CASE STUDIES PROJECT

The case studies project is an extension of the multiyear project leading to publication of the NEHRP Guidelines for the Seismic Rehabilitation of Buildings and its Commentary in late 1997. The project is expected to contribute to the credibility of the Guidelines by providing potential users with representative real-world application data and to provide FEMA with the information needed to determine whether and when to update the Guidelines.

Although the Guidelines documents reflect expert experience, current research, and innovative theories, the case studies project is expected to answer a number of critical questions: Can the Guidelines and its Commentary be understood and applied by practicing design professionals of varying levels of experience?

Do the Guidelines result in rational designs generated in a reasonable and logical way? What are the costs involved in seismically rehabilitating various types of buildings to the optional levels of performance both above and below the Guidelines' "basic safety objective"? Are the requirements to achieve the "basic safety objective" equivalent to, less stringent than, or more stringent than current practice for new construction?

Under the case studies project, seismic rehabilitation designs are being developed for about 50 buildings or building equivalents selected insofar as practicable from an inventory of buildings already determined to be seismically deficient under the implementation program of Executive Order 12941 and considered "typical of existing structures located throughout the nation." Where federal buildings from this inventory did not represent the full spectrum of buildings which need to be studied, case study candidates were sought from among privately owned buildings or those owned by other levels of government. Qualified structural engineering or architectural/engineering (A/E) firms have been engaged to produce detailed designs for seismic rehabilitation of the lateral-load-resisting systems, foundations, and critical nonstructural elements of the selected buildings, and to make specified comparisons with current practices and costs.

Each design contractor's products and experiences using the Guidelines will be assessed in order to generate credible data that will establish the technical validity of the Guidelines, define their economic impact, and identify any needed changes in the Guidelines or highlight areas in need of research and investigation before a Guidelines update is planned.

The case studies will include consideration of numerous design approaches, options, and determinations to give a balanced representation, within the resources available, of the following factors: different performance levels and ranges, both systematic (linear/nonlinear, static/dynamic) and simplified analysis methods as presented in the Guidelines, alternate designs and cost comparisons for the same building provided by more than one design firm, different structural systems, varying seismicity (high, medium, and low), short and stiff versus tall and flexible building types, rehabilitation Guidelines compared to current new construction practices, geographic dispersion of cases among seismic risk areas, presence of auxiliary energy dispersion systems or base isolation, and historical preservation status of building.

The project is being guided by the Case Studies Project Committee (CSPC) chaired by Daniel Shapiro, Principal Engineer, SOHA Engineers, San Francisco, California.

At its organization meeting in May 1997, the CSPC reviewed the background and structure of the project; developed an initial work plan/project schedule, and defined the roles of the various participants. The CSPC also established three subcommittees to address the development of criteria for building selection, design professional selection, and contractor requests for proposals. In addition to the architects/engineers who have been engaged to perform the case studies designs, the BSSC has engaged Andrew Merovich as a paid Project Technical Advisor and a Design Assessment Panel of professionals knowledgeable about the content and use of the Guidelines.

In early 1998, FEMA asked that the case studies be coordinated with its Project Impact effort; this has been accomplished by incorporating the historic Arctic Building in Seattle, Washington (a Project Impact city). FEMA also requested that the case studies project include an example from the University of California's Berkeley campus, and Tolman Hall has been included. The historic Weatherford Hall on the Oregon State University Campus also is being incorporated at FEMA's request.

An extensive selection process was employed to identify and select qualified firms to perform the case studies. Of 149 firms that responded to an initial call for expressions of interest, 133 were screened and invited to submit statements of qualification. From the 120 responses received, and ad hoc CSPC task group matched the candidate firms with the available buildings based on the experience and interest of the firms and the level of complexity expected to be involved in the design for each building. This objective selection process was documented by the BSSC staff and approved by the FEMA contracting officer.

Contracts subsequently were negotiated and awarded to 35 firms in the first phase of the project. These firms have begun their work and are scheduled to submit their reports by September 30, 1998.

The BSSC staff also has completed professional services agreements with the 12 engineers serving as the Design Assessment Panel. The panel members are providing continuing liaison with the design contractors and will serve as expert reviewers of preliminary and final designs.

A planned second phase of the project recently was authorized by FEMA. This phase provides funding to conduct five unique case studies where newly design buildings will be tested under the Guidelines to assess the differences between the Guidelines and the current building codes for new construction. In addition, three case studies from geographic locations not covered in the first phase are being added.

Incorporation of the second phase has resulted in the target date for completion of the entire project to be extended to September 1999.

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