Technical Site Visit to Ipoh-Padang Besar Electrified Double Track Project (EDTP)
Northern Region had organized a technical visit to Ipoh-Padang Besar Electrified Double Track Project (EDTP), Package C in Taiping on 25th June 2009. A joint venture consortium company between MMC Corporation Berhad and Gamuda Berhad has been awarded to develop the project for KTMB. The joint venture consortium company will design and build the Electrified Double Track Project (329KM) and the project will involve the construction of infrastructure works, track and system works on a 5-year Design and Build Contract. The EDTP is an extensive infrastructure project (a continuation of the completed stretch from Rawang to Ipoh) that would transform the existing single track line from Kuala Lumpur to Padang Besar to electrified double tracks line.
It was interesting to note that the site visit consisted of not only from Northern Region staffs but also from the Central and Southern Regions, NMM HQ and PEB staff as well. The group comprised of about 20 participants was led by Northern Region Engineer, Ir. Faisal Abd Rahman had assembled at Bukit Merah Toll Plaza at 9.30 a.m.
The group was greeted by representatives the Kinta Samudra, Emenea and Tekad (KSET) the project management team led by En. Khairi Khalid, the Construction Manager, accompanied by Hj. Shamsul Bahar Hamzah and En. Mohd Hafiz Othman at the Toll Plaza. As noted by En. Khairi, the participants will be given opportunity to tour the two (2) on-going main construction activities that are the Bukit Merah’s Marine Viaduct and the Larut’s tunneling works.
Bukit Merah Marine Viaduct
The group was given brief safety procedures especially on Personal Protective Equipments (PPEs) required by the project Safety Officer, Mr. Raja Mohan upon arrival at the assembly area. This is followed by a detail project backgrounds and progress updates given by Mr. Graham David Hobbs, the Project Manager. As explained, the viaduct is spanning across the Bukit Merah Lake and the swampy area to a distance of 3.4 kilometers in length. The viaduct construction had started from northern end bank traversing towards the southern end.
The structure is comprised of 900mm diameter hybrid spun piles driven from a piling barge until the hard layer an average depth between 15.0 meters to 20.0 meters. (Note: a hybrid pile is a reinforced concrete spun pile with an attached steel casing that act as a permanent starter casing). The main structure for the deck is the 15.0 meters length R.C. pre-cast T-beam of Grade 40 segments, weighing 43 tones each being transported from a casting yard located distance kilometers from the site. The sequence of works will be once the pile caps have been completed, the T-beams segments will be launched via a crawler crane of 150 tones capacity that sits on a barge. The concrete stitching of diaphragm structures will follow when the T-beam segments are arranged side by side to their pre-determined locations.
Mr. David mentioned several challenges faced by his team during construction works. Firstly, is to ensure the stability of the earth bund that support the existing track line that had resulting the marine viaduct alignment had to be shifted to run parallel to the existing railway line with an off-set 100 meters and several monitoring instruments and equipments are being placed and monitored daily. Secondly, to control the water quality as set by the DOE and DID since the Bukit Merah Lake is serving its water for domestic use, irrigation purposes and an interesting fact that it is a breeding ground for the famous Malaysia Red Arowana ornamental fish. Therefore its water quality needs to be sampled periodically and meet the requirements set by the authorities.
At the time when this report is written, the contractor had managed to complete 63 out of a total 231 nos. of piers for the marine viaduct. The entourage was given an opportunity to witness the launching of a T-beam segment during the said visit which ended at 11.45 a.m.
Later the group was headed to KSET project site office in Taiping for tunnel construction briefing. The briefing was presented by En.Khairi Khalid. who explained on the approaches in tunnel construction, the backgrounds of the two (2) Tunnels structure namely Berapit Tunnel a dual tunnel with a combined length of cost at RM 270M with 3.3 Km estimated to cost at RM270 millions and and Larut Tunnel with 330 meters estimated to cost RM30 millions and the sequence of works involved. The key elements of the excavation and support works are briefly described as follows:-
i. Probe holes are carried out in soil or completely weathered rocks.
ii. Installation of umbrella arches
iii. Installation of fibre glass elements
iv. Advancing, mucking and scaling
v. Installation of rock dowels concrete base slab where applicable
vi. Installation of water proofing membrane
vii. Sprayed shotcrete as primary tunnel lining
viii. The final concrete tunnel lining of Grade 35 using the sleeve formwork
Several instrumentation and equipment such as settlement markers, inclinometers were installed during construction period to monitor the surrounding area and tunnel structure integrity due to vibration.
En.Khairi Khalid also explained that for Berapit Tunnel construction, a combined methods of 24-hour drilling was made possible via a Tunnel Boring Machine popularly called “drilling jumbo” or a high speed drills (for drilling simultaneous holes at one time) and controlled blasting where specific requirements such day light and weather conditions.
Before concluding his presentation, En. Khairi Khalid explained the challenges facing during construction are due to strict requirements imposed by client (KTMB) such as compliance to environmental aspects as well as engineering setback because of the existence of high ground water, variable soil and residual rock profiles.
Due to safety reasons, the participants were only visited the Larut Tunnel construction site to gain first hand information and exposure of the works activities at site. The group managed to witness the final tunnel lining construction in progress and the sleeve formwork move to the next section after pervious section had been cured for 24 hours.
The site visit session finished at about 2.15 p.m. We wish to register our note of thanks to KSET staff led by En. Khairi Khalid. Most of the participants agreed it was a very informative and interesting visit.