California Department of Transportation

About: California Department of Transportation is a government organization based out in Sacramento, California, United States. It is known for research contribution in the topics: Poison control & Seismic analysis. The organization has 308 authors who have published 389 publications receiving 12623 citations. The organization is also known as: Caltrans & Bureau of Highways.

Bridge Engineering : Seismic Design

Abstract: Mitigating the effects of earthquakes is crucial to bridge design. With chapters culled from the best-selling Bridge Engineering Handbook, this volume sets forth the principles and applications of seismic design, from the necessary geotechnical and dynamic analysis background to seismic isolation and energy dissipation, active control, and retrofit

Quality of service for interrupted-flow pedestrian facilities in "highway capacity manual" 2000

Abstract: The objective of the research described in this paper was to develop the basis for revised operational analysis procedures for transportation facilities with pedestrian users where flow is interrupted by traffic control devices. The paper commences with some background information on pedestrian walking speeds at signalized crossings and on pedestrian noncompliance at these locations. Then both new and revised level-of-service (LOS) tables are provided for analyzing various types of interrupted-flow pedestrian facilities. Results are detailed of a review and synthesis of American and international literature as part of a Federal Highway Administration study of pedestrian and bicycle facilities conducted by North Carolina State University between 1995 and 1998. The year 2000 edition of the U.S. Highway Capacity Manual (HCM) will incorporate, either directly or indirectly, most of the revised and synthesized information described in this paper. The research team recommends that the HCM include some backgroun...

Bridge management for the 21st century

Abstract: Bridge management has been a subject of intense interest and development for the past 10 years. In support of improved bridge management, FHWA funded the development of the Pontis bridge computer program, which is now in use by approximately 40 of the 50 states. In addition, many new guide specifications have been produced to assist bridge managers in their efforts to better manage the nation's aging bridge inventory. The AASHTO Subcommittee on Bridges and Structures has taken the lead along with FHWA in implementing the improved bridge management systems. California and a few other states have been critical of the current ranking system for bridge maintenance and have been working to develop an improved performance measure. The bridge health index (HI), an improved and more comprehensive numerical rating system that uses the element inspection data to determine the remaining asset value of a bridge or network of bridges, is discussed. The HI is more consistent with the element-level evaluation data colle...

Rapid Repair of Earthquake-Damaged RC Columns with Prestressed Steel Jackets

Abstract: In this study, a lightweight prestressed steel jacket (PSJ) was proposed and developed for rapid and cost-effective repair of a severely damaged circular reinforced concrete column. The PSJ is composed of several prestressed strands, and a thin steel sheet is restrained by these strands, which can be manually wrapped around and jointed to form a jacket on the column as part of a 12-h repair job by two workers. The prestressed strands restrain the thin sheet from buckling, while the steel sheet in turn prevents the strands from cutting into cracked concrete and thus preserves the prestressing forces. The PSJ was validated with cyclic (reversed) testing of two large-scale columns with lap-splice deficiency under incrementally increased displacements every three cycles. The ultimate strength and displacement ductility of the damaged column were restored to 115% and 140%, respectively, of those of the as-built column. The initial stiffness of the damaged column, however, was restored to only 84% of th...