[DarkEconomist]

a major reason we don't see larger affordable developments is $$$.

another major reason is that government folks want to avoid creating large slums similar to the housing projects developed 50 years ago.

These really sum up why we're unlikely to see large-scale affordable projects.

Even if there was money to do these at a larger scale, we're hopefully past those top-down utopian idealizations of "helping" the poor by creating all-in-one complexes that one group thinks is everything the other group needs to be happy.

 

[bobby_guz_man]

i understood those timelines as 4 years to dig the entire tunnel, 240 days for the downtown station construction.

remember that with either option, there will be minimal surface disruption where there is no station.

So what you're saying is that, for most of the length of the tunnel, we won't see very much disruption. And only the Downtown Station and 24th Street would see any tunneling actions?

If that's the case, then I don't understand the hubbub over this whole thing? The Rapid Bus caused a lot of issues because it was done at surface level, I believe?

Honestly, let's just get the damn thing going. Sitting here fiddling back and forth just waste more time and make the cost rise higher. For the next 10 years the Berryessa station is going to continue shipping workers off to the East Bay, rendering that neighborhood a bedroom community for Oakland and SF.

We need to build as fast as possible in order to start attracting workers to Downtown ASAP.

 

[Dirk_Birkin]

So what you're saying is that, for most of the length of the tunnel, we won't see very much disruption. And only the Downtown Station and 24th Street would see any tunneling actions?

If that's the case, then I don't understand the hubbub over this whole thing? The Rapid Bus caused a lot of issues because it was done at surface level, I believe?

Honestly, let's just get the damn thing going. Sitting here fiddling back and forth just waste more time and make the cost rise higher. For the next 10 years the Berryessa station is going to continue shipping workers off to the East Bay, rendering that neighborhood a bedroom community for Oakland and SF.

We need to build as fast as possible in order to start attracting workers to Downtown ASAP.

fwik, yes. the only surface disruption for the majority of the 6 mile tunnel will be air vents between the stations. with the twin bore option, this is essentially what the completed station will look like, a concrete box in the ground with a mezzanine just below ground level but with a center platform used for both trains:

after entering the station box, the TBM's will be moved through the box with cranes and start digging tunnels again on the other side:

once the machine is moved through the box, the box can be covered while construction on the station proceeds below grade.

according to vta, they can complete this task in 240 days at the downtown location. the alum rock station is north of santa clara street, and the southern option at diridon wouldn't require ripping up any of santa clara street.

 

[dirt patch]

Apparently, The Graduate on Second st. flops. They couldn’t close financing in the last minute. The site sits forlorn as expected.

 

[jpk122s]

fwik, yes. the only surface disruption for the majority of the 6 mile tunnel will be air vents between the stations.

In addition to the air vents, the twin bore tunnel needs regular cross passages to be mined between the two tunnels, which needs soil stabilizing grout injections from the surface. Also, the shallower twin tunnels will require utility relocation, even where there are no stations or vents.

Expect Santa Clara St. to be in various stages of dug up for at least 3 years. For an example of what this looks like, take a look at Stockton St. in SF near Union Square which has been dug up for the Central Subway station there for at least 3 years.

If we are lucky, the VTA light rail line will only be shut down for a year, but expect Santa Clara St. to be an impassable construction zone for much longer than that.

 

[Sharkcity]

fwik, yes. the only surface disruption for the majority of the 6 mile tunnel will be air vents between the stations. with the twin bore option, this is essentially what the completed station will look like, a concrete box in the ground with a mezzanine just below ground level but with a center platform used for both trains:

after entering the station box, the TBM's will be moved through the box with cranes and start digging tunnels again on the other side:

once the machine is moved through the box, the box can be covered while construction on the station proceeds below grade.

according to vta, they can complete this task in 240 days at the downtown location. the alum rock station is north of santa clara street, and the southern option at diridon wouldn't require ripping up any of santa clara street.

For a point of reference, excavation of the Union Square station in San Francisco began around January 2015 and is just now nearing completion = ~3 years of surface road disruption. 3 blocks of Stockton street from market to Post street have been out of use during this period (partly for staging which Mitchell block might alleviate). Even when work is mostly proceeding underground, the construction still affects the sidewalks and streets with construction fences, detours, lost travel lanes and parking spaces.

This graphic for the Purple-line under Wilshire in LA can help visualize the construction timeline. VTA/BART might say 240 days of surface activity, but Santa Clara will basically be disturbed for the majority of the project. There use to be an animation of the process w/ steel plates supporting the temporary road, but it looks to be taken down. Link
"LA Curbed: Purple-line subway timeline"

Heres an image of the Purple Line construction on Wilshire. Link

 

[bobby_guz_man]

It's time to get it done. We've been dicking around for more than a year while the cost rises and Berryessa has put in its application for East Bay suburb status.

 

[quadshock]

Developer proposes project with charter school, affordable housing for San Jose ‘urban village’

SVBJ link

The city of San Jose has received plans for a mixed-use development within its Alum Rock Urban Village that would include a charter school and 94 affordable housing units — marking a first-of-its-kind proposal for the city.

“The point of urban villages is to put a mix of uses close together,” said San Jose land-use consultant Erik Schoennauer. “The idea of having a school and multifamily housing integrated together on one site would be consistent with the goals of urban mixed-use development.”

 

[sjn]

I am anti-charter school personally, but I have to say I like that a lot. That area needs more school options and it looks like the frontage focuses on the school part more than the apartments, which is a benefit to the students.

 

[pesto]

These really sum up why we're unlikely to see large-scale affordable projects.

Even if there was money to do these at a larger scale, we're hopefully past those top-down utopian idealizations of "helping" the poor by creating all-in-one complexes that one group thinks is everything the other group needs to be happy.

The rule of thumb from Brazilian studies: it takes 2 years for the residents of a brand new, modern large scale housing project to make it as dilapidated as the old place they lived in.

The lesson is change the PEOPLE don't change the HOUSING.

 

[pesto]

For a point of reference, excavation of the Union Square station in San Francisco began around January 2015 and is just now nearing completion = ~3 years of surface road disruption. 3 blocks of Stockton street from market to Post street have been out of use during this period (partly for staging which Mitchell block might alleviate). Even when work is mostly proceeding underground, the construction still affects the sidewalks and streets with construction fences, detours, lost travel lanes and parking spaces.

This graphic for the Purple-line under Wilshire in LA can help visualize the construction timeline. VTA/BART might say 240 days of surface activity, but Santa Clara will basically be disturbed for the majority of the project. There use to be an animation of the process w/ steel plates supporting the temporary road, but it looks to be taken down. [

Three years sounds too short if Wilshire is the example, but maybe Santa Clara is shorter than Western to La Cienega.

Areas near stations are closed for months at a time and larger sections are narrowed, have hand-sign controls and left turns blocked. Side streets get traffic dumped onto them. Around the stations means two complete city blocks (say, one or two blocks either side of Western or Fairfax) of complete blockage, sometimes even for pedestrians. Traffic is dumped onto side streets. And when the plates are in place the ride slows to a crawl.

 

[pesto]

SVBJ link

This seems to be the trend. Large city schools are so bad that developers will dedicate space for charter schools to attract potential residents. I have seen this in proposals in NY, LA and smaller cities as well.

And, of course, the urban village idea is that there is privately controlled property that can actually maintain safety for residents and visitors, cleanliness, good repair and decent aesthetic standards.

 

[Xynoplas]

So the advantage of twin bore is...
(Somebody please stop me!)
Twice as boring!
(Too late.)

 

[usedmedia]

BART’s big dig leading to a big fight in Silicon Valley

“Basically there’s a standoff,” says one high-level transit source, speaking on condition of anonymity because the person needs to work with both sides. “The VTA is not going to build something it doesn’t want to build, and BART is not going to operate something it doesn’t want to operate.”

http://www.sfgate.com/bayarea/article/BART-s-big-dig-leading-to-a-big-fight-in-12375762.php?t=2b76f956ed

 

[Sharkcity]

Three years sounds too short if Wilshire is the example, but maybe Santa Clara is shorter than Western to La Cienega.

Areas near stations are closed for months at a time and larger sections are narrowed, have hand-sign controls and left turns blocked. Side streets get traffic dumped onto them. Around the stations means two complete city blocks (say, one or two blocks either side of Western or Fairfax) of complete blockage, sometimes even for pedestrians. Traffic is dumped onto side streets. And when the plates are in place the ride slows to a crawl.

3 years refers to the 1.7 mile SF central tunnel. The LA Wilshire work is 8-9 years of disruption along the 3.9 mile phase 1. VTA/BART plans 4 years of construction for 6 miles.

The LA project is slowed by the tar pit geology and extensive archeological work that must be done but basically Santa Clara will be a mess for a long time similar to other projects including BART's SF Market Street heart surgery in the 60s and VTA's SJ lightrail in the 90s. If twin bore is chosen, expect development downtown to slow down until the project completes. Google has already expressed a desire to wait due to the uncertainty of the single/twin bore.

Its sad that every urban tunnel project runs into the same issue. Alternatives to cut and cover are sought to minimize disruption but project managers shut it down due to schedule concerns and extra design work. Someone needs to innovate if we are to build more urban transit (maybe underground VTA Lightrail in DT and N 1st).

 

[Sharkcity]

http://www.sfgate.com/bayarea/article/BART-s-big-dig-leading-to-a-big-fight-in-12375762.php?t=2b76f956ed

“'When BART was constructed on downtown Market Street in San Francisco, it took two generations for the core of that city to recover,' San Jose Mayor Sam Liccardo said Tuesday."

 

[RaymondHood]

“'When BART was constructed on downtown Market Street in San Francisco, it took two generations for the core of that city to recover,' San Jose Mayor Sam Liccardo said Tuesday."

Does anyone know if this is true?
It sounds like a complete fabrication to me.
How long is a generation -- 25 years?
Two generations is longer than BART has been in existence.
And much of SF's downtown's disruption was caused by extensive urban renewal, including construction of a mega convention center, and by removal of an earthquake-damaged freeway.

 

[rickupton]

Does anyone know if this is true?
It sounds like a complete fabrication to me.
How long is a generation -- 25 years?
Two generations is longer than BART has been in existence.
And much of SF's downtown's disruption was caused by extensive urban renewal, including construction of a mega convention center, and by removal of an earthquake-damaged freeway.

From http://www.bart.gov/about/history/history

"In July, 1967, work began on the Market Street subway and stations 80-100 feet below heavy downtown traffic."

When was the "core" considered "recovered"?

 

[Davodd]

How long is a generation -- 25 years?

A generation is 20 years.

 

[quadshock]

I imagine Liccardo meant 2 economic cycles...