Bridges and Other Structures to Excite your Curiosity
About the Blog
Saul Chaplin started #SeismicSaturday in 2020 as a blog on innovative, historic, or just downright cool structures. He learned, while writing, that bridges are super interesting. They arise out a simple need: to get from point A to point B without getting wet. From that simple problem statement sprouts infinite challenges, technicalities, and opportunities for creativity. What if the river valley is 1200 ft deep, in a seismically active area, subjected to high temperature extremes which cause problematic expansion and contraction of members, exposed to highly corrosive marine air? What if the ground is a swamp, or alternately, the “valley” is two shear cliff edges? What if the client desires an interesting cable-stayed bridge with a curved deck, or a smooth and aesthetic arched bridge, or a rustic wooden truss, or an octagonal girder bridge? The challenges – and thus the possibilities – are endless.
You are invited to explore the bridges and other structures on the blog. Scroll down to see featured posts, or select Bridges or Other Structures. Search structures by location on the map. Please leave a comment with a question, comment, or link to another cool structure!
Featured Posts
Cruz del Sur: a Seismically-Resistant Coral-esque Structure
How do you build an earthquake-resistant structure that looks like coral? This Seismic Saturday, we travel to Santiago, Chile, to feature the Cruz del Sur Building. The first thing that the eye catches is the structure’s surprising form, starting thin and expanding outward up the building (figure 2). A thick central shaft, which takes both…
The Carbon Fiber Cable-Stayed Bridge that Could Have Been…
The bridge that could have been… For #seisimicsaturday we feature the proposed (but never built) carbon fiber/fiberglass Gilman Street Bridge. With UC San Diego expanding east in the 90s, there was need for a bridge across highway 5 at Gilman Drive. Several UCSD professors, among them prof. Van Den Einde and Frieder Seible, designed an innovative cable-stayed…
Richmond San-Rafael Retrofit: “The most complex single retrofit program ever attempted by Caltrans”
“Mr./Ms. Engineer, your mission, should you choose to accept it, is to retrofit the Richmond-San Rafael ‘roller coaster’ Bridge. The bridge, measuring 22,000 ft, has 4 different steel structural systems along its length. Most spectacular are the two 1070 ft spans over active shipping channels – each made by two 535 ft-long cantilever arms that…
How do you use bedrock and octagons to build a strong bridge?
This #seismicsaturday, we feature the Black Canyon Arch Bridge, built in 1913 Northeast of Ramona in Eastern SD County. An arch relies on its foundations to push both upward and inward. The shallower the arch, the more sideways force is needed (fig. 2). For the Black Canyon Bridge, the arch is built directly into the bedrock…
Retrofitting San Diego’s “People’s Bridge” to be Seismically Safe
Shrouded by eucalyptus in Maple Canyon is one of San Diego’s most impressive bridges. This #seismicsaturday we feature the 1st Avenue Bridge. The 463-foot bridge was built in 1931, and is nicknamed “The People’s Bridge” as it was funded by San Diego’s first public infrastructure tax. The bridge was actually assembled first in Ohio, before…
Can You Make a Bridge Out of Telephone Poles?
This #seismicsaturday we feature a 150ft long bridge over the Ausable River in the Adirondacks Mountains of New York. The bridge foundation is built from stones piled on top of one another, with cement in between (pic 2). The foundation is built in a hydrodynamic shape with a pointed front, making it look similar to a boat…
Quince Street Bridge: The Oldest Functioning Bridge in San Diego
What is the oldest functioning bridge in San Diego? This #seismicsaturday we feature the Quince Street Bridge. The Quince St. Bridge was built in 1905 to connect residents of the then fast-growing Bankers Hill neighborhood to the trolley line in 4th avenue. The bridge is 263 ft long and 60 ft tall. It cost just…
“El Mirador” Observation Platform in Baja California, Mexico
We travel south of the border this #seismicsaturday to Baja California, Mexico. Featured is an observation platform at “El Mirador” (The Lookout) in San Pedro Mártir Nacional Park, at 9100 ft. ⛰️The platform is made with a cantilever steel truss structure. The main truss extends outward, reducing its depth as it goes (Fig. 2). Secondary truss structures…
Saul Chaplin 