The historic La Loma Bridge across the Arroyo Seco, originally constructed in 1914, underwent a seismic retrofit and rehabilitation and was renamed The John K. Van De Kamp Bridge in the re-opening ceremony in June, 2017. The bridge has been selected as a Best of 2017 project by the APWA (American Public Works Association).
The need to improve the bridge structurally had been identified several years ago, prompting a study of alternatives to address the strengthening or replacement of the bridge. Pasadena Heritage is constantly monitoring projects in the City for issues of relevance to historic preservation, and raised the alarm when the City proposed to demolish and replace the bridge. At the time, PECK Principal Chris Peck wrote an article for The West Pasadena Residents' Association Newsletter making the case to keep and restore the bridge based on its historic, artistic and cultural value.
After the decision had been made to pursue this approach and funding had been identified under the leadership of City Council Member Madison, a citizen’s Design Advisory Group was established to help guide the process. The design of the bridge was complicated by the discovery that the Raymond Fault runs directly beneath the East Pier, and could experience a lateral displacement of up to 3 feet. The City hired Dokken Engineering to be the bridge design consultant and through several working sessions with the Citizen’s committee, the City Engineering staff, and Dokken discussing strategy and possibilities, a reconstruction strategy was adopted. Base isolation strategies were discussed, but ultimately a strategy involving the replacement of the upper level minor arches, the bridge deck, as well as the abutment structures was adopted. Thankfully, the original design drawings for the bridge were available for review and the opportunity to reconstruct elements of the bridge that had previously been demolished, such as the balustrades and light standards could be realized.
Dokken proposed using a box girder design that would allow the bridge to remain standing after the collapse of the east pier. The bridge deck would also have to be widened by 2 feet on each side to meet minimum standards in terms of roadway geometry. The Design Advisory Group agreed to implement Chris' design suggestion to retrofit the supporting piers utilizing twin columns that hug the interior of the historic piers. The pier that was going to hold up the box girder went from being a single central pier, which would have been an obvious deviation from the original design geometry, to a split pier which is less intrusive yet conveys a sense of what's original and what's not.
La Loma Bridge Tower Retrofit Option
WITH HISTORIC PRESERVATION PROJECTS THERE IS OFTEN TENSION BETWEEN THE DESIRE TO CREATE EXACT REPRODUCTIONS - EXTENSIONS OF THE ORIGINAL DESIGN LANGUAGE VS. MAKING WHATEVER IS NEW, DIFFERENTIATED, SO THAT YOU CAN RECOGNIZE WHAT'S ORIGINAL AND WHAT IS NOT.
The upper deck, balustrades, light standards, brackets, and spandrel arches bridge are being faithfully reconstructed to restore the original historical elegance of the bridge using the details of the original design drawings from 1914, but structurally, the bridge is different. No longer an arch bridge, La Loma is now a box girder bridge.
The Design Advisory Group has been tasked with reconciling the finishes of the fixtures and the textures and colors of three different types of concrete: original with bonded grout; precast; and cast-in-place, all of which will exist side by side on various elements of the structure.
What began as a replacement project evolved into a restoration project. The bridge has been through an interesting design process and it's great to show people how it all worked now that it's in its final phases. The project is coming to fruition and will be re-opening soon!
Photo credit: GPA Consulting
April 28: nearing completion!
City and Consultants:
Dokken Engineering - Bridge Design Consultant to the City of Pasadena. They did a great job taking into consideration the historic elements of the project.
Cal Zachman of Vali Cooper Construction Management – consultant to the City of Pasadena is doing a great job pulling together all the players and bringing issues up in a timely manner.
Brent Maue – City Public Works employee assigned to the project is responsible for administering the contract for construction. Steve Wright and Dan Rix before him were leading the project for the City of Pasadena as City Engineer.
Steve Madison – District 6 council member was effective in pursuing the funding.
Roubik Mardirosian – City of Pasadena Project Manager
Citizen Design Advisory Group:
Sue Mossman, Executive Director and Jesse Lattig, Preservation Director of Pasadena Heritage.
Ann Scheid, local historian, was a part of the DAG to comment on matters of historical importance.
Michael Krakower, structural engineer, expert in Structural Rehabilitation of historic structures and Pasadena Heritage Board Member provided review and guidance to Dokken and the team.
Robert Carpenter and Andrea Rawlings, both architects, are also part of the DAG.
Members of DAG and the Pasadena Construction management team