Project of the year: Special Projects

Marina del Rey Seawall Repair Project

Marina del Rey, California

Submitted by WDP & Associates, Inc.

In response to a corrosion-related collapse of a reinforced concrete panel in the Marina del Rey Seawall, an extensive multi-faceted evaluation project was launched to determine the condition of the 7.5 miles of remaining seawall defining the harbor and to develop a repair design. The $25 million project represented one of the first large-scale applications of impact-echo technology in a structural rehabilitation project.

Nondestructive testing began in February 1996, followed by two phases of repair construction, beginning in January 1997 and January 1999, respectively. Construction was completed by July 2000.

The entire length of the seawall was evaluated to determine corrosion-related strength loss. The sire-specific data were then applied to the repair concept of installing caissons to support the seawall panels via connecting tie-back rods. The in-depth structural detail discerned from the impact-echo testing results allowed a high level of refinement in the design.

The repair design was based on results from fieldwork as well as other nonlinear structural analysis and finite element modeling. Additional considerations factored into the design, beyond compensating for deteriorated reinforcement; current earthquake design loads had to be incorporated. Ultimately, by applying the data from the nondestructive testing to the results from the structural analysis, the number of required caissons was reduced from 3971 to 2473.

The success of the project is the result of many aspects of the work including incorporation of innovative evaluation techniques, use of advanced structural analysis, communication among the involved public and private agencies, and attentive project management. These elements not only fulfilled the project goals, but also extended the benefit of the work to the greater Marina del Rey community via the budgetary surplus funds of $500,000, subsequently applied to street repairs. Finally, though, the success of the project is measured by the continued integrity of the seawall.

Owners
County of Los Angeles Department of Beaches and Harbors
Marina del Rey, California

Los Angeles County Department of Public Works
Alhambra, California

Project Engineer/
Designer
WDP & Associates
Austin, Texas

Project Engineer/
Designer
(Corrosion System)
Corrpro Companies Incorporated
Santa Fe Springs, California

Construction Manager
CMA
El Segundo, California

Repair Contractors
Clarke Contracting Corporation
Lawndale, California

Southwest Engineering, Inc.
Santa Monica, California

Amelco Electric
Gardena, California