Tunnelling of Klang Valley Mass Rapid Transit

KVMRT brought the attention about the tunnelling of multi-billion My Rapid Transit (MRT).

Boring in the city (The Star)

Monday March 19, 2012

By Meng Yew Choong
star2@thestar.com.my

Building the award-winning dual-purpose tunnel called SMART was difficult enough. But building the Klang Valley MRT tunnel will have engineers pushing the envelope even more.

By next month, engineers and contractors who are into tunnelling will be fixated on a 9.3km underground strip of land that runs through one of Kuala Lumpur’s most developed parts. The stretch, which forms a crucial part of the Klang Valley Mass Rapid Transit (KVMRT) infrastructure, starts near the intersection between Jalan Semantan and Jalan Duta, before snaking through KL Sentral, Pasar Seni, Bukit Bintang, Stadium Merdeka, and Pasar Rakyat, before reemerging near Taman Miharja.

Like all metro tunnels, the KVMRT’s underground infrastructure will be built in the form of twin tunnels mostly running side-by-side to enable trains to rapidly traverse both directions. Work will begin in earnest once the successful bidder for the multibillion-ringgit tunnelling portion of this massive project is announced by MRT Corporation.

The dual, or twin-bore, tunnels will enable trains to run up and down from Sungai Buloh to Kajang along a 51km-long track that is intended to transform the way Malaysians commute.

This Tunnel Boring Machine was used to create the SMART; the machine that will be used in the even more difficult KVMRT project will be similar, though probably more advanced.

The tunnels will connect seven underground stations at KL Sentral, Pasar Seni, Merdeka (after Stadium Merdeka), Bukit Bintang Sentral (near Lot 10), Pasar Rakyat, Cochrane, and Maluri (see kvmrt.com.my for exact location of stations).

Over the next five years, Klang Valley drivers can expect to see some road diversions to facilitate the construction of the track, both for the elevated as well as underground portions.

Work on the elevated portion would, of course, be easily visible to all, and hence, road users will have a sense of the progress of the construction; but tunnelling will remain largely hidden.

One may ask how difficult could tunnelling be, given the continuous technological advancement in the field, as well as extensive knowledge now available in the Klang Valley courtesy of tunnels built for the Putra LRT (now part of Rapid KL) and the award-winning 9.7km Stormwater Management and Road Tunnel (SMART).

However, those who are in the know think that the company that successfully bids for the KVMRT project will be facing an unprecedented challenge in completing the 9.3km tunnel running under some of Kuala Lumpur’s most heavily developed areas on time and on budget.

To get an idea of the difficulties posed by this project, we held a teleconference interview with a German tunnelling expert.

“Boring the SMART was slightly easier in the sense that it did not have to pass through developed areas characterised by deep foundations,” says Dr Bernhard Maidl, a tunnelling expert with Maidl Consulting Engineers located at Bochum, Germany.

Maidl certainly knows what he is talking about as he has assisted in building over 100 tunnels worldwide, and has extensive knowledge of the tough geological conditions found under Kuala Lumpur.

The difficulties in building the SMART were not really made known to the public while work was being done; it was only after its completion that we came to know that it was no walk in the park even though state-of-the-art (at that time) tunnel boring machines (TBMs) were used.

This sinkhole appeared in Jalan Chan Sow Lin, Kuala Lumpur, during tunnelling works for the karstic portion of the SMART in 2005. Knowledge and experience derived from that project as well as more sophisticated technology should minimise such incidents today.

Deep complications

The TBMs were needed to punch a smooth hole through the highly-weathered limestone on which Kuala Lumpur sits. These types of landforms are called karst by geologists, and are generally the result of mildly acidic water acting on weakly soluble bedrock such as limestone (which is mainly calcium carbonate).

Water, either rainwater or groundwater, will gradually dissolve the surface along fractures in the limestone bedrock. Over time, these fractures enlarge as the bedrock continues to dissolve. The openings in the rock will increase in size to form underground drainage systems that will, in turn, allow more water to pass through the area and accelerate the formation of underground karst features after thousands, if not millions, of years.

The erosive and corrosive power of acidic water works its magic to leave behind a labyrinth of passages, steep drops and huge caverns (just like those seen in Perak’s Gua Tempurung, or in other exposed limestone hills).

Engineering-wise, Kuala Lumpur’s karst is classified as “extreme karst” (5 on a scale of 1 to 5) – it has an intricate underground network of channels that can go in any direction, steep sided cliffs, soft in-filled valleys, and a highly irregular rock heads.

Cavers would know all these terms, as they love to explore such features – but they are a tunnel engineer’s absolute nightmare as these features are the same ones that can cause sinkholes and ground subsidence during tunnelling.

Karst sinkholes and ground subsidence happen when disturbances to the underground water table causes earth and other debris to shift; this can happen when the TBM pierces underground reservoirs or water-filled cavities, thus disrupting the fine equilibrium of the system. Another possible consequence are mudflows (known within the industry as blowouts), which can rise to the surface during the boring process.

With the exception of a few hundred metres at both ends, the SMART was basically bored through highly weathered karst, which provided the engineers with a good learning experience in constructing structures under Kuala Lumpur. Extreme karst gave the builders of the SMART plenty of headaches, as dozens of sinkholes and mudflows occurred unexpectedly during construction of the dual-purpose tunnel that lies at depths of between 10m and 16m from the surface.

During the excavation of a tunnel through soft, water-bearing ground, a temporary support is often required to maintain the stability of the working face. In some cases, this support is provided by slurry, a thick suspension of solids within a liquid (usually a pressurised mixture of bentonite and water). Occasionally, this muddy mixture can reach the surface through fissures in the ground, causing what is known as a blowout. Seen here is an instance of slurry blowout at Jalan Tun Razak, Kuala Lumpur, during the SMART’s construction.

However, experienced tunnellers know that they can, to a large extent, mitigate these incidents through careful and deliberate pre-excavation treatment, which largely entails filling up the cavities and voids with grout before the boring machine passes through that stretch. But in order to know where the cavities are, extensive soil sampling and geophysical tests (using sonar and electrical resistance, for example) are necessary to ferret out these anomalies; this is what the winning bidder for the multibillion-ringgit KVMRT project must do to minimise the possibility of ground subsidence in the heart of Kuala Lumpur.

Over 150 bore holes have already been dug for initial studies, and the data have been published in the tender document for the KVMRT project; and despite the enormity of the task, there are already five interested parties vying for the job, including MMC-Gamuda, the only local consortium shortlisted.

Whoever gets the job will face the prospect of tunnelling at an average depth of 30m while doing their utmost to avoid, for instance, a sinkhole appearing in Jalan Bukit Bintang – can you imagine the chaos caused by closing one of the country’s busiest – and, arguably, commercially most important – streets? Ground subsidence is also a no-no at places where there is existing critical infrastructure like railway lines, major highways and even existing tunnels – yes, the KVMRT tunnel will have to pass under the SMART.

Thankfully, preliminary soil sampling for the tunnelling portion has indicated that only half of the KVMRT tunnel will pass through karst formations. The other half of the tunnel will go through the much more predictable formation composed of sedimentary rocks called the Kenny Hill formation (see graphic below).

Most of Kuala Lumpur sits on either one of these formations, which hold very different implications for engineering, even for things as simple as putting in a single pile. For example, the Kuala Lumpur City Centre project that hosts the Petronas Twin Towers was shifted just so it could sit on the more predictable Kenny Hill formation, rather than being built on the riskier karst.

Sedimentary rocks are formed under relatively uniform conditions over relatively large areas; this permits relatively accurate interpretation between data points and projections. As such, tunnelling works through the Kenny Hill formation should be relatively easy to manage during the design and construction stages. This should be good news for fans of Jalan Sultan in the heritage enclave of Chinatown, as the stretch sits on the Kenny Hill formation, which means it is extremely unlikely that complications will arise when tunnelling through this portion.

Spiralling difficulty

To minimise ground subsidence in such challenging geological conditions, and particularly so in a densely urban environment such as Kuala Lumpur, whoever gets the contract is expected to use the most sophisticated tunnel boring machines available, coupled with extensive ground investigations and comprehensive pre-tunnelling soil treatment.

Dr Markus Thewes, a professor at the Institute for Tunnelling and Construction Management of Germany’s Ruhr-University (who joined Maidl at our teleconference), predicts that significant improvements in knowledge of karst terrain and tunnelling technology will come in handy for whoever builds the KVMRT tunnel.

“Many improvements in tunnelling technology have taken place over the past two years, and I would expect that these technological improvements should be in place for the project. Sinkholes arising from tunnelling, if they occur at all, will be very rare compared to previous tunnelling works in the same kind of formation.”

An outcome of the failure to allocate a rail transport corridor during the nascent years of Kuala Lumpur’s development means that engineers have little option even in tunnel alignment when they designed the KVMRT tunnel.

Other than the many deep foundations of tall buildings to avoid, there is also utility infrastructure like sewerage lines, telecommunications cables, electricity cabling, water pipes, and gas pipes to contend with. At Kampung Pandan, the KVMRT tunnel has to go down as deep as 50m to maintain a safe distance as it passes under the SMART.

At Bukit Bintang Central, the underground space is so narrow that the twin tunnels have to be stacked on top of each other, rather than being laid side-by-side as in all other areas. This means that one tunnel would have to be dug in such a way that it forms a mini spiral to one side, just so that it can be on top of the other tunnel, before curving back to the side-by-side formation after it passes the Bukit Bintang area!

According to Maidl, all these factors combine to create some of the most unique tunnelling challenges ever.

“Building the KVMRT tunnel will require an extremely high level of knowledge and experience, right from the selection of contractor and consultants, to the design as well as execution levels. Everyone on the project needs to be experienced, as the tunnel goes through very public areas with a lot of traffic.”

Deadline for Chinatown traders

An ultimate deadline has been given by MRT Corp to very last two owners in Chinatown. It further says that compulsory acquisition will supersede if owners still reject the mutual consent agreement.

Month-end deadline for unhappy Chinatown traders (TMI)

By Clara Chooi

February 24, 2012

KUALA LUMPUR, Feb 24 — Traders along the iconic Jalan Sultan here will have their properties acquired by next week if they persist in rejecting MRT Corporation’s proposal to strike a mutual agreement.

Under the mutual agreement, mooted by MRT Corp chief executive officer Datuk Azhar Abdul Hamid (picture), the traders would continue to hold their property rights but would be required to vacate their premises for a six-month period to facilitate tunnelling work for the underground portion of the Klang Valley Mass Rapid Transit (MRT) Sungai Buloh-Kajang line.

But without their consent to the agreement, said Azhar, MRT Corp would have no choice but to allow the government to proceed with the compulsory land acquisition process under Section 8 of the Land Acquisition Act.

Speaking at a press conference today, he expressed disappointment that despite MRT Corp’s efforts to engage with all stakeholders in the area, the owners of two properties on the famous Chinatown street have continued to reject their offer.

“Now, we have no choice but to allow the (land acquisition) process to proceed.

“The feedback that we are getting is that it is just these two (property owners) who keep insisting on a realignment of the MRT... we are talking to the lawyers of the rest, the rest understand the situation,” he said.

Today’s press conference was organised to clear confusion over concerns raised repeatedly by traders that their properties would be acquired despite MRT Corp’s mutual agreement proposal.

Azhar said the traders were spooked by letters from the Land and Mines Office regarding the compulsory acquisition process, fuelling fear that MRT Corp would renege on its promises.

“They are saying now that its a credibility issue. But it is not... these are two different processes,” he said, referring to the government's land acquisition process and MRT Corp's mutual agreement proposal.

Azhar explained that the government office was just following standard procedures and gave his assurance that once the traders consented to the mutual agreements, this would override the compulsory acquisition process.

“So the faster we can mutually agree, then we can tell the government — can you please withdraw this and stop sending letters to the traders,” he said.

Azhar noted however that he was running out time for the negotiation as the MRT project must be delivered by July 2017.

He said the mutual agreement proposed was a “winnable formula” for the traders as it would not only ensure they keep their property rights but would also see them fully compensated for any loss of income during the six-month period they are required to vacate their premises.

Azhar also gave his assurance that the period would not coincide with the Chinese New Year celebrations, noting that this was considered a peak period for businesses in Chinatown.

He went a step further by offering to help traders gazette the area as a heritage site.

“I’d be sincerely glad to help,” he said.

The Malaysian Insider reported in December that landowners in Imbi had agreed to surrender a portion of their underground land rights to MRT Corp for tunnelling work.

The agreement appeared to be a coup for Azhar, who is under pressure to resolve ongoing land acquisition issues which he has warned may delay the completion of the MRT by up to six months.

The dispute began soon after landowners in Chinatown, Imbi and Bukit Bintang were informed in mid-2011 that the government would acquire all lots lying above the MRT tunnel as owners’ rights extend to the centre of the earth under the law.

Land Public Transport Commission (SPAD) chief executive Mohd Nur Kamal said landowners could then apply for stratum titles but added there was no guarantee Putrajaya would re-alienate the surface land back to them.

Critics have questioned the need for compulsory acquisition of both surface and underground land as the National Land Code 1965 was amended in 1990 to allow underground land to be acquired without affecting surface rights.

Unhappy landowners have mounted a high-profile campaign marked by numerous protests, signature drives and accusations that Putrajaya was conducting a “land grab” in order to defray project costs.

The multibillion ringgit MRT, meant to ease traffic congestion in the Klang Valley, is Malaysia’s most expensive infrastructure project to date.

The SBK line will cover a distance of 51km, of which 9.5km — including seven of the 31 stations — will be underground.

In reply:
Jalan Sultan shopowners worry over MRT Corp’s ultimatum (The Star)

Pre-qualified bidders for MRT tunnelling project

KVMRT has get the news on the pre-qualified bidders for MRT tunnelling project. Only one Malaysian company, Gamuda-MMC is in the run with five other foreign bidders.

Gamuda-MMC faces lower bids from pre-qualified bidders for MRT tunnelling project (The Star)

PETALING JAYA: The front runner for the mass rapid transit (MRT) tunnelling project – the Gamuda Bhd-MMC Corp Bhd joint venture – may be put in a tough spot to match the lower bids from some of the pre-qualified bidders, industry sources said.

Yesterday a financial newspaper reported that five companies had been pre-qualified for the project, including Gamuda-MMC, China’s Sinohydro Group Ltd, South Korea’s SK Holdings and two other parties from China and Japan.

Gamuda-MMC was the only local company shortlisted.

Reliable sources have confirmed this.

In an e-mail reply to StarBizWeek, Gamuda said: “We have not been informed of being shortlisted.” It didn’t reply to other questions in the e-mail.

The tunnelling works for the MRT is estimated to cost RM7bil and the financial newspaper reported that the pre-qualified parties had three months to submit their bids.

It had been reported that the project delivery partner (PDP) of the MRT project, Gamuda-MMC, would have the upper hand in bidding for the job as it was given the right to match the lowest offer from other bidders for the tunnelling job under the Swiss challenge system (Gamuda-MMC has to match the lowest bid to win).

However, bidders from China are said to pose a threat to Gamuda-MMC due to their expertise and experience in tunnelling jobs as well as having the financial muscles to undertake the project.

A reliable source added that local parties have a price advantage of between 3.5% to 7.5%, depending on the level of local and bumiputra equity participation in the project.

“However even with this price advantage, Gamuda-MMC could still be hard-pressed to match the pricing of some of the other bidders,” an industry source said.

Meanwhile OSK Research pointed out that while there was a risk of the other four pre-qualified names “under-cutting in their bids, we believe the local JV (Gamuda-MMC) still has an edge.”

“As the MRT is funded by the Government, we believe it would like to keep the job largely in the hands of local contractors.

“Furthermore Pemandu (Performance Management and Delivery Unit) had also previously stated that under the Economic Transformation Programme, the awarding of contracts to foreigners would also depend on whether these would have a positive impact on the GNI (gross national income).”

OSK expected Gamuda-MMC to be prequalified for the project, “given Gamuda’s experience with the Penchala Tunnel, Smart Tunnel and Kaohsiung MRT.”

The research house said it expected the award to be made by the end of the first quarter of next year.

What is the criteria?
That maybe the most important question. To who government will awards the project package? The Malaysian government in awarding the jobs will have to weigh whether to go for the cheapest bid or for a higher one by a local player.

“There is no right or wrong, it’s just a matter of priorities,” the industry player said.

Global practices
“In most countries there are mechanisms to prevent foreign bidders from winning jobs, or even bidding. But don’t look at Hong Kong and Singapore, they have different economic models,” an industry player said. The barrier to entry for foreign companies can take many forms, from simple methods such as work permits or visas to more complex mechanisms.

In the European Union (EU) for instance, only EU-based companies are allowed to participate in EU Cohesion Fund projects.

It is the same for Japan International Cooperation Agency (JICA) loans, where it is understood that only Japanese companies will benefit from this funding.

Thailand requires that all tenders for the Bangkok MRT Blue Line are 51% led by local contractors.

“In China, a company must be incorporated there, in China, and must have completed at least three jobs. This is a chicken and egg situation. It would be great if local companies gain the expertise and can take their expertise abroad, much like the building of highways,” an industry player said.

My Rapid Transit launching on July 8

Klang Valley MRT (now referred to as MyRapidTransit) will be launched by the Prime Minister at KL Convention Centre on 8 July 2011.

The launching, which will take place in the morning and will include a ground-breaking ceremony, is by invitation only.

The event will also be telecast on RTM1 from 9:30-11am. Following this launching, the public is invited to learn more about the MRT from 12:00-7:00pm at KL Convention Centre.