Figure 1: The historic Black Canyon Arch Bridge in eastern San Diego County Hello 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 (pic […]How do you use bedrock and octagons to build a strong bridge? — Seismic Saturday
A look at how the Black Canyon Arch Bridge was built from a columnist’s perspective.