Condition Assessment & Nondestructive Testing: Projects

Marina del Rey Seawall Rehabilitation

Los Angeles, California

The 7.5 mile long Marina del Rey Seawall was constructed during the late 1950’s and early 1960’s as a means of reclaiming a low lying swamp area for dry land uses and to provide a harbor for recreational boats. The original construction was high quality for the time, as evidenced by its 40 plus years of service life to date. Today, approximately $5 billion of infrastructure and commercial construction surrounds Marina del Rey.

In 1986, a 60 foot wall panel collapsed due to severe corrosion of the vertical reinforcement at a construction joint located near the base of the wall. The long-term exposure to tidal fluctuations led to chloride-induced corrosion of the reinforcing steel crossing the construction joint and attendant concrete deterioration on the hidden (land) side of the wall. Given the era of the original design and construction, an evaluation also revealed that the seawall was not designed for earthquake loading. Moreover, site-specific geologic and geotechnical considerations place Marina del Rey in a known risk area for soil liquefaction.

WDP was retained as the Engineer-of-Record for the Marina del Rey Seawall Rehabilitation Project. Nondestructive testing was conducted on each of the 728 wall panels to define where corrosion damage in the form of concrete delamination had occurred on the tension (land) side of the wall. Damage was found to vary greatly between panels – from virtually no corrosion damage to extensive damage along the entire length of the construction joint. Thus, individual wall panel repairs were categorized based on known extent of corrosion damage and life-safety concerns along wall areas with high public exposure.

WDP designed a cost-effective tie-back system to strengthen the wall based on the extent of corrosion damage and code-required seismic resistance. By conducting the nondestructive testing and tailoring the repairs based on damage detected, Los Angeles County Beaches & Harbors saved more than $6 million in construction costs. The project was awarded the International Concrete Repair Institute (ICRI) Project of the Year in 2002. WDP has monitored the wall for development of additional corrosion damage every three to five years.

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The Solomon R. Guggenheim Museum

New York, New York

The Solomon R. Guggenheim Museum was designed by the renowned architect Frank Lloyd Wright and is a designated architectural landmark structure. Construction began in 1956 and was completed circa 1959. WDP was retained to assist a team of restoration professionals in the evaluation of corrosion damage at the building, principally of the iconic shotcrete Rotunda wall construction. The investigation was conducted through a program of nondestructive testing that assessed the corrosion activity of embedded reinforcement, quantified the ability of the shotcrete and concrete to resist current flow, and quantified the presence of chloride ion, which is a known promoter of corrosion. The field testing revealed that, for the vast majority of the areas examined, there is no significant corrosion activity occurring. The corrosion and corrosion damage that has occurred has been limited primarily to crack locations at the intersection of the shotcrete façade and web walls, and at embedded steel T’s and posts that were apparently utilized in the original wall construction. These cracks likely formed due to long-term effects from restrained shrinkage. The evaluation indicated that widespread corrosion of the facade and other selected components is not occurring at this time. In the vast majority of areas, the various layers of coating applied over the past five decades have afforded good protection to the steel. Based upon these results, the implementation of a repair and maintenance program will significantly extend the service life of the exposed exterior components. The report by WDP included specific recommendations which addressed the observed damage as well as recommendations for long-term preservation of the iconic façade.

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Field House Corrosion and Structural Evaluation

Washington, DC

WDP was retained to evaluate the effects of long-term water penetration through the roof of a 30 year-old field house comprised of a series of thin concrete shells.  The upper surface of the structure serves as an exterior playing field, with the interior space used as a multi-purpose field house.  The long-term water penetration through the roof led to concerns about the condition of both the mild reinforcing steel and post-tensioning tendons in the concrete shells.  WDP utilized a combination of electro-chemical corrosion tests, material tests and physical probes to evaluate the condition of the reinforcement.  These results were used in analysis models to evaluate the in-place strength of the concrete shells.

The results of the testing indicated that damage due to corrosion was possible within a 2 to 5 year time frame in isolated, continually wet locations.  Physical probes also indicated water had penetrated the sheathing of the post-tensioning tendons. Based upon the results of the testing and structural analyses, recommendations for repairs were developed.

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Holmdel Towne Center

Holmdel, New Jersey

WDP was hired to perform structural evaluation and repair of the exterior masonry and roofing for a 300,000 square foot retail shopping center. Infrared Thermography (IR) and a pachometer survey were conducted to nondestructively identify inadequately grouted cells and incorrectly installed reinforcement, respectively. Surface Penetrating Radar (SPR) was also used in some locations to identify and determine the length of reinforcing bar splice lengths. Based on the nondestructive testing, WDP provided as-built drawings depicting locations of grouted and reinforced masonry cells. Additionally, structural analyses of the masonry walls and structural steel framing were performed to determine if the as-built conditions were sufficient to resist the applicable design loads.

Because of deficiencies in the design and construction of the facility, repairs were warranted. WDP developed repair documents based on the as-built conditions and corresponding analyses. Full time inspection and on-site engineering were provided during the repair phase along with litigation support to owner’s counsel. During this full time engineering, some of the same nondestructive tools used to identify the problems throughout the development were used as a QA/QC measure to ensure proper repairs were administered.

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