PETRONAS TWIN TOWER, KUALA LUMPUR, MALAYSIA

By- Nawal Kishor DwivediM.Tech Structural Engineering , MNIT Jaipur

GENERAL FACTS

6RD TALLEST BUILDING IN THE WORLD , MARCH 2014

TALLEST BUILDING IN WORLD FROM 1998 TO 2004

PRECEEDED BY INTERNATIONAL COMMERCE CENTER , HONG KONG ,CHINA

SURPASSED BY NANJING GREENLAND FINANCIAL COMPLEX ,CHINA

LOCATION : KLLC , JALAN AMPANG , KUALA LUMPUR , MALAYSIA

TYPE : COMMERCIAL , TOURIST ATTRACTION

CONSTRUCTON STARTED ON 1ST MARCH 1993 AND COMPLETED ON 1ST MARCH 1996

COST : US$ 1.6 BILLION

OWNER : KLLC HOLDINGS

NUMBER OF STOREY: 88 (+ 4 BASEMENT FLOORS)

TOTAL HEIGHT : 451.9 m (Architectural ) 378.6 m ( Roof ) LIFTS/ELEVATORS : 78

FLOOR AREA : 395000 m sq

MATERIAL : CONCRETE , STEEL

ARCHITECT : CESAR PELLI

STRUCTURAL ENGINEER : THORNTON THORMASETI

CONTRACTORS : TOWER 1 : HAZAMA CORPORATION TOWER 2 : SAMSUNG ENGG.& CO.

PROJECT DATA

EACH TOWER : 88 STOREYS

TOWER 1 :PETRONAS HEAD QUARTERS

TOWER 2 :LOCAL AND INTERNATIONAL PRIVATE

TENANTS, KLCC HOLDINGS

SMALLER CIRCULAR BUSTLE OR ANEXX ADDED

TO EACH TOWER RISING 44 STOREY

TOWERS CONNECTED BY SKY BRIDGE AT 41ST &

42ND STOREY

SKY BRIDGE: CENTRE-LINE SPAN: 58.44 METRES; WIDTH, 5.29 METRES HEIGHT, 9.45 METRES

FINISHED CEILING HEIGHT: 2.65 METRES HEIGHT OF PINNACLES: 73.5 - 75 METRES FLOOR AREA VARRIES AS TOWER ACCENDS CENTRAL CORE GROSS AREA :510 m sq approx

FACILITIES : 3 LEVEL CONCERT HALL 6 STOREY RETAIL AND ENTERTAINMENT PARK PETROLEUM RESEARCH CENTRE 4 STOREY BASEMENT PARKING etc.

FOUNDATION

EARLY EXCAVATION PROBLEM : LIMESTONE BEDROCK

300000 METRIC TON WEIGHT OF EACH TOWER

TO BE SPREAD ON MAT FOUNDATION

PRESSURE EXERTED BY EACH TOWER : 1140 K-Pa (more than twice

bearing cap. of soil available)

ALSO BED ROCK WAS SLOPING – MAY LEAD TO FAILURE

CONSTRUCTION SITE SHIFTED 60 m AWAY

FINALLY RESTED ON CONCRETE MAT ANCHORED WITH

CONCRETE FRICTION PILES

4.5 M THICK RAFT SUPPORTED ON 45-105 M RECTANGULAR PILES

LONGER PILES WHERE DEEP BED ROCK- TO AVOID

DIFFERENTIAL SETTLEMENT

M45 CONCRETE USED FOR PILES

13200 cu m OF M60 CONCRETE USED IN RAFT

CHILLED WATER USED- MINIMIZE DIFFRENTIAL

TEMPERAURE

CENTRAL CORE CENTRAL CORE IN EACH TOWER ACCOMMODATE – LIFTS, EXIT STAIRS, MECHANICAL SERVICES TWO SOLID WALLS RUNNING N-S AND E-W- WEB CANTILEVER BEAMS PROJECTING-MAKES IT STIFF TAKES MORE THAN HALF THE TWISTING MOMENT HIGHLY REINFORCED THICK CORNER WALLS- RESIST WIND CORE VARRIES FROM 22 sq m TO 19 X 22 m IN FOUR STEPS OUTER WALLS 750 TO 350 mm INNER WALLS COSTANT 350 mm- TO AVOID COMPLICATION WITH LIFT SHAFT CONCRETE GRADE DROPS FROM 80 -40 Mpa AS IT ACCENTS

FLOOR PLAN

CORE WALL LAYOUT

COLUMNS

COLUMNS CAST IN REUSABLE STEEL FORMS FINELY FINISHED COLUMNS OPEN TO VIEW AT MOST OF THE FLOORS 16 TOWER COLUMN- VARRY ALONG HIGHT IN DIA. 2.4 m TO 1.4 m DIA CONCRETE VARRIED FROM M80 TO M30 IN 3 STEPS 12 BUSTLE COLUMS – 1.4m TO 1m SETBACKS AT 60, 73 AND 82 SLOPING COLUMS OVER 3 STOREY HEIGHTS ABOVE FLOOR 84 – HIGH SLOPE – STEEL COLUMN USED TO AVOID COMPLICATION

COLUMN SIZE AND COLUMN GRADE

SLOPING COLUMN

BEAMS TAPERED RING BEAMS ALL AROUND DEPTH 1.15 m AT COLUMN TO 725 mm AT FLAT ZONE SPAN VARIATION DUE TO COLUMN CHANGES AND SET BACKS BEAM GRADE MATCHES COLUMN GRADE TO SIMPLIFY PUMPING

OUTRIGGERS E-W OUTRIGGER LINK CORE AND COLUMNS AT FLOOR 38-40 3 LEVEL BEAMS LINKED BY MID SPAN POSTS – HELP RESIST WIND EFFECT

SKY BRIDGE DOUBLE DECK BRIDGE SPANNING 58.4 m CONNECTS TWO TOWER AT SKYLOBBY ELEVATOR TRANSFER STATION ON FLOOR 41 AND 42 EASY CIRCULATION B/W UPPER TOWER FLOORS MINIMIZE LIFT USAGE REDUCES FIRE EXIT REQUIREMENT GREAT HEIGHT AND SPAN REQUIRES STEEL FOR LIGHT WEIGHT AND EASY CONST. TWO HINGED ARCH SUPPORTS THE SPAN SELF CENTRING ACTION FROM RESTRAIN AT ARCH CROWN AND SPHERICAL PIN AT SUPPORTS

PINNACLE EACH TOWER CROWNED BY- 73 m TAPERING TOP ACCOMMODATES – BUILDING MAINTENANCE MACHINE , AVIATION LIGHTING AND LIGHTING PROTECTION DUE TO STEEP SLOPING COLUMN CONCRETE CONSTRUCTION IMPARACTICAL STEEL USED THROUGHOUT LOWER PINNACLE- 8 STRUCTURAL STEEL FRAMES UPPER PINNACLE – SINGLE MAST OF TAPERING CIRCULAR CROSS SECTION

PINNACLE ELEVATION

DYNAMIC STUDIES

CROSS WIND EFFECTS ON STRUCTURE AND USER COMFORT ANALYTICAL MODELLING : 3D MODELLING USING SAP90 INCLUDING PERIMETER BEAMS, COLUMNS, CENTRAL COLUMN REPRESENTING CORE & OUTRIGGER SYSTEM COLUMN GROSS CROSS SECTION PROPERTIES USED- COMPRESSIVE STRESSES DOMINANT ELASTIC MODULI ‘E’ VALUES VARIED WITH STRENGTH ACCORDING TO ACI318 ‘E’ VALUES NOT REDUCED FOR CREEP- SHORT TERM WIND LOADING BEAMS ASSUMED TO BE ‘CRACKED’- AVG. STIFFNESS I/2

WIND MODELLING DESIGN WIND 35 m/s ASSUMED AT 10m ELEVATION RETURN PERIOD 50 YEARS FORCING FUNCTION DETERMINED USING IT ANALYSIS FOR DYNAMIC FORCE AT 1-2% DAMPING RESULTS REVEALED 2% DAMPING REDUCES BASE SHEAR VALUES WELL BELOW LIMITS NO REQIREMENT OF TUNED DAMPERS

SIMILAR DYNAMIC MODELLING DONE FOR SKY BRIDGE,PINNACLE SKY BRIDGE REQIRED TUNED MASS DAMPERS-3 EACH LEG

CONCLUSION

MIXED CONSTRUCTION FOR COST AND USABILITY BENEFIT USE OF HPC – REASONABLE SECTIONS, LOW COST , MORE SPACE CONCRETE CONSTRUCTION- SIMPLE EQUIPMENTS LESS SKILL , EASY CONNECTION CONCRETE – BENEFITS WIND BEHAVIOUR –INHERENT STIFFNESS AND DAMPING STEEL – FAST AND FLEXIBLE ERECTION- PEMITS LAST MINUTE CHANGE WIND EXCITATION –BENIFICIAL FOR–SIZE 55mm to .3m