Las Encinas Creek Bridge had been deteriorating for decades due to the harsh marine environment in which it is located. NV5 performed a structural assessment analysis of the old T-beam structure and recommended that the bridge should be replaced as soon as possible. The City of Carlsbad retained NV5 to provide design services for the replacement of Las Encinas Creek Bridge along southbound Carlsbad Boulevard.
NV5 examined many alternatives for the bridge opening, specifically pre-cast box culverts, cast-in-place box culverts, and ConSpan Arch Systems. NV5 performed hydraulic and scour calculations for the bridge crossing along Encinas Creek. The hydraulic calculations were used to size the opening needed to convey the 100-year storm event.
Because the bridge is located along the coast and near a state park, the construction duration was heavily weighed when the alternatives analysis was performed to determine the best solution. With a maximum window of five months for construction, the City and NV5 agreed that the Accelerated Bridge Construction methodology (ABC) using a pre-fabricated arch system was the best choice.