Gazing out over Devil’s Canyon Creek, did you know that the Poema Place Bridge stands as a testament to modern steel bridge design? It serves as the gateway to Deerlake Ranch, a master-planned community northwest of Los Angeles.
This bridge isn’t just a pretty face. It overcame unique design and construction challenges. Its high visibility and location across an environmentally sensitive canyon made things tricky. The area is in a high-seismic zone too.
Protecting the creek was paramount. Devil’s Canyon Creek is a protected wildlife corridor. It’s important for community members connecting with nature. Cyclists, hikers, and equestrians use the trail system here. It connects to the Santa Susana Mountains.
Construction access was excluded from the riparian zone. The bridge had to stretch across the canyon. Consor, the engineers, developed a steel girder configuration for this long span. The pier location was carefully chosen for accessibility and geologic stability. The bridge is founded on spread footings and cast-in-drilled-hole piles. These are outside the protected zone.
Steel’s flexibility allowed for longer spans. This eliminated the need for temporary supports. The Poema Place Bridge is 49 feet wide. It consists of spans of 163 feet, 194 feet, and 116 feet. That’s a total length of 473 feet. The steel I-girders vary in depth. They go from 6 feet at midspan to 9.5 feet at each pier. In total, the structural steel weighs 496 tons.
Installing the spans required massive cranes. These were supplied by Bragg Crane and Rigging Co. The cranes erected the girder elements above the environmentally sensitive areas.
The bridge also provides seismic resilience and utility connections. The Deerlake Ranch developer was responsible for connecting the community. The open structure carries all utilities across the canyon. These include gas, water, cable, electric, and fiber optics. Ownership will transfer to Los Angeles County. Therefore, it conforms to Caltrans guidelines.
Opting for steel girders reduced the weight. This improves performance during earthquakes. Concrete piles were socketed into the sandstone for support. Two concrete columns connect to the pier cap with a pin connection. This improves flexibility.
The bridge uses low-maintenance bearings. These allow movement for temperature changes. A unique seismic restraint system engages the abutments during earthquakes. Steel tubes yield and crush, dissipating seismic energy. Post-earthquake, the tubes can be replaced. This makes the bridge ready for another event.
Aesthetics were a high priority. The bridge is the gateway to a premier development. It’s a landmark for those enjoying the Santa Susana Mountain trails. Weathering steel gives the bridge a rugged look. This blends into the natural context. The increased girder depth at the piers provides an elegant arch.
The Poema Place Bridge carries two lanes of traffic, pedestrian sidewalks, and utilities. It stands 100 feet above the canyon floor. It’s a focal point in this scenic location. It shows how material selection and seismic features can create a functional structure. It is also aesthetically pleasing. The Poema Place Bridge truly embodies sustainable steel bridge design.