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US 50/301(Chesapeake Bay Bridge)

Started by 74/171FAN, June 18, 2009, 08:56:47 AM

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Jardine

Any looming theoretical limits to the length of a cable stayed span ?

Compression in the deck near the towers springs to mind, but just add more concrete, no ?

(like in the typical precast deck segments typical used, but instead of them being identical the length of the bridge, progressively thicken the walls of the segments near the towers.

As for wind loading, similar effects on much longer (true) suspension bridges have been dealt with.

As for vulnerability of the span to wind prior to completion, how the heck do they deal with that now?  Seems like a deal killer for several already built, so there must be something they due to moderate the risk.


froggie

Quote from: AlexandriaVA on February 18, 2016, 11:41:53 AM
Quote from: jwolfer on February 18, 2016, 10:59:24 AM
My brother lives in Calvert County.  They would probably fight a new bridge there.  The county does not want a metro line extended to Calvert County, they keep lot sizes large, limit the size of big box stores etc to limit development.

Nor does anyone else...

Tell that to Fairfax (SE, Centreville) and Prince William (Potomac Mills, Manassas) Counties...

cpzilliacus

Quote from: Jardine on February 18, 2016, 01:25:56 PM
Any looming theoretical limits to the length of a cable stayed span ?

Compression in the deck near the towers springs to mind, but just add more concrete, no ?

(like in the typical precast deck segments typical used, but instead of them being identical the length of the bridge, progressively thicken the walls of the segments near the towers.

As for wind loading, similar effects on much longer (true) suspension bridges have been dealt with.

As for vulnerability of the span to wind prior to completion, how the heck do they deal with that now?  Seems like a deal killer for several already built, so there must be something they due to moderate the risk.

Longest suspension span currently is this: Akashi Kaikyō Bridge

Norway is considering a much longer main suspension span (not cable-stayed).

Highway E39 over the Sognefjord (pronounced "sonyfior"), with a main span of almost 4 kilometers (!) in length.  English-language video here of the extremely long bridge and other alternatives here.  English-language report here (.pdf).
Opinions expressed here on AAROADS are strictly personal and mine alone, and do not reflect policies or positions of MWCOG, NCRTPB or their member federal, state, county and municipal governments or any other agency.

cpzilliacus

Quote from: jwolfer on February 18, 2016, 10:59:24 AM
My brother lives in Calvert County.  They would probably fight a new bridge there.  The county does not want a metro line extended to Calvert County, they keep lot sizes large, limit the size of big box stores etc to limit development.

Don't worry about Metro.  The closest it could ever come to Calvert County is an extension of the Green Line to Waldorf, and even that is beyond the current planning horizon.

Regarding big box retail, even been down Md. 2/Md. 4 lately?  Plenty of big retail around Prince Frederick right now.
Opinions expressed here on AAROADS are strictly personal and mine alone, and do not reflect policies or positions of MWCOG, NCRTPB or their member federal, state, county and municipal governments or any other agency.

jwolfer

Quote from: cpzilliacus on February 18, 2016, 04:48:20 PM
Quote from: jwolfer on February 18, 2016, 10:59:24 AM
My brother lives in Calvert County.  They would probably fight a new bridge there.  The county does not want a metro line extended to Calvert County, they keep lot sizes large, limit the size of big box stores etc to limit development.

Don't worry about Metro.  The closest it could ever come to Calvert County is an extension of the Green Line to Waldorf, and even that is beyond the current planning horizon.

Regarding big box retail, even been down Md. 2/Md. 4 lately?  Plenty of big retail around Prince Frederick right now.
My brother lives near Dunkirk.. He and his wife call their local Walmart the small-mart because its size.. They said it's because of County zoning.. SIL is from rural Georgia the land of super mega Walmart

cpzilliacus

Quote from: jwolfer on February 18, 2016, 07:47:10 PM
My brother lives near Dunkirk.. He and his wife call their local Walmart the small-mart because its size.. They said it's because of County zoning.. SIL is from rural Georgia the land of super mega Walmart

I spent a lot of my childhood and youth in the Deale area of a nearby part of Anne Arundel County, where my late grandparents lived, and know Calvert County very well.

The county is not known for being excessively intrusive in matters of commercial and business development, at least by Maryland standards (FWIW, a huge amount of the county's property tax revenue comes from two properties in the Lusby area - Excelon's Calvert Cliffs Nuclear Power Plant and Dominion's Cove Point LNG Terminal).
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mattpedersen

The other thing that needs to be considered with a Southern crossing is that 2-4 would need substantial upgrades. The current road geometry barely supports the current traffic flow. The Prince George's and Anne Arundel segments would probably need to be widened to 3-4 lanes, and then everything South would need to look more like MD 210.

AlexandriaVA

Quote from: froggie on February 18, 2016, 01:26:50 PM
Quote from: AlexandriaVA on February 18, 2016, 11:41:53 AM
Quote from: jwolfer on February 18, 2016, 10:59:24 AM
My brother lives in Calvert County.  They would probably fight a new bridge there.  The county does not want a metro line extended to Calvert County, they keep lot sizes large, limit the size of big box stores etc to limit development.

Nor does anyone else...

Tell that to Fairfax (SE, Centreville) and Prince William (Potomac Mills, Manassas) Counties...

Come on, you know very well that WMATA is done with system expansions until more capacity comes along.

If anything, expansion out to Dulles was most justifiable because of a lack of potential RoW for VRE out that way.

Seeing as Metrorail in the areas you mentioned would amount to commuter service, I've always said more VRE is needed. In a fantasy world they'd be running hourly DMUs from the ends of the current system to Union Sta.

froggie

QuoteCome on, you know very well that WMATA is done with system expansions until more capacity comes along.

Do you even realize the dichotomy in what you just said here?

QuoteSeeing as Metrorail in the areas you mentioned would amount to commuter service, I've always said more VRE is needed. In a fantasy world they'd be running hourly DMUs from the ends of the current system to Union Sta.

Not all of it.  VRE wouldn't do squat for southeast Fairfax, where there is STRONG local support for extending the Yellow Line to Fort Belvoir.  Furthermore, such a Yellow Line extension would A) enable redevelopment of several existing commercial nodes along Route 1, and B) enable more direct transit commuting (and reverse commuting) to Fort Belvoir, which actually GREW as a result of BRAC instead of being cut.  Neither of these outcomes would be the "commuter service" you claim they'd be.

Another fact:  a Yellow Line trip from a theoretical Fort Belvoir station would STILL be a shorter trip to Gallery Place than a trip on the Red Line from Shady Grove.

AlexandriaVA

I meant to say "core capacity" (namely Rosslyn Tunnel II) and I would like to think you know that's what I meant.

And, on that topic, no more strain on the Blue/Yellow trunk route until the issue with Rosslyn is addressed. Sorry, but there's an absolute need to restore the Blue Line before its ridership gives up for good.

Plus, will Fairfax ever allow the upzoning needed to justify the Metrorail routes you want? I'd like to see them get a TOD project right first before giving them more trackage.

cpzilliacus

Quote from: mattpedersen on February 19, 2016, 10:01:43 AM
The other thing that needs to be considered with a Southern crossing is that 2-4 would need substantial upgrades. The current road geometry barely supports the current traffic flow. The Prince George's and Anne Arundel segments would probably need to be widened to 3-4 lanes, and then everything South would need to look more like MD 210.

Agree.

Md. 4 south from Md. 258 (Bristol) in Anne Arundel County to its north junction with Md. 2 in Sunderland would have to have substantial upgrades, and Md. 2+Md. 4 from there south to a new access road to the bay crossing would need the same. 

SHA would also have to get moving on getting rid of the two remaining signalized intersections on Md. 4  in Prince George's County at Westphalia Road and at Dower House Road (these need to be eliminated anyway for reasons of safety - never understood why SHA (and before it was SHA, SRC) spent all that money to upgrade Md. 4 from south of Dower House Road to Md. 258, but left those three miserable signalized intersections south of I-95/I-495 - at least the one at Suitland Parkway is out for bids and will be gone fairly soon).

Additionally, Md. 2 from Edgewater in Anne Arundel County south to its junction with Md. 4 would likely need to be upgraded to four lane divided (which it probably needs now, give the number of serious crashes experienced, especially between Edgewater and the roundabout in Lothian).
Opinions expressed here on AAROADS are strictly personal and mine alone, and do not reflect policies or positions of MWCOG, NCRTPB or their member federal, state, county and municipal governments or any other agency.

cpzilliacus

Quote from: AlexandriaVA on February 19, 2016, 02:24:42 PM
I meant to say "core capacity" (namely Rosslyn Tunnel II) and I would like to think you know that's what I meant.

Core capacity on Metro (even just the Orange and Silver Lines) is not just the part that crosses under the Potomac River.  That's something the local news media gets wrong over and over and over again.  Core capacity is from Rosslyn all the way to the wye on the elevated tracks east of Stadium/Armory near the D.C. 295/Benning Road, N.E. interchange.

Quote from: AlexandriaVA on February 19, 2016, 02:24:42 PM
And, on that topic, no more strain on the Blue/Yellow trunk route until the issue with Rosslyn is addressed. Sorry, but there's an absolute need to restore the Blue Line before its ridership gives up for good.

Are you aware of the potential cost of a mid-town line?  Billions and billions and billions of dollars, and do not count on Maryland being willing to contribute one cent toward construction costs.

There is a more-important reason for not extending the rail system right now - there are many repair and replacement projects that need to happen along the existing system, and that must take priority until the maintenance backlog is reduced.

Quote from: AlexandriaVA on February 19, 2016, 02:24:42 PM
Plus, will Fairfax ever allow the upzoning needed to justify the Metrorail routes you want? I'd like to see them get a TOD project right first before giving them more trackage.

They certainly have upzoned around the Dunn Loring rail station on the south side of I-66, and at Vienna too.
Opinions expressed here on AAROADS are strictly personal and mine alone, and do not reflect policies or positions of MWCOG, NCRTPB or their member federal, state, county and municipal governments or any other agency.

SteveG1988

Would it be safe to have the oldest span be dedicated to peak travel direction?
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froggie

The only way that could be done is if the third span is built south of the existing spans.

SteveG1988

Quote from: froggie on February 20, 2016, 12:28:36 PM
The only way that could be done is if the third span is built south of the existing spans.


Which would allow for a much longer curve to land on the western end.
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cpzilliacus

#65
Quote from: SteveG1988 on February 20, 2016, 03:33:23 PM
Quote from: SteveG1988 on February 20, 2016, 03:33:23 PM
Quote from: froggie on February 20, 2016, 12:28:36 PM
The only way that could be done is if the third span is built south of the existing spans.

Which would allow for a much longer curve to land on the western end.

Unlikely it would be north of the existing bridges, because of the presence of Sandy Point State Park there.  Section 4(f) of the U.S. Department of Transportation Act would make that difficult.

Regarding the curves, I suspect that a third span here would be reasonably parallel to the existing eastbound (1952) bridge.
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D-Dey65

Quote from: froggie on February 20, 2016, 12:28:36 PM
The only way that could be done is if the third span is built south of the existing spans.
So, a new span in the middle replacing the two of them would be impossible? Because it didn't look that way when I was there.

froggie

QuoteSo, a new span in the middle replacing the two of them would be impossible? Because it didn't look that way when I was there.

Correct, that would be impossible.  Not enough spacing in between the existing spans relative to their height, plus the spacing narrows as one approaches the western end of the span.

SteveG1988

Quote from: froggie on February 20, 2016, 08:11:49 PM
QuoteSo, a new span in the middle replacing the two of them would be impossible? Because it didn't look that way when I was there.

Correct, that would be impossible.  Not enough spacing in between the existing spans relative to their height, plus the spacing narrows as one approaches the western end of the span.

Plus you would not want long bridges that close. Just incase something bad happens, only one span goes down.
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cpzilliacus

WTOP Radio: Remembering When There Wasn't a Chesapeake Bay Bridge

QuoteBy 1919, the demand and pressure for some sort of Bay crossing led to the inauguration of regular ferry service between Annapolis and Claiborne, a 23-mile trip requiring two hours. Aside from the colonial ferry, this was the first regularly scheduled Bay ferry service in the State's history. Mounting pressure for a bridge culminated in 1938, with legislation authorizing the crossing, but World War II postponed the efforts. Under the leadership of Governor William Preston Lane Jr., during the regular and extraordinary sessions of the 1947 General Assembly, the State Roads Commission was directed to proceed with building a Bay Bridge.

QuoteAll earlier proposals for a bridge had planned for a crossing in the Bay Shore-Tolchester area. However, by 1938, the growing network of highways on the East Coast, the need to avoid hazardous navigation and the need to provide access to the lower Eastern Shore made a bridge location in the Sandy Point-Matapeake area most desirable.

QuoteAfter four decades of planning and waiting, the first shovelful of earth was turned in January 1949, in the area now occupied by the western approach roadway – and the largest public project in the history of the State had begun. Underwater work began, and the first permanent piles were driven into the Bay's bottom in March 1950. By the end of the year, the bridge was more than one-third complete. The underwater work had been finished, including construction of the massive concrete piers to support the main towers and the anchor piers to hold the suspension-span cables.
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cpzilliacus

There will be an online meeting on Wednesday, November 15, 2017 at 7:00 PM to discuss the Chesapeake Bay Crossing Study: Tier 1 NEPA (Bay Crossing Study).

Details on this site: http://baycrossingstudy.com/ 
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cpzilliacus

Baltimore Sun: As Maryland scouts locations for new Chesapeake Bay Bridge, hope and opposition emerge

QuoteTrey Hill uses satellites and precision farming technology to maximize his wheat, corn and soybean yields here in Kent County. If the planned third bridge across the Chesapeake Bay landed here, he says, it would destroy the natural barrier between Baltimore on his quiet, 300-acre farm.

QuoteFarther south on the Eastern Shore, Danny Thompson wants to preserve that type of quaint appeal. But as the director of economic development in Somerset County, he sees a new bridge as a potential boon, bringing more residents and tourism.

QuoteSuzanne Konigkramer, a Kent Islander who commutes across the current bridge daily to work in Annapolis, likes the idea of a third span to alleviate gridlock. Just please, she asks: find somewhere else to put it.
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triplemultiplex

Is it too obvious to put a new bridge in between the two existing ones?  The main spans are quite far apart.
"That's just like... your opinion, man."

froggie

Spacing concerns with both construction and maintenance would likely preclude putting it in between.  There's a reason the existing westbound span was built as far from the original (current eastbound) span as it was.

cpzilliacus

Quote from: froggie on March 16, 2018, 01:17:39 PM
Spacing concerns with both construction and maintenance would likely preclude putting it in between.  There's a reason the existing westbound span was built as far from the original (current eastbound) span as it was.

I agree.  If a new span were to be built parallel to the existing two, it would need to go south of the "old" (1952) 2-lane span that normally runs eastbound only.  North of the "new" (1972) 3-lane span probably means unacceptable impacts on Sandy Point State Park. 

And there's at least some room south of the old span for a bridge landing on the western side of the crossing, by using the former area where the ferry had a slip prior to the opening of the "old" bridge.
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