PPG Malaysia “Bridge Enormous Gaps”
This project is part of the on-going widening of the existing Penang Bridge from 2 lanes to 3 lanes. UEM had contacted Megalift to propose and execute a method on how to shift 9 units of the existing emergency lay-by to make way for the new 3rd lane. Megalift then came out with the method of using their hydraulic gantries and skidding system. The hydraulic gantries would be used to jack-up/lift-up the lay-by off of its foundation and onto its new foundation and the skid system would be used to skid the lay-by 4.8m to its new position. The hydraulic gantries were positioned underneath the lay-by, 2 units on each pile cap, and the skid system positioned on top of the gantry.
|Project: Widening of the existing Penang Bridge – Shifting of emergency lay-by.Client: UEM Construction Sdn BhdCargo: Concrete lay-by segments weighing approx. 350 tons, 40m length. Total 9 units.Scope of work: Shifting of existing lay-by using hydraulic lifting gantries and skidding system to lift up the lay-by and skid to new position.Major equipments used:(1) 4 legs of hydraulic gantry – total lifting capacity of 800 Tons(2) 500T capacity skidding system(3) 1 unit 180ft barge(4) 150 ton crawler craneDuration of work: July 2008 – October 2008|
|The gantry would then lift up the lay-bys and act as a structural platform for the skidding system positioned on top of the gantry. Once lifted, the lay-by is skidded/shifted 4.8 meters by means of the skidding systems pull/push cylinders. Once the lay-by has reached its new position, the gantry would lower down the lay-by to sit onto its new crosshead.|
This job produced new challenges for Megalift as working space on the pilecaps and crosshead was very minimal and the Megalift workers were working in the sea, where all equipments and tools were transported via barge. The setting-up of the gantry system and the skidding system also had to be done from sea using a crawler crane positioned on the barge. Access to the working area was only accessible by sea making the work much tougher. Furthermore, before the lay-by could be shifted, it was crucial to first hack the existing diaphragms to free the lay-by form the original crosshead.
|The diaphragms had to be demolished before the setup works for the gantry and skid system could be completed. The hacking works were very much more difficult than anticipated. It took a team of 12 men and 120hrs of physical labor to complete the hacking of diaphragm for 1 lay-by. In the end, Megalift managed to successfully execute the job perfectly without any mishaps. The shifting of the lay-by was successfully completed much earlier than the allocated time frame of 7 days for each lay-by, to only 5 days. Some lay-bys were done in only 4 days. To date Megalift have completed shifting 5 units of lay-by and the balance 4 units are expected to begin by fourth week of September 2008. The project is expected to be completed by mid October 2008.|