New Zealand's Bridges: Horotane Overbridges in Christchurch (1)

March 2011 (-43.573 Degrees, 172.695 Degrees) Horotane Overbridges

Next to the Port Hills Bridges are a pair of simple span precast I girder bridges on tall hammerhead bents. The columns are tall because the road is coming down from the mountains. This made the embankments too steep (in the view of the geotechnical engineer in our group) and resulted in slope stabilty failures. Very little bridge damage, though. We observed horizontal cracks on the sides of the columns facing the street (see drawing).

We'll take another look at this bridge tomorrow.  

New Zealand's Bridges: Horotane Overbridges in Christchurch (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

New Zealand's Bridges: New Waimakariri Bridges in Christchurch

March 2011 (-43.414 Degrees, 172.646 Degrees) New Waimakariri Bridge
   

The Waimakariri River is quite a way south of this photo. Perhaps the owners of the Christchurch Northern Motorway wanted to provide the smallest possible grade for their bridges. Or maybe it was essential to provide a couple of roads north of the river. A braided river constantly regrades its path to the sea (as it drops sediment along its path). Perhaps long bridges were necessary over a river that periodically changes its channel.

The new Waimakariri River Bridges are precast I girder bridges on pier walls with very long bent caps. Perhaps the extra large caps are to accommodate a bridge widening at some future date?

New Zealand's Bridges: New Waimakariri Bridges in Christchurch by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Mexico's Bridges: Puente Rio Armeria (2)

Its surprising how different a bridge looks from the deck. One would hardly notice  crossing a bridge over a river from the road. I guess a bridge always has two aspects, one from above the deck and another from below the deck.

For some reason, this bridge has two sidewalks although they don't continue onto the adjacent roadway. Maybe the sidewalk allowed the designer to use a vertical barrier rail instead of the New Jersey barrier used on US bridges.  These barriers are shaped to push errant vehicles back onto the road.

The sidewalk and rail have expansion joints to allow each span to expand and contract. Note the end of the rail has black and white stripes and the sidewalk curb is painted yellow. Apparently the Mexican Highway Department uses paint rather than protective devices to prevent injuries to distracted drivers.

Mexico's Bridges: Puente Rio Armeria (2)  by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Puente Rio Armeria (1)

Highway 8 connects the City of Colima to the City of Minatitlan. This road crosses over the ubiquitous Rio Armeria on a four span precast I-girder bridge with stone masonry pier walls and abutments. The deck is supported by five I-girders and has expansion joints at the end of each span, despite being covered in asphalt. Tiny shear keys sit on the inside of the exterior girders. A diaphragm holds the girders together and the little shear keys are meant to prevent the superstructure from moving off the wall during earthquakes. It looks like the girders sit directly on the wall although there might be a thin sill plate between them.

Mexico's Bridges: Puente Rio Armeria (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Puente Cuatro Caminos (2)

This bridge is near the intersection of roads going to Tuxpan, Ciudad Guzman, Tecalitlan, and Colima, hence the name Cuatro Caminos.

Puente Cuatro Caminos has three precast I-girder spans and short slab end spans. I wonder why they needed the little end spans?

It looks like the girders and the deck are simple spans, but they covered the deck (including the expansion joints) with asphalt so the bridge looks continuous from the road.

The I-girders are supported by large two column bents. Note that the top of the bents have wide platforms, perhaps for jacking up the spans and replacing the bearings.

Route 54D continues another 80 miles to Guadalajara, but I turned around at this point and returned to Colima.

Mexico's Bridges: Puente Cuatro Caminos (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Puente Cuatro Caminos (1)

I've often observed that a bridge is almost unnoticeable from the roadway above. Someone driving on Route 54D towards Guadalajara might not be aware that they had driven over a canyon unless they had taken their eyes off the road.

Puente Cuatro Caminos (the Four Roads Bridge) is a tall precast girder bridge on a sharp radius horizontal curve. We'll take a closer look at this bridge tomorrow.

Mexico's Bridges: Puente Cuatro Caminos (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.

Mexico's Bridges: Puente Acatas

Another three-span precast girder bridge on two column bents and seat-type abutments. This bridge is very similar to the previously studied Puente Pialla.

Considerable effort was made to retain the slopes above the road and along the abutments. I like these handmade stone masonry retaining walls. The bridge seems more impersonal.

The deck looks like it is continuous across the three spans. The bridge crosses one of the many creeks (Acatas Creek?) running down the side of the volcanos.

Route 54D is near the base of these volcanos and runs parallel to a large river ( the previously encountered Armeria River?).

It looks like a road veers to the west away from the highway at the end of the bridge. There is a small gully a little west of the bride that drains this road into the creek.

This bridge also has asphalt spread onto the deck. This practice used to be common in California, and was sometimes done by road crews without asking the bridge engineer's opinion. It's even possible that there were expansion joints at the ends of the spans that were covered by the asphalt.

Mexico's Bridges: Puente Acatas by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Puente El Platanar

I just remembered that we had actually left the state of Colima (at the city of Tonila) and we are now in the state of Jalisco, Mexico.

The next bridge on our trip northward (on Route 54D) is Puente El Planatar. It is a three span precast I-girder bridge on two-column bents and seat-type abutments. El Planatar (translated as the banana grove) is a beautiful colonial village a few miles southeast of the bridge.

This bridge crosses over another river canyon. Note how steep the canyon wall is and the white rock layer near the top.  I wonder if that layer is from a large pyroclastic flow that occurred some time in the region's past.

It's an odd looking and not terribly attractive structure. The concrete is badly stained and the columns were built outside of the thin bent caps.  Perhaps a more monolithic structure makes for a more attractive bridge. For instance, I think the recently viewed Beltran and Pialla bridges (with their sculptural forms) are more attractive structures.

Mexico's Bridges: Puente El Platanar by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Puentes Los Lobos

Traveling north from the City of Colima on Route 54D, we enter into mountains and cross over tall bridges. A second bridge (on the left) was just beginning to be built parallel to the first bridge when I came by in 2003.

The existing bridge is a four span reinforced concrete I-girder bridge on cruciform-shaped two column bents. There are vertical stiffeners or perhaps diaphragms providing stability for the girders.

It is a four span bridge on bents at different heights with struts at different levels.

Route 54D is carried by a series of tall bridges across the many streams running down the flanks of two enormous volcanoes just west of the highway. You can see this part of the highway is in a steep cut at both ends of the bridge.

Mexico's Bridges: Puentes Los Lobos by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: PSV Ent. Jiquilpan

Eventually I arrived in the City of Colima, which is a nice region, but without many unusual bridges. However, I did see a variety of innovative interchanges in Colima as well as throughout Mexico.

I'm particularly fond of this interchange. It includes a traffic circle under a freeway undercrossing with on-ramps and off-ramps on the approach embankments.  The bridge is a six-span precast I girder superstructure on multicolumn bents and seat-type abutments.

I think this is a simple and effective means for getting people on and off expressways without traffic signals or expensive connectors.

Traffic circles are seldom used to get people on and off expressways in California. The offramp I take to get home from work (the Watt Avenue exit on US-50) is just after the expressway onramp causing everyone to stop to avoid plowing into each other as they try to get on and off the expressway.

Mexico's Bridges: PSV Ent. Jiquilpan by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Nuevo Caxitlan POC

The road from Manzanillo to Colima includes many pedestrian overcrossings (POCs) that carry people (and especially children) over the busy highway.

The Nuevo Caxitlan POC connects the town of Nuevo Caxitlan to an orchard (and farmer's markets) to the south. With its metal roof and railing, it makes a pleasant place to stand and watch the passing traffic. Apparently, it also makes a convenient place to mount advertisements and political posters.

This POC includes two spans over the highway and long zigzagging ramps along the sides of the highway. Note that the spans over the highway are made out of two precast girders laid side by side. Also note that the bent cap has big shear keys.

Mexico's Bridges: Nuevo Caxitlan POC by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Tecoman Overcrossings

Continuing northeast along the Colima - Manzanillo Highway (Route 200) is an interchange to the nearby town of Tecoman, which includes a two span and and a three span overcrossing.

These bridges are interesting because the abutments, including the stem walls, are constructed from mechanically stabilized earth (MSE) panels. I don't think we have ever used an MSE wall to support a bridge superstructure in California. It seems to be doing a good job though, especially when you consider the bridges were about 15 km from the epicenter of the 2003 M8 Colima Earthquake.

Also, I like how the area around the interchange has been landscaped with palm trees, bougainvillea, and shrubbery. The State of Colima does a nice job of maintaining their highways.

However, I wonder how effective the sign on the outside of the bridgerail 'SI TOMA NO MANEJE' (don't drink and drive) is at preventing drunk driving? It may be too late to stop someone who is already driving, but it may possibly give them pause from continuing to drink while they drive.

Mexico's Bridges: Tecoman Overcrossings by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Colima Armeria Overcrossing

The next bridge along Route 200 is a two-span overcrossing (part of a trumpet interchange) that takes eastbound drivers around a ramp and onto the northbound lanes of the Colima-Armeria Highway.

It seems to me that bridges in Mexico have a lot of character. This bridge has a precast I-girder superstructure, but it also has a beautiful hand-mortared abutment stem-wall. I like the little sidewalls (below the wingwalls) that hold back the embankment and the slope paving under the abutments. And the entire abutment structure was freshly hand painted. You can see that the highway bridges are well maintained.

Perhaps it reflects a less litigious society that there are no crash cushions or guardrails to stop an errant driver from crashing into the center pier. Instead, the pier is painted with black and white stripes to warn drivers to avoid it.

I also like the little pedestals that were poured to support each girder, the big shear keys at the ends of the bent cap, and the bright yellow barrier rails on the bridge. We'l see a lot more of these little touches on Mexican highways that make even a humble overcrossing into something special.

Mexico's Bridges: Colima Armeria Overcrossing by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Mexico's Bridges: Rio Armeria Puentes

We've travelled from the State of California in the U.S. to the State of Colima in Mexico. This is a trip I took in 2003 to look at bridge damage following a large earthquake that occurred near the coast.

The State of Colima is a pretty region. I drove north from the coastal plain up into steep mountains with quaint villages and a cloud forest with very diverse flora and fauna. The region's economy seemed healthy and the earthquake damage was quickly repaired.

I was driving on Route 200, the highway from Manzanillo on the coast to Colima in the foothills. One of the first bridges I came to was the Rio Armeria Puentes, which are two 14 span precast I-girder bridges supported on tall, thin piers with hammerhead caps and on seat-type abutments.

I like the texture of the concrete, which looks like it was formed with something other than 4' x 8' sheets of plywood. This bridge was close to the earthquake epicenter, but the only damage was to the shear keys at the abutments and to tiny keys at the tops of the pier caps.

Mexico's Bridges: Rio Armeria Puentes by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License. <