKWAYS CONNECTED TO BALCONIESCONNECTED TO BALCONIESCOLLAPSE KILLED 114 AND INJURED COLLAPSE KILLED 114 AND INJURED ~200~200ROLL TAPEROLL TAPE

HYATT DETAILSHYATT DETAILS

CAUSECAUSEHANGAR CONNECTION NOT DESIGNED BY HANGAR CONNECTION NOT DESIGNED BY DESIGNER, BUT BY SHOP FABRICATORDESIGNER, BUT BY SHOP FABRICATORREDESIGN NOT CHECKED BY DESIGNERREDESIGN NOT CHECKED BY DESIGNERDESIGN BUILT WAS INADEQUATE FOR DESIGN BUILT WAS INADEQUATE FOR LOADS APPLIEDLOADS APPLIEDONE WALKWAY COLLAPSE LED TO ONE WALKWAY COLLAPSE LED TO OVERLOADING OF OTHERSOVERLOADING OF OTHERSMATERIALS AND CONSTRUCTION WERE MATERIALS AND CONSTRUCTION WERE NOT AT FAULTNOT AT FAULT

IMPACTSIMPACTS

TWO DESIGNERS LOST LICENSESTWO DESIGNERS LOST LICENSESLED TO BETTER DESIGN AND REVIEW LED TO BETTER DESIGN AND REVIEW OF CONNECTIONSOF CONNECTIONSPROBLEMS STILL EXIST WITH PROBLEMS STILL EXIST WITH RESPONSIBILITY FOR DESIGN OF RESPONSIBILITY FOR DESIGN OF STEEL CONSTRUCTION. STEEL CONSTRUCTION. STRUCTURAL ENGINEER STRUCTURAL ENGINEER vsvsFABRICATORFABRICATOR

LL’’AMBIANCE PLAZA AMBIANCE PLAZA -- 19871987

ONE OF TOO MANY EXAMPLES OF ONE OF TOO MANY EXAMPLES OF CONSTRUCTION FAILURECONSTRUCTION FAILUREAPARTMENT BUILDING WITH APARTMENT BUILDING WITH CONCRETE CONSTRUCTION USING CONCRETE CONSTRUCTION USING ““LIFT SLABLIFT SLAB”” METHODMETHODPLANNED FOR 13 STORIES; FAILED PLANNED FOR 13 STORIES; FAILED WHILE ABOUT 50% DONEWHILE ABOUT 50% DONE

FAILUREFAILURELIFT SLAB METHOD CALLS FOR POURING LIFT SLAB METHOD CALLS FOR POURING CONCRETE SLABS ON TOP OF EACH CONCRETE SLABS ON TOP OF EACH OTHER ON THE GROUND THEN POSTOTHER ON THE GROUND THEN POST--TENSIONING AND LIFTING UP ALONG TENSIONING AND LIFTING UP ALONG COLUMNS TO FINAL POSITION.COLUMNS TO FINAL POSITION.COLLAPSE OCCURRED WITH SLABS AT THE COLLAPSE OCCURRED WITH SLABS AT THE 99THTH FLOOR LEVEL.FLOOR LEVEL.PROGRESSIVE FAILURE AS FLOORS FELL.PROGRESSIVE FAILURE AS FLOORS FELL.28 KILLED AND 16 INJURED28 KILLED AND 16 INJURED

CAUSECAUSE

CONNECTION OF A JACK TO THE SLAB CONNECTION OF A JACK TO THE SLAB FAILED AND ALLOWED A BOLT TO FAILED AND ALLOWED A BOLT TO SLAM INTO COLUMNSLAM INTO COLUMNSLAB BEGAN TO DEFLECT AND SLAB BEGAN TO DEFLECT AND CAUSED PROGRESSIVE FAILURESCAUSED PROGRESSIVE FAILURESINADEQUATE DESIGN OF LIFTING INADEQUATE DESIGN OF LIFTING COMPONENTSCOMPONENTSFORMAL CAUSE NEVER AGREED FORMAL CAUSE NEVER AGREED UPON UPON

IMPACTSIMPACTS

SOME CHANGES IN CONSTRUCTION SOME CHANGES IN CONSTRUCTION PROCEDURES MADEPROCEDURES MADEOSHA MANDATED ADHERENCE TO OSHA MANDATED ADHERENCE TO HIGHER SAFETY FACTORS FOR LIFT HIGHER SAFETY FACTORS FOR LIFT SLAB PROJECTSSLAB PROJECTSNEW STANDARDS WRITTEN FOR NEW STANDARDS WRITTEN FOR EVALUATING STRUCTURAL LOADS EVALUATING STRUCTURAL LOADS DURING CONSTRUCTIONDURING CONSTRUCTION

BUILDINGS BUILDINGS -- SUMMARYSUMMARY

EARLY 1900EARLY 1900’’S FAILURES OFTEN DUE TO S FAILURES OFTEN DUE TO LACK OF DESIGN KNOWLEDGE OR LACK OF DESIGN KNOWLEDGE OR UNDERSTANDING OF MATERIAL UNDERSTANDING OF MATERIAL BEHAVIOURBEHAVIOURLATER, STILL SOME MATERIALS ISSUESLATER, STILL SOME MATERIALS ISSUESCONNECTIONS OFTEN A BIG PROBLEMCONNECTIONS OFTEN A BIG PROBLEMCONSTRUCTION IMPLEMENTATION A CONSTRUCTION IMPLEMENTATION A MAJOR CONTRIBUTOR TO MANY RECENT MAJOR CONTRIBUTOR TO MANY RECENT FAILURESFAILURES

CURRENT PRACTICECURRENT PRACTICE

STRICT CODES FOR MATERIALSSTRICT CODES FOR MATERIALS–– AISC, ACI, ASTMAISC, ACI, ASTMREVIEWS AND PERMITTING REVIEWS AND PERMITTING PROCESSESPROCESSES–– FEDERAL HIGHWAYSFEDERAL HIGHWAYS–– STATE CONSTRUCTIONSTATE CONSTRUCTION–– LOCAL BUILDING DEPARTMENTSLOCAL BUILDING DEPARTMENTS

CURRENT PRACTICESCURRENT PRACTICES

BUILDING CODES REQUIRING MORE BUILDING CODES REQUIRING MORE INSPECTIONINSPECTION–– NEW NC CODE CALLS FOR NEW NC CODE CALLS FOR ““SPECIAL SPECIAL

INSPECTIONSINSPECTIONS””STILL PROBLEMS IN CONSTRUCTION STILL PROBLEMS IN CONSTRUCTION IMPLEMENTATION OF DESIGNSIMPLEMENTATION OF DESIGNS

WHEN TECHNOLOGY WHEN TECHNOLOGY SUCCEEDSSUCCEEDS

MOVING THE CAPEMOVING THE CAPEHATTERAS LIGHTSTATIONHATTERAS LIGHTSTATION