SUNDAY, JUNE 5, 1994
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THIS SPECIAL LAUNCHING GIRDER WHICH HAS BEEN USED TWICE PREVIOUSLY IN EUROPE BUT ONLY ONCE BEFORE IN HONG KONG ON THE KWUN TONG BYPASS PROJECT WILL LIFT AND POSITION THE LARGE PRECAST CONCRETE SEGMENTS ON TOP OF THE BRIDGE PIERS
ΤΟ 30 METRES ABOVE GROUND LEVEL AND RAMBLER CHANNEL WATER LEVEL.
ענן
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BEEN TOTALLY BRIDGE, THE METRES LONG
ORIGINALLY FABRICATED IN ITALY, AND AFTER HAVING REFURBISHED AND EXTENDED FOR USE ON THE RAMBLER CHANNEL LAUNCHING GIRDER NOW WEIGHS 450 TONNES AND MEASURES AND 15 METRES HIGH.
120 TONNES, IS CANTILEVERING OF BOTH SIDES OF A
EACH SEGMENT, WEIGHING BETWEEN 80 AND POSITIONED BY THE LAUNCHING GIRDER AND DURING THE THE DECK SEGMENTS, ONE BY ONE ALTERNATIVELY ON BRIDGE PIER, EACH SEGMENT IS BOLTED TO THE NEXT ONE UNTIL THE CLOSING OF ONE SPAN IS ACHIEVED.
THE PROCESS IS THEN REPEATED UNTIL THE 1.2 KILOMETRES LONG BRIDGE DECK IS FORMED.
A SENIOR ENGINEER FROM THE HIGHWAYS DEPARTMENT, MR DUNCAN SIU, EXPLAINED THAT AN IMPORTANT ADVANTAGE OF THE BALANCED CANTILEVER TECHNIQUE WAS THAT CONSTRUCTION WORK WAS DONE WITHOUT TEMPORARY SUPPORT FROM THE GROUND AND THUS ELIMINATES THE NEED TO CLOSE OFF SECTIONS OF THE RAMBLER CHANNEL.
AS IT MEANS THAT
"THIS IS A VERY IMPORTANT CONSIDERATION DISRUPTION TO VESSELS MOVING THROUGH THE CHANNEL AS WELL AS HEAVY ROAD TRAFFIC ALONG THE TWO APPROACHES AT TSING YI AND KWAI CHUNG ARE KEPT TO A MINIMUN, MR SIU SAID.
P
"THIS TECHNIQUE UTILISING THE LAUNCHING GIRDER WILL ALSO CUT SHORT THE CONSTRUCTION PERIOD. IT ALLOWS THE CONTRACTOR ΤΟ ERECT UP TO 100 METRES OF BRIDGE DECK IN ONE WEEK, CONSIDERABLY FASTER THAN OTHER MORE CONVENTIONAL METHODS OF BRIDGE BUILDING, MR SIU SAID.
中申
"ALL THE PRECAST SEGMENTS CAN BE MADE IN A CENTRALISED PRESCASTING YARD UNDER GOOD QUALITY CONTROL. THE PRODUCTION RATE IS THEREFORE QUICKER THAN SOME CONVENTIONAL CAST IN-SITU CONCRETE CONSTRUCTION METHODS, HE ADDED.
"I
CONTRACT, AWARDED IN
THE RAMBLER CHANNEL BRIDGE CONSTRUCTION JUNE LAST YEAR TO DRAGAGES-BSG-PENTA JOINT VENTURE AT A COST OF $669.8 MILLION, COMPRISES THE BUILDING OF A 490 METRES LONG MAIN BRIDGE, AND APPROACH VIADUCTS ON EITHER SIDE OF THE CHANNEL.
THE PROJECT HAS HAD A SUCCESSFUL START AND IS CURRENTLY ON PROGRAMME FOR COMPLETION IN 1996. WHEN COMPLETED, THE ROUTE 3 RAMBLER CHANNEL BRIDGE WILL CARRY A DUAL THREE-LANE EXPRESSWAY.
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