PETRONAS TWIN TOWER KUALA LUMPUR MALAYSIA By Nawal

PETRONAS TWIN TOWER, KUALA LUMPUR, MALAYSIA By- Nawal Kishor Dwivedi M. Tech Structural Engineering , MNIT Jaipur

GENERAL FACTS Ø 6 RD TALLEST BUILDING IN THE WORLD , MARCH 2014 Ø TALLEST BUILDING IN WORLD FROM 1998 TO 2004 Ø PRECEEDED BY INTERNATIONAL COMMERCE CENTER , HONG KONG , CHINA ØSURPASSED BY NANJING GREENLAND FINANCIAL COMPLEX , CHINA ØLOCATION : KLLC , JALAN AMPANG , KUALA LUMPUR , MALAYSIA

Ø TYPE : COMMERCIAL , TOURIST ATTRACTION Ø CONSTRUCTON STARTED ON 1 ST MARCH 1993 AND COMPLETED ON 1 ST MARCH 1996 Ø COST : US$ 1. 6 BILLION Ø OWNER : KLLC HOLDINGS ØNUMBER OF STOREY: 88 (+ 4 BASEMENT FLOORS) Ø TOTAL HEIGHT : 451. 9 m (Architectural ) 378. 6 m ( Roof ) Ø LIFTS/ELEVATORS : 78

Ø FLOOR AREA : 395000 m sq Ø MATERIAL : CONCRETE , STEEL Ø ARCHITECT : CESAR PELLI Ø STRUCTURAL ENGINEER : THORNTON THORMASETI Ø CONTRACTORS : TOWER 1 : HAZAMA CORPORATION TOWER 2 : SAMSUNG ENGG. & CO.

PROJECT DATA Ø EACH TOWER : 88 STOREYS Ø TOWER 1 : PETRONAS HEAD QUARTERS ØTOWER 2 : LOCAL AND INTERNATIONAL PRIVATE TENANTS, KLCC HOLDINGS Ø SMALLER CIRCULAR BUSTLE OR ANEXX ADDED TO EACH TOWER RISING 44 STOREY Ø TOWERS CONNECTED BY SKY BRIDGE AT 41 ST & 42 ND STOREY

Ø SKY BRIDGE: CENTRE-LINE SPAN: 58. 44 METRES; WIDTH, 5. 29 METRES HEIGHT, 9. 45 METRES ØFINISHED CEILING HEIGHT: 2. 65 METRES Ø HEIGHT OF PINNACLES: 73. 5 - 75 METRES Ø FLOOR AREA VARRIES AS TOWER ACCENDS Ø CENTRAL CORE GROSS AREA : 510 m sq approx Ø FACILITIES : 3 LEVEL CONCERT HALL 6 STOREY RETAIL AND ENTERTAINMENT PARK PETROLEUM RESEARCH CENTRE 4 STOREY BASEMENT PARKING etc.

FOUNDATION Ø EARLY EXCAVATION PROBLEM : LIMESTONE BEDROCK Ø 300000 METRIC TON WEIGHT OF EACH TOWER Ø TO BE SPREAD ON MAT FOUNDATION Ø PRESSURE EXERTED BY EACH TOWER : 1140 K-Pa (more than twice bearing cap. of soil available) Ø ALSO BED ROCK WAS SLOPING – MAY LEAD TO FAILURE Ø CONSTRUCTION SITE SHIFTED 60 m AWAY Ø FINALLY RESTED ON CONCRETE MAT ANCHORED WITH CONCRETE FRICTION PILES Ø 4. 5 M THICK RAFT SUPPORTED ON 45 -105 M RECTANGULAR PILES

Ø LONGER PILES WHERE DEEP BED ROCK- TO AVOID DIFFERENTIAL SETTLEMENT Ø M 45 CONCRETE USED FOR PILES Ø 13200 cu m OF M 60 CONCRETE USED IN RAFT Ø CHILLED WATER USED- MINIMIZE DIFFRENTIAL TEMPERAURE

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

FLOOR PLAN

CORE WALL LAYOUT

COLUMNS Ø COLUMNS CAST IN REUSABLE STEEL FORMS Ø FINELY FINISHED COLUMNS OPEN TO VIEW AT MOST OF THE FLOORS Ø 16 TOWER COLUMN- VARRY ALONG HIGHT IN DIA. Ø 2. 4 m TO 1. 4 m DIA Ø CONCRETE VARRIED FROM M 80 TO M 30 IN 3 STEPS Ø 12 BUSTLE COLUMS – 1. 4 m TO 1 m Ø SETBACKS AT 60, 73 AND 82 Ø SLOPING COLUMS OVER 3 STOREY HEIGHTS Ø ABOVE FLOOR 84 – HIGH SLOPE – STEEL COLUMN USED TO AVOID COMPLICATION

COLUMN SIZE AND COLUMN GRADE

SLOPING COLUMN

BEAMS Ø TAPERED RING BEAMS ALL AROUND Ø DEPTH 1. 15 m AT COLUMN TO 725 mm AT FLAT ZONE Ø SPAN VARIATION DUE TO COLUMN CHANGES AND SET BACKS Ø BEAM GRADE MATCHES COLUMN GRADE TO SIMPLIFY PUMPING OUTRIGGERS Ø E-W OUTRIGGER LINK CORE AND COLUMNS AT FLOOR 38 -40 Ø 3 LEVEL BEAMS LINKED BY MID SPAN POSTS – HELP RESIST WIND EFFECT

SKY BRIDGE Ø DOUBLE DECK BRIDGE SPANNING 58. 4 m Ø CONNECTS TWO TOWER AT SKYLOBBY ELEVATOR TRANSFER STATION Ø ON FLOOR 41 AND 42 Ø EASY CIRCULATION B/W UPPER TOWER FLOORS Ø MINIMIZE LIFT USAGE Ø REDUCES FIRE EXIT REQUIREMENT Ø GREAT HEIGHT AND SPAN Ø REQUIRES STEEL FOR LIGHT WEIGHT AND EASY CONST. Ø TWO HINGED ARCH SUPPORTS THE SPAN Ø SELF CENTRING ACTION FROM RESTRAIN AT ARCH CROWN AND SPHERICAL PIN AT SUPPORTS

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

PINNACLE ELEVATION

DYNAMIC STUDIES Ø CROSS WIND EFFECTS ON STRUCTURE AND USER COMFORT Ø ANALYTICAL MODELLING : § 3 D MODELLING USING SAP 90 § INCLUDING PERIMETER BEAMS, COLUMNS, CENTRAL COLUMN REPRESENTING CORE & OUTRIGGER SYSTEM § COLUMN GROSS CROSS SECTION PROPERTIES USEDCOMPRESSIVE STRESSES DOMINANT § ELASTIC MODULI ‘E’ VALUES VARIED WITH STRENGTH ACCORDING TO ACI 318 § ‘E’ VALUES NOT REDUCED FOR CREEP- SHORT TERM WIND LOADING § BEAMS ASSUMED TO BE ‘CRACKED’- AVG. STIFFNESS I/2

Ø WIND MODELLING § DESIGN WIND 35 m/s ASSUMED AT 10 m 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 Ø SIMILAR DYNAMIC MODELLING DONE FOR SKY BRIDGE, PINNACLE Ø SKY BRIDGE REQIRED TUNED MASS DAMPERS-3 EACH LEG

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