Seismic Vulnerability of the Highway System

Task G4-1: HITEC Response Modification Bearing and Dissipater Evaluation - Follow-on Study

Subject Area: Technology Exchange and Transfer 
Research Year 2

Principal Investigator(s) and Institution(s)

Ian M. Friedland, Applied Technology Council


In the mid-1990's, the Civil Engineering Research Foundation's (CERF) Highway Innovative Technology Evaluation Center (HITEC) initiated a program to evaluate seismic response modification devices (SRMDs) (at that time known as seismic isolation and energy dissipation devices), which were being marketed by various product vendors to the bridge engineering community. The program was co-sponsored by the Federal Highway Administration (FHWA) and the California Department of Transportation (Caltrans), and was conducted by HITEC and Caltrans following the typical HITEC product evaluation approach. The deliverables resulting from this evaluation program included a guidelines report, which documented the testing protocol (CERF Report No. 40612); a series of technology evaluation reports, one for each device tested under the program (CERF Report Nos. 40365 - 40370, 40373, 40376, 40401 - 40403); and a summary/synthesis report (CERF Report No. 40404), discussing the overall evaluation program and testing results.

These reports document the test procedures and individual product test results. In their current form, they provide little information to structural designers regarding the applicability of a given technology for specific applications under the range of actual conditions that may be found in various environments (relating to both seismic hazard demands and environmental conditions; e.g., temperature or humidity ranges), and no guidance on how to incorporate such technologies into the bridge design process. The HITEC reports are also, by their nature, "static" and do not accommodate updating when improvements are made to a specific device, nor for incorporation of information as new devices and technologies become available and are similarly evaluated. Furthermore, there is a wealth of useful data that was generated during the HITEC evaluation that is not readily available to the general bridge engineering or bridge research communities.

The HITEC evaluation was conducted under the direction of a panel comprised primarily of bridge engineering practitioners (state DOTs and consultants); the panel also included one university researcher and several FHWA staff.

Following publication of the HITEC reports, a few questions were raised by members of the bridge engineering community regarding issues concerning the test protocols used in the program, and the integrity of the data used during the preparation of the reports. Some of these concerns addressed the issues of data averaging and possible filtering, and how certain performance characteristics were calculated. The vast majority of these concerns have been put to rest, but in order to ensure acceptance of the final products of this study, it is important to independently re-assess the test protocols and data obtained during the HITEC testing program during the initial stages of the project.


The objectives of this project are to independently re-assess the test protocols and test data collected and reported during the HITEC program, and to develop tools and procedures that can assist design engineers in determining whether and how SRMD technologies can be incorporated into bridge the design and retrofitting process. The specific objectives of this project include:
  1. Conduct of an independent technical review and assessment of the test protocols, and "raw" and reported data resulting from the HITEC product evaluations;
  2. Development of tools and guidelines that can assist bridge designers in the evaluation and selection of appropriate SRMD technologies during the bridge design and retrofitting process. This will entail a synthesis of test result data, current literature and research on SRMD technologies, and a review of recent designs that have incorporated such technologies; and
  3. Development of a mechanism to make all HITEC data available to the bridge engineering and research communities, and to provide a mechanism for keeping SRMD evaluation and performance data current as new technologies come to market and as existing devices are improved or modified.

For Objective 2, one possibility would be to provide a series of tables or curves into which desired bridge performance parameters can be entered, and from which specific recommendations can be obtained regarding SRMD technologies appropriate for that bridge application. This report could be supplemented by examples demonstrating the interpretation of the HITEC data, design procedures, and case application histories.

Objective 3 can be accomplished via a number of ways; however, with the emergence and power of Internet-based applications and the relative low cost of CD-ROM based products, it is anticipated that a combination of these approaches may be appropriate.


A consultant will be employed to conduct the actual work on Objectives 1 and 2; the consultant will be selected based on his/her knowledge and expertise in the testing, design, and application of SRMDs. ATC will empanel a Project Engineering Panel (PEP) comprised of appropriate practitioners and researchers, who will provide oversight to the work being conducted by the consultant. Work on Objectives 1 and 2 will be conducted in cooperation with CERF. It is anticipated that CERF will take the lead in conducting Objective 3, in cooperation with ATC. 

Objective 1 will be initiated after a meeting of the PEP. The project consultant will be charged with reviewing the HITEC test protocols, and assessing the "raw" SRMD data. The consultant will also review the results presented in the various HITEC reports, in order to determine if they are adequately and fairly represented. If the data is deemed viable, a detailed work plan for Objectives 2 and 3 will be developed and, if funding is available, these phases of work will be initiated.

Careful consideration must be given to membership on the PEP; it will therefore be determined following discussions between ATC, MCEER, CERF, Caltrans and the FHWA. It is anticipated that both ATC and CERF will appoint liaison members to the PEP.


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