Chilean Bridges: INACAP POC

A few blocks further north and we come to another footbridge carrying students from a bus stop to a technical university.

This area between Concepcion and Talcahuano is growing rapidly. My Chilean hosts say that Chile is becoming the wealthiest country in South America. However, there are very mixed feelings about the role the military played in this development. People were uncomfortable seeing the army back on the streets after the recent earthquake.

This POC is an interesting kind of truss that I haven't seen before. It is composed of six 'V's carrying forces between the top and bottom chords with large spaces in between. It has an eccentrically placed single-column bent on the right side of the truss. However, the bottom chord is quite beefy and the truss may be playing a secondary role (carrying the roof).

The two ends of the POC are supported by handsome brick structures that also support the ramps running parallel to the road. It looks like there is a shelter on the first story of these masonry structures. Although the POC isn't terribly exciting, it indicates the city's efforts to provide something more architecturally pleasing through this new commercial district.

Chilean Bridges: INACAP POC by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: Pasarela Plaza Del Trebol

Another footbridge, this one carrying people from the mall over Talcahuana Way to a bus stop. I guess this structure can best be described as utilitarian. It certainly gets a lot of use.

We went to the food court in the mall for lunch. It had a huge dining area, and it was packed on a Wednesday afternoon. While we were eating, a big aftershock started shaking the mall. All the talking stopped and you could hear a pin drop. It looked like the crowd was ready to panic, but thankfully the shaking gradually subsided.

This bridge is a kind of tubular truss structure supported on four-legged towers, and enclosed in translucent plastic. This type of structure has become very popular lately and it has an interesting appearance although I don't think of it as structurally significant.

Pedestrian Overcrossings are vary common throughout Chile and are a good away of keeping people and automobiles away from each other.

Chilean Bridges: Pasarela Plaza Del Trebol by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: Pasarela Sobre Autopista Costanera

This fancy pedestrian overcrossing is also near the Rio Biobio, but on the east side near Puente Llacolen. One side of the bridge can be accessed by a kind of stairwell while the other side is connected to a long ramp.

Although this POC is a little overdecorated, I think it blends in well with the brightly-colored apartments and the pretty park.

Chilean Bridges: Pasarela Sobre Autopista Costanera by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: Pasarela Peatonal sobre la Autopista Alessandri

Another pedestrian overcrossing in Concepcion, Chile. It is just northwest of Puente Juan Pablo II over the Rio Bio Bio.

This is a simple Warren through truss with a arched top chord. It looks like a pony truss, which means that it doesn't have a portal frame or any cross bracing on the top.

Chilean Bridges: Pasarela Peatonal sobre la Autopista Alessandri by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: Concepcion Arch POC

Engineers get a chance to be a little more creative when designing pedestrian bridges, especially in Chile. We've discussed how our aesthetic experience for bridges is related to seeing how the structure performs. This is one of the clearest illustrations for a three-pinned arch in recent memory. I like how clearly articulated the pins are and how the deck sits on the two arch ribs.

There's a series of these interesting pedestrian structures on the highways near Plaza Del Trebol, the big shopping mall on the north side of town.

Chilean Bridges: Concepcion Arch POC by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: Puente Ferroviario de Lontué

Another railroad bridge viewed from the side of Route 5 Sur in Chile. The railroad bridge (along with the adjacent highway bridges) was damaged by flooding of the Rio Lontué in 2008, effectively dividing the country in two. The railroad bridge looks the same so they must have been able to pick it up and set it back on it's piers.

Charles Darwin also writes about the Rio Lontué in his journals and speculates that an earthquake in 1762 caused a landslide and dam across the Rio Lontue. The water eventually burst through spreading boulders throughout the area. This may be the first description of debris dams that continue to cause damage following earthquakes. He further speculates that such debris can now be found atop mountains suggesting that parts of Chile have been uplifted over time.

The Puente Ferroviario de Lontué is a three span through truss. The end spans have a curved top chord while the center span has a straight top chord, which seems to be a common arrangement.

Chilean Bridges: Puente Ferroviario de Lontué by Mark Yashinsky is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.

Chilean Bridges: Puente de Tinguiririca

The Tinguiririca River is famous for its whitewater rapids and because a plane carrying rugby players once crashed into its source on the Tinguiririca Glacier in the Andes.

The Tinguiririca Bridge is a railroad bridge (on the west side of Route 5 Sur in Chile). In this photo we are looking at the bridge between the barrier rails of the adjacent highway. A variety of lifelines including gas, water, railway, and highway often conveniently share the same right-of-way (at least until one of them starts having problems that impacts the others).

This is a through truss bridge and I believe it's a Pratt truss because the diagonal elements slope downward towards the middle of the bridge. It is a three span bridge with catenary elements to hold the electric line that powers the locomotive.

Chilean Bridges: Puente de Tinguiririca by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: El Puente Ferroviario de Longaví

Continuing our tour of railroad bridges in Chile, we come to another Warren truss that had some damage during last month's earthquake. This photo was taken in the early morning and so the bridge is shrouded in fog. Although you cannot tell, this bridge is back on the east side of the Pan American Highway (Route 5). I don't really understand why, but the railroad moves back and forth under Route 5 many times between Concepcion and Santiago.

I am wondering whether the span falling is related to lateral spreading of the river bank (on the far right side of the photo). You can see that the truss has moved to the north, pushing the next span off of it's support. However, it could just as well have been caused by ground shaking. Also, it's hard to tell, but the pier just north of the dropped truss looks like the legs have moved apart. Since I don't see a cap at the top of the columns, I think it's possible. One thing is for sure, the depth of the truss stopped the span from falling to the ground. It looks like it got wedged against the adjacent protruding truss. If this had been a girder bridge, it would have fallen as soon as it was pushed off the pier.

Chilean Bridges: El Puente Ferroviario de Longaví by Mark Yashinsky is licensed under a Creative Commons Attribution-No Derivative Works 3.0 United States License.

Chilean Bridges: Puente Ferroviario del Río Bio Bio

Another railroad bridge, this one crossing the 2.2 km wide Rio Bio Bio in Concepcion, Chile. The river flows through the second largest city in Chile, and yet there is almost no development along it's banks. The Rio Bio Bio is incredibly wide and it must be a tidal estuary flowing into the sea near Conception.

This railroad structure is composed of parallel top and bottom chords separated by diagonal and vertical members in a Warren truss arrangement. Note the overhead wire and catenary that is used to power the train.

This bridge as well as all the other bridges across the Rio Bio Bio in Concepcion were damaged by last month's earthquake due to strong shaking and lateral spreading of the river banks.

Chilean Bridges: Puente Ferroviario del Río Bio Bio by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: Viaducto del Malleco

The Malleco Viaduct was the tallest railroad bridge in Chile when it opened in 1890. It runs parallel to the PanAmerican Highway (Route 5) in South-Central Chile. Apparently Gustave Eiffel made a proposal to design the bridge, but his proposal was rejected and the design went to Aurilio Lasterria.  It's an interesting lattice truss with fillets connecting the superstructure to the towers.

The railroad runs parallel to the highway for much of the length of Chile. Note that the train is powered by a cable suspended above the tracks. It would seem that the railroad would be an ideal transportation solution for a long, skinny country like Chile, but it is barely used (similar to the US). After the earthquake, the railroad was utilized to remove building debris.

Chilean Bridges: Viaduct Malleco by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: Puente Padre Letelier

Santiago is a pretty city that was founded in 1541. Most cities have parks along their rivers and Santiago has Parque Forestal along the Rio Mapocha.

The Puente Padre Letelier is just a precast I girder bridge, but it has lovely sculptures mounted on the exterior girders.
- Posted using BlogPress from my iPhone

Location:Chile

Chilean Bridges: Puente Rio Claro

There are three handsome arch bridges across the Rio Claro in Central Chile. In the photo is northbound Route 5, a new deck arch. There is also a steel railway bridge to the east and a beautiful multispan masonry arch that was used for southbound traffic that collapsed during the M8.8 earthquake.

- Posted using BlogPress from my iPhone

Location:Chile

Chilean Bridges: Carahue Railroad Bridge

Next to the pedestrian bridge in Carahue is a very long railroad viaduct that ends in a steel through truss over the Imperial River.

The railways seem to be having a hard time in Chile. This bridge doesn't appear to be used, and repairs to rails doesn't seem to be going on as quickly as repair of toll roads.

Most of the tracks have a cantilever for providing electricity to power the locomotive.

- Posted using BlogPress from my iPhone

Location:Av Pedro de Valdivia,Santiago,Chile

Chilean Bridges: Puente Tranapuente

About ten miles west of the Carahue POC is this handsome bridge over the Imperial River near the coast. It's an 800 ft long steel girder bridge on battered two column piers. Rodrigo tells me that steel girder bridges are unusual in Chile.

The Tranapuente Bridge has two 400 ft long continuous spans. It experienced moderate movement of the girders and damage to keeper plates and abutments from the earthquake.





- Posted using BlogPress from my iPhone

Location:Chile

Chilean Bridges: Carahue POC

A photo of my bridge team on the Carahue POC (Scott, Luis, and Rodrigo). We're spending the rest of the week working our way back to Santiago. Tonight we are in Conception, which had a lot of bridge damage from last month's earthquake.






- Posted using BlogPress from my iPhone

Location:Chile

Chilean Bridges: President Frei Bridge

We drove today from Santiago almost 700 km south as we began studying bridge damage from the February 27th (M8.8) earthquake (I felt a small aftershock as I wrote this sentence).

Surprisingly, there is a suspension bridge (as well as many old steam powered tractors) in Carahue Chile. The bridge was named after President Frei of Chile and it crosses the broad Imperial River.






- Posted using BlogPress from my iPhone

Great Britain: Firth of Forth bridge

My plane had trouble taking off (bad generator) and landing (earthquake damage). My friend who flew on American Airlines arrived in Santiago at the same time as me although he took off (from Texas) six hours later than I did.

I had meetings all day and now I'm exhausted from two days of travel. I wanted to put a bridge photo from Chile on my blog but it will have to wait until tomorrow.

In the meantime, enjoy this view of the Firth of Forth Bridge in Scotland, maybe the most beautiful bridge in the world.

- Posted using BlogPress from my iPhone

Great Britain: North Parade Bridge (2)

My last photo of Bath is a view of the approach onto the North Parade Bridge over the River Avon. This is a handsome single span stone masonry arch bridge The original bridge was built in 1836 of cast iron with stone abutments. It was rebuilt in 1936 completely in stone.

The Tall Bridge Guy likes it when I travel to new and exotic places to photograph bridges. Today I'm flying to Chile (as part of the PEER, EERI, FHWA Investigation Team) to collect data on the performance of bridges during the February 27, 2010 Maule, Chile Earthquake.

Hopefully, I'll have time to send a quick blog from the field every day.

Great Britain: North Parade Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: North Parade Bridge (1)

I don't often provide a view of a bridge deck in my blog. We're back to where I took the first photo (of Pulteney Bridge) for the recent blogs about bridges in the ancient city of Bath.

The older bridges in Bath have a nice architectural presence with their carefully mortared stones, ornamental lamps, building-like edifices, etc. The view of the tower of Bath Abbey also adds to the experience.

Bridge engineers don't have to be architect's adversary. In most of my work, I'm working to make the architect's vision a reality. I particularly like the Piranesi-like quality of this bridge deck.

Great Britain: North Parade Bridge (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Sainsbury Bridges (3)

A look back at Sainsbury's Pedestrian Bridge.  A plastic roof was mounted to the concrete barrier rails. It must be pleasant to seek shelter under the barrel-shaped surface on a rainy day. However, I'm not sure if I like bridges made out of short-lived materials. Also, the concrete pedestal attached to the much older stone pier gives the bridge a temporary appearance.

Great Britain: Sainsbury's Bridges (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Sainsbury Bridges (2)

A look under the two Sainsbury's Bridges.

The bridge on the left looks like the Midland Road Bridge with it's big bottom chords supporting tapered floor beams. This is more evidence that the two bridges used to sit side by side.

Instead of big steel rocker bearings that support the bridge on the left, the bridge on the right sits directly on a reinforced concrete pedestal. Also one of the girders on the pedestrian bridge looks like it was struck by a passing vessel. This seems strange since the  bridge on the left wasn't hit.

Great Britain: Sainsbury's Bridges (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Sainsbury Bridges (1)

Continuing on our walk along the River Avon to Bath, we arrived at Sainsbury's Bridges. I wish they wouldn't put two different bridges next to each other because it's hard to distinguish each bridge's features. For instance, in this photo, it looks like the bridge in front has a plastic roof, when it's actually on the other bridge.

The structure in front was a railroad bridge that was converted for highway use after the trains stopped running. I would have called it some kind of lattice truss, except they usually have a roof. Maybe the roof was removed when the bridge was converted to vehicular traffic. The bridge is a two-span steel through truss structure supported at midspan on a large stone pier with cutwaters and on seat-type abutments. Note the big rocker bearings supporting the truss.

Since these bridges provide access to the Green Park Railway Station, I wonder if the pier was the former location of the Midland Road Bridge? The strange thing is that we don't see any sign of where a pier might have been attached to the Midland Road Bridge (in yesterday's photo). Also, it's apparent that the Midland Road Bridge doesn't need a support at midspan. However, there is quite a bit of room on the existing pier where another bridge may have stood.

The other Sainsbury's Bridge is a footbridge supported on three precast I girders. We'll take another look at both these bridges tomorrow.

Great Britain: Sainsbury's Bridges (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Midland Road Bridge (2)

Returning to Bath on the footpath along the River Avon, we get an interesting view of the underside of the Midland Road Bridge. We can see the bottom chord of the truss supporting the floor beams that hold up the deck. You can also see the thousands of rivets used to build the floor beams and the bottom chords.

The underside of the bridge is surprisingly clean with just a few rust spots on the soffit. Since the bridge was most probably built before WWII, I would guess it has been rehabilitated.

I found an article on the internet (by someone with the poetic name of Pierre Terre), who said the Midland Road Bridge had been moved from its original location at the Bath Green Park Railway Station. Most likely the bridge was cleaned during the move. Note the use of soldier piles for a quay wall under the bridge. Perhaps the river was wider at it's former location because you can't even see the north bridge abutment behind the heavy shrubbery.

Unlike the underside of many bridges, the underside of this bridge clearly shows how the load is carried.  The beefy, bottom chords not only acts in tension, but they also carrying the floor beams through shear and moment. I like how the floor beams are haunched to better carry the positive moment (and to allow room for the chords). I wonder if the bridge was used to carry trains at its former location?

Great Britain: Midland Road Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Windsor Bridges (2)

The Windsor Bridges were as far as I walked along the River Avon. I often regret not going a little further, because there is usually a beautiful bridge just ahead. That was true in this case as a gorgeous stone arch bridge carrying A4 across the River Avon was a mile downstream and the amazing Clifton Suspension Bridge is 12 miles downstream.

In this photo we are looking back upstream at the Windsor Bridges and the Gasworks Siding Bridge. The Gasworks are visible on the right bank. It looks like the metal frame around the tank supports it as it rises and falls. I understand that two of the three gas tanks have now been removed.

The Whipple truss (on the closer Windsor Bridge) was considered innovative because the diagonal members crossed two panels. In fact, it is sometimes called a double-intersection Pratt truss. It's not obvious (to me anyway) why this bridge is stronger other than more diagonals means more load carrying capacity. The symmetric arrangement of diagonal members must be popular because the Midland Road Bridge also has them. The Windsor Bridge has a single span of about 200 ft so it's pretty strong. This design was used to carry steam locomotives. I couldn't find much information on this bridge but it looks like an older (maybe 19th century) bridge that was in use when the Gas Works were an important part of the local economy.

Since I never made it farther downstream along the locks to Bristol Channel, we'll turn around tomorrow and revisit a few bridges on our way back to Bath.

Great Britain: Windsor Bridges (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Windsor Bridges

Continuing downstream on the River Avon we come to the two Windsor Bridges. We can see a little bit of the Windsor Road Bridge on the top left corner of the photo. Because of what looks like a sloping exterior girder, I'm guessing that it's a single span, reinforced concrete box girder bridge.  I also know (from Google Earth) that it's a wide bridge with standing vehicles waiting to turn left onto the A4, the Upper Bristol Road.

The other Windsor Bridge must have interested me more (since all my photos are of it). It looks like a utility bridge since it's loaded with cast iron pipes. It's a little bit like the Victoria Bridge because it has diagonal members that slope downward towards midspan where they cross each other. Also it has rods coming down from the deck, supporting the floor beams. And the bottom chord looks like a reinforced concrete beam (?) that matches the concrete abutments. The top chord is curved like an truss arch bridge. It has the same decorative cross and portal braces as the Midland Road Bridge. After looking at the Bridge Spotter's Website, I believe it's a Whipple bowstring truss, in which case the heavy bottom chord would be the bowstring. The website said this design was patented in 1847 by Squire Whipple as a longer, stronger version of the Pratt truss.

Looking downstream we can see the Midland Railroad Bridge, a two-span steel through girder structure. However it hasn't carried a train since 1973 (unless an agreement has been reached to use it as a rapid transit link for Avon Metro). Further in the background are rows of houses along the undulating hillside. This is the town of Twerton. If we continued further downstream, we would come to the Weston Locks from when barges used to carry goods between Bristol and Bath.

Great Britain: Windsor Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Gasworks Siding Bridge

About 600 ft downstream from the Midland Road Bridge (shown in background) is the Gasworks Siding Bridge. It is a two span steel, through girder bridge across the River Avon. It's only interesting feature is the two-column bent with decorated capitals that supports the bridge at midspan.

This bridge once carried a railroad siding and still carries a 12 inch pipe into the gasworks. In the Google Earth photo below you can see the small tank farm (south of the river), the two Windsor Bridges, the Gasworks Siding Bridge, and the Midland Road Bridge.

Great Britain: Gasworks Siding Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Midland Road Bridge (1)

About 1000 ft downstream from the Victoria Bridge is the Midland Road Bridge. This single span through truss doesn't have any vertical members, just a series of X's. The cross-bracing and portal bracing are attached to the top flange of the top chord for a little extra vertical clearance.

The Midland Road Bridge has two vehicle lanes and sidewalks. It crosses the River Avon without any skew and it's about 175 ft long. I couldn't find any information about when this bridge was built or who designed it. I looked on the Internet, but all I discovered was that there was some confusion between this bridge and the nearby Midland Bridge Road Bridge, which is understandable.

Great Britain: Midland Road Bridge (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Victoria Bridge (3)

A photo of my wife and son standing in front of Victoria Bridge. The designer, James Dredge never became an influential bridge engineer, despite his innovative bridge designs.

Victoria Bridge (in Dredge's hometown of Bath) was his first bridge. He was a shareholder in the company that built it and they charged a toll of half a penny to cross it. The bridge weathered a powerful storm while it was being built which gave people confidence in it. It cost 1760 Pounds (in 1836) to build, it was turned into a public bridge in 1929, it was converted to a footbridge in 1946, and it's still in use.

The drawing above (from D. McQuillan's paper, From brewer to bridge builder: reflections on the life and work of James Dredge) shows one advantage of Dredge's 'Taper Principle.' A regular suspension bridge (on top) would collapse if you cut the cable in two but the Dredge bridge (at bottom) would remain supported if the suspension chain was cut in half.

I wonder if a modern steel suspension bridge was ever built using Dredge's 'Taper Principle?'

Great Britain: Victoria Bridge (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.