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Service Life of Elevated Metro

ಮೇಲೆ
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Infrastructure

 There have been numerous debates on wether we take metro underground or do we have it on elevated structures..these have been mostly related to the following:

1. Number of tree cut and properties damaged

2. Cost of going underground

The first is not anymore a point of discussion as BMRCL has proved that equal/more number of trees will be cut for going underground.

The second point on cost is valid because the claim is going underground escalates the cost by 3 times.

However, there is a third point  on the life of elevated structures itself..

There are many references on google that the 'service life' of concrete bridges is about 75 years maximum..so does that mean the metro will be functional only for the next 75 years?

Is it because of this reason most metros around the world just go underground?

Parts of  Red line in Boston was constructed in 1912 and they have extended since then..most of the line is underground with some part at grade..

So wouldnt it make more sense that we go underground for most parts of namma metro now, though its gonna cost us more?

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Naveen's picture

Elevated Metro - Can be maintained

ಮೇಲೆ
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Blrsri,

With a U/G metro, trees can be replanted once construction is over + we will not have  ugly viaducts obstructing the skyline everywhere. The only problem is that U/G construction costs are very high.

It does not necessarily mean that Namma Metro will only last about 75 years since much of it is above the ground.

Viaducts can be maintained for very long periods - the bridges in New York across Manhattan & other boroughs (such as Brooklyn bridge) are very old & are being maintained by periodic replacement of weaker sections & corrosion resistant coating, etc.

Metros in many cities across the world are U/G since they could afford them so, I guess ! Also, perhaps, to retain open spaces & road widths. In New York, the "subway" is elevated in many areas outside Manhattan (Brooklyn, Queens, Bronx, etc.). In Washington DC also, the Metro surfaces from below ground & even runs elevated in some parts. Similarly, the Path system in NJ is U/G, but also has sections that are on surface - so, it's all usually dependent on the terrain, finances, projections & needs as decided at the time of construction that finally results in the outcome, I guess.

Even the "Underground" in London has a lot of it that is not below the ground, as do the Metros in Berlin, Munich or Singapore.

I agree that UG is the best - but the costs are too high for Indian cities in our current economic situation - since there are many other priorities that also need to be attended to.

 

 

gopi's picture

Service Life of Elevated Metro - Same as Underground tunnels

ಮೇಲೆ
83 users have liked.

Most of the cities has U/G in CBD and surfaces above once the network is out of the CBD.  This I think will help since the metro can take any route, without the constraints of the existing road network.

Regarding the life of UG or above ground the materials used for construction is still concrete and steel.  The difference might be that the tunnel will have to deal with the chemicals in the soil and the water, where as viaduct's should deal with weather.  There should not be any difference in the life time of the structures.

 
ssheragu's picture

advantages of ug metro over elevated metro

ಮೇಲೆ
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ssheragu

I have done some loud thinking on the benefits of UG metro over ELEVATED metro; these are given below.

                BENEFITS / Advantages of Underground Metro over Overhead Metro 

1.         Space requirement: construction of overhead metro requires a lot more space than construction of an underground metro;

2.            Demolition of structures it required demolishing a lot more structures than underground metro;

3.         Loss due to Traffic snarls: the losses it creates by way of traffic snarls is much more than that for underground metro;

4.         Traffic Deviations: inconvenience due to traffic jams are much more than that for underground metro

5.            Aesthetics: there is no comparison in aesthetics between underground metro and overhead metro; an underground metro is much more colorful, neat and orderly than an overhead metro; thus its revenue generation by way of tourism is much more than that of an overhead metro

 

6.            Cost Factor: since the life of any city is practically without any bound, no cost will be too big for any city; plus the cost of UG underground can be recovered in 10 or 15 years time

7.            Moreover, the metro can be planned in such a way, that, if there are a total of 10 lines in the metro, only 2 lines can be completely elevated; the rest 8 lines can be completely underground.

AT ANY RATE IT IS NOT AT ALL ADVISABLE TO HAVE PART OF A LINE ELEVATED AND THE REST OF THE LINE UNDERGROUND

many thanks

Srinath Heragu

blrsri's picture

why are we emulating DMRCL?

ಮೇಲೆ
82 users have liked.

When we know metro on stilts is not the way to go..why are we doing the way Delhi Metro is doing? Is it becos RITES and DMRCL planned the phases of our metro?

Shouldnt we relook at what we want, atleast for phase II?

Worried about money? Didnt we mobilize monetarily for the recent rain disaster? Cant we do similar for an everyday hazard affecting lakhs of ppl in blr?

Gopi:

About maintenance of UG Metro, its not as expensive as the stilt ones..cos the biggest cost of going ug is in the begining, during tunneling using TBM's. Once done..regular maintenance should not be an issue! 

Heres an excellent article on rails http://www.dailykos.com/story/2007/7/13/123245/546

idontspam's picture

 From the DailyKos

ಮೇಲೆ
91 users have liked.

 From the DailyKos link

Guangzhou Metro's current(2007) four lines totalling 89.7 km (55.7 mi) were built in a mere ten years, and just counting in-construction lines, network length is to triple by 2010! (ie 180kms to be added in 3 years)

So whats opening in Bangalore by 2010? 8kms?

s_yajaman's picture

Cost/benefits

ಮೇಲೆ
85 users have liked.

Agree on 1 to 5 (except for the tourist part - no one comes to a city because of an underground metro).  The big question is the upfront investment.  It's all very well to say that instead of investing Rs100 cr/km we will invest Rs300crore/km  If the total length is 150km that is a massive Rs.30,000 crores. 

With the difference we can add 200km more of elevated Metro.  This is 20 km of Metro on each of the Big10 roads.  Things don't have to be ugly.  The median of the elevated structure can have fountains and other greenery on them.  The pillars can have creepers, etc.

Also, we need to understand the subsoil and groundwater considerations.  These tunnels go quite deep - 10-20m.

Srivathsa

 

Drive safe.  It is not just the car maker which can recall its product.

blrpraj's picture

flooding & underground metro

ಮೇಲೆ
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Does anybody have any knowledge/information on the threat of flooding in a hypothetical underground Metro in Bangalore  during torrential rains? We know that many parts of Bangalore (and for that matter mumbai) are flood prone almost on a yearly basis during torrential rains, I wonder what would happen in such an event in underground Metro stations!

Another thing to keep in mind is the water table, if it is higher than the underground subway level then pumps will have to be run all the time (even if there is no rain) to keep the subway from flooding as is done in the New York subway system.

 

 

blrsri's picture

we are in the deccan..

ಮೇಲೆ
93 users have liked.

..and not in plains like Delhi or other cities and designing adequate drain system for the metro should not be too difficult because of grade variations!

Also abt the ground water table..this will soon be depleted everywhere, especially in the CBD, cos of over population..ppl are already digging 300-500 ft for water which was available at 200-300 abt 10 yrs ago..so drying out the surface shouldnt be a problem!

..just start a 'mineral water' plant (which bottles the water we have in offices) and that will take care of flooding..btw there are many already!

ssheragu's picture

elevated metro

ಮೇಲೆ
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ssheragu

so much is being said and talked on Praja about elevated metro; there are many diverse opinions about elevated metro & underground metro

may be it is high time a talk is arranged with Mr. Sivasailam MD, Bangalore Metro on this.

are Praja members  agreeable for this

many thanks

Srinath Heragu

blrpraj's picture

METRO - Elevated or not

ಮೇಲೆ
91 users have liked.

Srinath,

None of us are construction experts but looks like all of us kind more or less understand one thing that underground metro construction is prohibitively expensive. None of us probably know the exact costs and how much more expensive it is than an elevated Metro. Nor do we know the differences in operational costs of underground metro vs elevated metro. 

To me it seems like (this is just an educated guess/personal opinion) - underground metro has a high upfront cost in terms of construction but in the long run seems to be good because as metro expands land acquisition will not be a problem, we will have land available that can be put to other uses, also we will not have noise pollution as would be there in case of an elevated metro. I am not a geologist or construction expert but from the little knowlesge that i have gleaned from friends in the construction industry, underground construction has significant challenges. 

On the other hand, to me elevated construction seems to have lower upfront costs for construction;  I am not including land acquisition costs here but it would be interesting to see what the actual land acquisition costs are...it seems to be still lesser than going underground judjing by bangalore metro's decision to go elevated. I am not sure what the operational costs are though compared to an undergound metro. Downsides are noise pollution to surrounding localities, expansion would be difficult because of slow pace of land acquisition and legal battles, potentially an eyesore to bangalore's skyline especially given the pathetic maintenance of public spaces and infrastructure. 

Maybe Sivasailam can confirm if the above general understanding is correct..especially about the constructiion costs and challenges faced in both types of metro. Hopefull he would also be able to throw light perhaps and give correct figures on the operational costs in terms of some unit like per km per day. 

ssheragu's picture

elevated or ug metro

ಮೇಲೆ
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ssheragu

Happy Diwali to all of Praja

blpraj, you have given a good critical analyses of elevated versus ug metro; it makes it quite evident that a meeting with Sivasailam is absolutely necessary at the earliest;

considering our interest in metro, I would be happy to arrange a meeting with Sivasailam, if someone can provide his conatct nos. (I had earlier, but I have misplaced)

many thanks

Srinath Heragu

Vasanth's picture

Underground Metro vs Overhead Metro...

ಮೇಲೆ
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 Underground Metro is very expensive because of the following reasons:

1. Airconditioning in the tunnels.

2. Emergency Evacuation

3. Two methods of underground tunneling.. Cut and Cover and Tunnel Boring. Ends of the tunnel are usually cut and cover from where they start tunnel boring. In our case it would be Vidhana Soudha from where Metro will become elevated, Leprosy Hospital, Malleshwaram Sampige Road Entrance, Before Venkataramanaswamy temple near KR Market.

4. Tunnel Boring is the only method if the property above needs to be not disturbed like the downtown Bangalore of Chikkpet, Balepet.

5. All the Borewells and other wells in the surrounding area needs to be closed permanently.

6. Structure above the tunnel passes needs to be analyzed thoroughly.

7. Underground Metro generates lot of heat inside the tunnel. Without proper airconditioning, it is hot as I have experienced in New York subways and Boston redline.

8. Vibration of underground metro is more compared to overhead Metro which I have observed in Boston which has both. Barely we can notice any vibration of an overhead Metro.

9. Overhead Metro problems may be during earthquake or bridge collapse. Earthquake can damage even underground Metro and may lead to fire within the tunnel evacuation of which becomes highly complicated.

Overall overhead Metro is cheaper and easy to operate. Environmentalists demand otherwise, but trees may have to be chopped even for underground Metro if the roots are deep. Better is to avoid the green path such as Nanda Road and KR Road and pass through parallel roads.

Vasanth's picture

If roads are wide no demolition needed for overhead Metro

ಮೇಲೆ
89 users have liked.

 If the roads are wide, not much of space is needed for overhead Metro. In other words footprint is smaller.

Problem in Bangalore is, on MG Road, it was planned on the Boulevard rather than Median to preserve looks, CMH Road was too narrow, Nanda Road had trees as well as KR Road. Turnings needs some space which obviously needs properties.

If we observe the Vijaynagar Chord road junction stretch, there is neither property nor tree is destroyed. If 3 lane roads are available, then elevated Metro does not need any property destruction.

For instance, Hosur road BETL did not had any property destruction due to availability of space (3 lane road). Metro on the same stretch would not have destroyed any property.

If we compare pie to pie, even with property demolition, elevated Metro is far cheaper nearly 1/3rd of underground Metro.

blrsri's picture

cost factor deciding..

ಮೇಲೆ
84 users have liked.

..and we may not be in a position to afford underground now..lets see if our future generations can do any better! 

Vasanth's picture

Misleading Media

ಮೇಲೆ
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Media is misleading people a lot. See for example this report . bangalorebuzz.blogspot.com/2009/10/metro-is-not-solution-to-citys.html 

It says that people were not knowing that Metro does not pass under Vidhana Soudha. What else can be worse than people running our state not knowing where Metro passes. Metro route was posted way back in 2007 on bmrc website and we have discussed a lot on that in Praja. Metro officials cannot go to each and every individual and say Metro passes here, do you have any objection. BMRCL has become a football of Media, Politicians, Environmentalists and Social Activists.

People talk of Heritage and beauty of city being vanished. But, nobody commented when flyovers were constructed. Lots of people will be urinating against the walls of Tippu palace and nobody is there to protect. Vidhana Soudha is protected since MLAs and ministers sit there otherwise it would have the same status as Tippu palace. Same was the case for Tippu armery in Srirangapatnam for Mysore-Bangalore track doubling. I have been travelling from childhood and only now after the objections I came to know that it is Tippu's armery in Srirangapatnam station.

ssheragu's picture

metro overhead or u/g

ಮೇಲೆ
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ssheragu

I checked up. Mr. Sivasailam is available in his office from Nov 4 th

If any of us are interested to meet him and provide him our suggestions, I can arrange a meeting date with him

many thanks

Srinath Heragu

silkboard's picture

If we are going

ಮೇಲೆ
100 users have liked.

No offence, but if we are going in for a meeting, let us go with some preparation. This is so far a pure armchair expert thread, no data on costs, timelines etc so far. Examples (one from IDS) on timelines are from China - not fair. And there are some comments there that won't stand logical discussions. Ex: ssheragu's line: "not advisable to have part of line underground and part overground". Going by examples from a few European cities and pure logic - this is very illogcal reason or suggestion.

Please do not attend or organize such meetings without some thought out substance or preparation. Otherwise, next time, they will think twice before giving you time for a meeting.

Questions to ask BMRC are (and can be done over email, these must be like FAQs for them, they would have ready answers) :

  • Was a cost comaprison done for UG/OH options
  • In the cost angle - was maintenance cost also compared (UG vs OH)?
  • How was the length of UG portion determined? Cost angle, plus any other?
  • How did you determine the points where lines go from UG to OH - cost based calculations, or other considerations?

Let us first know more. And only then meet/ask them. We all know by now that doing preparations solely based on media reports is risky business.

blrsri's picture

No UG or OH discussions

ಮೇಲೆ
93 users have liked.

Probably we can pool in all types of questions and decide on the best few to put forward..

Mr Sivasailam has confirmed by mail that the ph2 DPR  would not come before Dec 2009..so maybe one request to him would be to include Praja folks in that..

s_yajaman's picture

My questions

ಮೇಲೆ
96 users have liked.

Not sure when the meeting is.  I am not in town Nov 5 and then from Nov 7 through 14.  If not on these dates, I will join.  My questions

a. Phase I - elevated.  Progress on different reaches in terms of civil works (piles, piers, spans).  reach 1 in more detail.  How are we tracking to Dec 2010 for opening Reach 1.

b. Phase I Underground - where are we on this?  When will the tunnel boring start?

c. Future plans - what is in store (roughly) on Phase 2?  What beyond? Is there any plan to put a line from Mysore Road to ITPL on ORR given the amount of traffic and economic activity?

d. UG vs OH  - why did we not do UG on MG Road?  Was cost the only consideration?  Were there other consideratons (sub soil. water tables,etc).

Will think of more

Srivathsa

 

 

 

Drive safe.  It is not just the car maker which can recall its product.

ssheragu's picture

U/G metro v/s Overhead metro

ಮೇಲೆ
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ssheragu

1. a lot many conflicting suggestions are being offered from various perspectives;

2. while I welcome silkboard's general suggestions, I am not totally inclined to accept that my objection to part U/G and part OVERHEAD metro is not logical; my objection is mainly from the point of view of aesthetics followed by maintenance of cleanliness; the argument against my suggestion is based on the comparison with European cities which are well developed countries; the general and average level of cleanliness, discipline, respect for law, order, education etc. is much better than ours; the comparison will stand the test of logic and time, only if it is made with such metro in developing country like ours; the scenario of a tunnel jutting out will not only be aesthetically very poor but will lead to easy access of the tunnel to anti social elements; at  the end of the day, if I am not able to stop Bangalore Metro from going part U/G and part OVERHEAD, I earnestly wish that I am totally wrong and silkboard is completely correct; 

3. I would suggest that all of us meet amongst ourselves, put forth our views, identify important suggestions and put forth the same to Mr. Sivasailam ( a mutually convenient date for a meeting with Mr. Sivasilam can be fixed after the meeting amongst ourselves) 

many thanks

Srinath Heragu

ssheragu's picture

metro u/g versus overhead

ಮೇಲೆ
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ssheragu

Hai Praja Freinds,

I presume that we are still open for a discussion with Mr. Sivasailam on (metro u/g v/s overhead)

If you guys can confirm any conveninet date, I can definitely strive to arrange a meeting with him.

many thanks

Srinath Heragu

idontspam's picture

Underground

ಮೇಲೆ
96 users have liked.

 I am for everything going underground including major corridor roads (like the big-dig). I want us to dig one decent tunnel in this city for something. Can we afford it? Maybe we can, if we knew how to fund it.

idontspam's picture

Metro Trinity station 12 Mar 11

ಮೇಲೆ
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