01781395

Component

https://doi.org/10.1177/03611981211031222

The traditional, triangular yield-line method used by most departments of transportation for analyzing concrete traffic barriers and bridge rails has been largely unchanged since 1978. Testing of concrete barriers since this time has indicated that the triangular yield-line method is not qualitatively representative of observed damage patterns and is overconservative. Further, the conversion from NCHRP Report 350 to the crash test criteria from the Manual for Assessing Safety Hardware (MASH) will result in increases to lateral impact loads; therefore, overconservative analysis practices may result in many concrete barriers being unnecessarily deemed inadequate. In this research, alternative analysis methods for concrete barriers were extracted from an extensive literature review of concrete barrier investigations. These methods were applied to a sample of eight concrete barriers to demonstrate and compare their effects on capacity estimates. Alternative methods included trapezoidal yield-line mechanisms, effects of impact heights lower than the top of the barrier, punching shear evaluation, and consideration of expected material strengths. Capacity estimates of the selected barriers were increased by an average of 47?percent when alternative methods were cumulatively applied. Although the traditional method does not consider punching shear, the capacity of one of the eight barriers was controlled by punching shear rather than by yield-line flexure. With the alternative methods applied, seven of the eight barriers were deemed adequate relative to the increased lateral loads corresponding to MASH criteria for Test Levels 2 through 5. By contrast, if analyzed according to the traditional method, three of the eight barriers would have been deemed insufficient considering MASH loads.

The opinions and conclusions expressed or implied in this paper are solely those of the authors. They are not necessarily those of the TRB, the National Research Council, AASHTO, or the U.S. government. © National Academy of Sciences: Transportation Research Board 2021.

English

0000-0002-8664-7520

0000-0002-0659-1249

0000-0001-7660-1572

pp 689-701

2021-12

Transportation Research Record: Journal of the Transportation Research Board

Web

References (29)

Barriers (Roads); Bridge railings; Crash tests; Test procedures; Yield line method

AASHTO Manual for Assessing Safety Hardware; NCHRP Report 350

Bridges and other structures; Design; Highways; Safety and Human Factors

TRIS, TRB, ATRI

Sep 6 2021 3:12PM