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Post by Gokhan on Jun 5, 2013 12:34:20 GMT -8
They finished the last support for the Venice Bridge last night and it's now wrapped up for curing -- about two weeks. There are still three comm cables remaining directly in the path of the bridge that must be removed before falsework installation can continue. If they are not removed in less than two weeks, the bridge construction will be delayed. Meanwhile they are pouring concrete for the foundation of the retaining wall of the Palms Station. Concrete trucks come from the plant at Exposition and Sepulveda Boulevards.
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Post by Gokhan on Jun 6, 2013 11:31:54 GMT -8
Alternate view of the Venice Bridge. Note the three communication cables in the way. I asked Rick about it yesterday and he said that they could build the bridge under them if necessary. Work is supposed to start in two weeks, once the forms for the last support can be peeled off: View toward the Palms Station. Balfour Beatty Infrastructure is still using the area behind Albertsons for staging. This is where the MSE ramp will go in, east of Durango Avenue:
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Post by roadtrainer on Jun 6, 2013 20:14:22 GMT -8
[ quote author="Gokhan" "]It's a reinforced-concrete "box structure" under the freeway, not really a tunnel.
The box structure is called "Palms Overhead".
Is there such a thing as a tail swing on a train when it is coming around a curve.....For those who don't know what a tail swing is I'll explain... a forty foot bus makes a right turn, during this turn the front of the bus makes a right, while the rear of the bus makes a left. One of the hardest things to get people to understand about school busses is the Tail Swing. The easiest way for me to explain it is to think of a teeter totter. On a teeter totter, when one side goes up, the other side must go down. Its the same with Tail Swing on a school bus, when the front end goes left, the back end must go right. Depending on the type of bus, the Tail Swing can be almost 2 feet. This is more than enough to hit something, or someone standing on the curb. So now you understand about a tail swing on a bus ..Is there a tail swing on a train going around a curve? The reason I ask is this Will the expoline train have a tail swing when it comes out of the tunnel under the 10 freeway?
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Post by Gokhan on Jun 6, 2013 22:19:30 GMT -8
[ quote author="Gokhan" "]It's a reinforced-concrete "box structure" under the freeway, not really a tunnel.
The box structure is called "Palms Overhead".
Is there such a thing as a tail swing on a train when it is coming around a curve.....For those who don't know what a tail swing is I'll explain... a forty foot bus makes a right turn, during this turn the front of the bus makes a right, while the rear of the bus makes a left. One of the hardest things to get people to understand about school busses is the Tail Swing. The easiest way for me to explain it is to think of a teeter totter. On a teeter totter, when one side goes up, the other side must go down. Its the same with Tail Swing on a school bus, when the front end goes left, the back end must go right. Depending on the type of bus, the Tail Swing can be almost 2 feet. This is more than enough to hit something, or someone standing on the curb. So now you understand about a tail swing on a bus ..Is there a tail swing on a train going around a curve? The reason I ask is this Will the expoline train have a tail swing when it comes out of the tunnel under the 10 freeway? Yes, trains have the so-called dynamic envelope, which is about 11 ft in width, as opposed to the 8.7 ft width of the LRVs. This was taken into account when they made the track design.
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Post by Gokhan on Jun 9, 2013 20:18:02 GMT -8
[ quote author="Gokhan" "]It's a reinforced-concrete "box structure" under the freeway, not really a tunnel.
The box structure is called "Palms Overhead".
Is there such a thing as a tail swing on a train when it is coming around a curve.....For those who don't know what a tail swing is I'll explain... a forty foot bus makes a right turn, during this turn the front of the bus makes a right, while the rear of the bus makes a left. One of the hardest things to get people to understand about school busses is the Tail Swing. The easiest way for me to explain it is to think of a teeter totter. On a teeter totter, when one side goes up, the other side must go down. Its the same with Tail Swing on a school bus, when the front end goes left, the back end must go right. Depending on the type of bus, the Tail Swing can be almost 2 feet. This is more than enough to hit something, or someone standing on the curb. So now you understand about a tail swing on a bus ..Is there a tail swing on a train going around a curve? The reason I ask is this Will the expoline train have a tail swing when it comes out of the tunnel under the 10 freeway? Yes, trains have the so-called dynamic envelope, which is about 11 ft in width, as opposed to the 8.7 ft width of the LRVs. This was taken into account when they made the track design. I had posted this CPUC drawing earlier. The LRVs have 8.7 ft cross-sectional width but their dynamic envelope is much wider. They gave 11.4 ft of space for them in the tunnel, but as you see in the drawing, this is barely enough and there is absolutely zero clearance between the walls and the trains will occasionally scrape the walls. Note that there is a 2 ft 8 in walkway in the middle -- barely enough for an average-size person to squeeze in. Although, you would be doomed if you had wide hips and/or broad shoulders. The speed limit in the tunnel will be 25 MPH. So, yes, it will be the "Tunnel of Horror".
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Post by bobdavis on Jun 9, 2013 23:26:33 GMT -8
Regarding "tail swing": Going back into history, the old LA Railway cars had their trucks fairly close to the ends--one advantage of the narrow gauge. When LARy bought their two experimental "Type M" cars (2601-2602) in 1929-30, these had the trucks closer to the center, and the company wound up assigning them to the "7" line, which had very few curves. When Pacific Electric acquired the "blimps" from Northwestern Pacific and the SP East Bay suburban operations, they had to move the couplers further out and restrict the big cars from passing each other on certain curves. The "blimps" were designed for steam-railroad tracks, not streetcar lines.
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Post by Alexis Kasperavičius on Jun 10, 2013 5:03:49 GMT -8
Considering the tunnel has been a huge canvas and right-of-passage for street taggers - known as "Motor Yard" - since the 1970's, I am concerned that some kids will attempt to get in there for old time's sake - perhaps late one night after a bender.
They've already tagged the National and Motor bridge construction areas, and they are still actively tagging the inside of the tunnel.
The tunnel will be cleaned, but they'll come back. The trains will start running and they'll come back.
With no clearance, there will be some close calls. Those trains are quiet. If they're drunk or high at the same time, this could be tragic.
Note that this video was posted after construction started:
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Post by culvercitylocke on Jun 10, 2013 9:02:19 GMT -8
Yes, it's pretty much inevitable that some taggers/kids will be killed by an expo train in the tunnel, probably during non-revenue service testing because they'll think it is still safe. This will delay implementation of the revenue service as NFSR tries to get the expo line permanently blocked from using the box structure/tunnel unless it is expanded/replaced.
So we'll probably start Revenue service to Palms in 2016, have two-three years of replacing the box structure because 'think of the children!' and open revenue service to Santa Monica sometime in 2020 or 2021.
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Post by Philip on Jun 10, 2013 10:24:57 GMT -8
Don't give them any ideas.
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Post by Gokhan on Jun 10, 2013 12:29:05 GMT -8
It will be very difficult to access the area once it's fenced. They would have to walk from Overland/Exposition or the Palms Station.
There will also be an intrusion-detection system in the tunnel.
I do see a lot of graffiti in the Northvale Road trench construction area. They should really put a guard there.
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Post by Gokhan on Jun 10, 2013 12:33:18 GMT -8
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Post by Gokhan on Jun 10, 2013 15:56:25 GMT -8
Major Issues Delay to Venice Boulevard Bridge Substantial Completion: Staff, the bridge contractor (BBII) and SRJV have developed workarounds that should support completion of the overall project within schedule. Staff and BBII are negotiating a final completion date and the segregation of cost responsibilities associated with the delay Potential delays due to SCE utility relocations: • Overhead relocations required at Sepulveda Blvd and Bundy Drive • Underground relocations required along Colorado Avenue̶ Working with SRJV and the City of Santa Monica to accelerate duct bank installation ̶ Working with SCE to begin infrastructure installation in parallel with duct bank installation to reduce schedule risk Third party scope growth Delay in California Public Utilities Commission (CPUC) approval of rail crossingsFrom project update
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Post by Alexis Kasperavičius on Jun 11, 2013 7:36:45 GMT -8
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Post by Gokhan on Jun 12, 2013 13:26:23 GMT -8
Balfour Beatty Infrastucture is still waiting for their last support to cure -- probably about another week -- before they get started on the bridge, despite the overhead cables being gone.
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Post by culvercitylocke on Jun 12, 2013 15:42:30 GMT -8
If you hover on the calendar at www.expovenice.org/construction/ you see a popup that says what the plan is for that day's construction. Falsework continues over/around Robertson this week, EB Venice closes next week for falsework install, and WB Venice closes the week after that for falsework install.
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Post by culvercitylocke on Jun 13, 2013 8:59:46 GMT -8
Steel spanning Robertson for the westbound track went up overnight.
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Post by culvercitylocke on Jun 14, 2013 9:49:30 GMT -8
and now we have steel spanning robertson for the eastbound track and has reached bent 17. Steel should go up over Eastbound Venice next week.
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Post by Gokhan on Jun 14, 2013 11:02:26 GMT -8
Latest status of the Venice Bridge. Note that the furthest column is still curing and wrapped up. Therefore, they can't extend the falsework over Venice Blvd median for the eastbound track until it's unwrapped:
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Post by Alexis Kasperavičius on Jun 15, 2013 5:21:44 GMT -8
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Post by rubbertoe on Jun 15, 2013 6:43:25 GMT -8
One of the things that will make the Venice structure get done a bit faster than some others is that it is going to be two separate bridges, not a single massive structure. That should decrease the amount of falsework, rebar, concrete, etc. Makes sense too cause coming off the current terminus the tracks are already pretty far apart, and there is no need for there to be a single structure like the Olympic/Cloverfield monstrosity...
RT
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Post by rubbertoe on Jun 15, 2013 6:56:33 GMT -8
Looking at Dwight's pictures there is another thing I just don't get. Some of the MSE walls are cast in place. They build a concrete footing, then throw up a ~8" thick rebar structure, and then put up two large panels with a single support. Pour the concrete in and you have a permanent wall for the side of the MSE, like this: Then you have the other method, where they take what seems to be like weeks to assemble a patchwork of pre-cast squares. These take so much longer, and then I wonder about the seismic effect on one of these walls versus a cast in place wall: Any construction engineers out there care to speculate how the latter method provides any better wall than the former from either a cost, safety, or time saving perspective? RT
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Post by Gokhan on Jun 15, 2013 8:21:04 GMT -8
Looking at Dwight's pictures there is another thing I just don't get. Some of the MSE walls are cast in place. They build a concrete footing, then throw up a ~8" thick rebar structure, and then put up two large panels with a single support. Pour the concrete in and you have a permanent wall for the side of the MSE, like this: Then you have the other method, where they take what seems to be like weeks to assemble a patchwork of pre-cast squares. These take so much longer, and then I wonder about the seismic effect on one of these walls versus a cast in place wall: Any construction engineers out there care to speculate how the latter method provides any better wall than the former from either a cost, safety, or time saving perspective? RT No, actually the second method (many prefabricated panels), which is the preferred method, is cheaper and faster. The reason why it appears slow is because they are doing the backfilling as they build the wall. In the first (cast-in-place) method, they need to do the backfilling afterwards. They have been working on the Palms cast-in-place walls for many months now. However, in order to use the second method, you need two walls facing each other, as the opposing panels are held together with wire meshes attached to the hooks at the back of them that span from side to side. There are many layers of them, compacted inside the backfilling gravel layer by layer. In places like Palms, where they can only fit one wall on one side as the other side is not accessible, you have no option other than to have a single cast-in-place wall. You then backfill it later.
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Post by roadtrainer on Jun 15, 2013 11:24:58 GMT -8
Personally I like the first wall and not the building blocks type.
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Post by davebowman on Jun 17, 2013 9:52:49 GMT -8
This morning there was concrete being poured at the east end of the Cloverfield/Olympic bridge.
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Post by bzcat on Jun 17, 2013 11:28:25 GMT -8
There are rebars sticking out of the ground on the ROW between Overland and Westwood. Looks like the beginning of sound wall construction. I thought there was just a fence here and no wall?
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Post by Gokhan on Jun 17, 2013 12:50:41 GMT -8
There are rebars sticking out of the ground on the ROW between Overland and Westwood. Looks like the beginning of sound wall construction. I thought there was just a fence here and no wall? Sound-wall frames have already been constructed there. (Yes, there will be sound walls.) Not sure what you saw was. Perhaps the communications building at the end of the platform or the platform itself.
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Post by Gokhan on Jun 17, 2013 12:53:44 GMT -8
Personally I like the first wall and not the building blocks type. The cast-in-place wall is the only choice when there is a single wall, like in Palms. When there are two opposing walls, small blocks that are pulled together in place by wires across the right-of-way can be used. They should both look similar at the end. However, cast-in-place will look slightly better because you have more control during construction.
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Post by Gokhan on Jun 17, 2013 13:31:32 GMT -8
Glass sound walls by I-405 near Sunset Blvd. it would be so nice if they used these for the Expo Line:
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Post by darrell on Jun 17, 2013 14:37:42 GMT -8
Looking at Dwight's pictures there is another thing I just don't get. Some of the MSE walls are cast in place. They build a concrete footing, then throw up a ~8" thick rebar structure, and then put up two large panels with a single support. Pour the concrete in and you have a permanent wall for the side of the MSE, like this: Then you have the other method, where they take what seems to be like weeks to assemble a patchwork of pre-cast squares. These take so much longer, and then I wonder about the seismic effect on one of these walls versus a cast in place wall: Any construction engineers out there care to speculate how the latter method provides any better wall than the former from either a cost, safety, or time saving perspective? RT No, actually the second method (many prefabricated panels), which is the preferred method, is cheaper and faster. The reason why it appears slow is because they are doing the backfilling as they build the wall. In the first (cast-in-place) method, they need to do the backfilling afterwards. They have been working on the Palms cast-in-place walls for many months now. However, in order to use the second method, you need two walls facing each other, as the opposing panels are held together with wire meshes attached to the hooks at the back of them that span from side to side. There are many layers of them, compacted inside the backfilling gravel layer by layer. In places like Palms, where they can only fit one wall on one side as the other side is not accessible, you have no option other than to have a single cast-in-place wall. You then backfill it later. Here are some 2009 Phase 1 construction photos that show how the MSE wall panels are tied into the earth with metal grids: La Brea panels, showing the U-shaped attachemnts and tongue-and-groove edges. The small footing the MSE wall panels will rest on. A load of grids that tie the wall panels into the compacted earth fill. I never noticed any ties from the grids on one side to the other. Back side of the west La Brea abutment showing the first row of wall panels on their foundation. Cast-in-place cap and slab is now above the MSE wall west of La Brea. Beginning of the La Cienega walls, east of the bridge. Nearly finished with the fill west of La Cienega.
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Post by joemagruder on Jun 17, 2013 20:16:49 GMT -8
I keep wondering what the lifespan of the grids is and what happens when they become iron oxide.
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