EVALUATION OF AN EXISTING STEEL POST ALTERNATIVE FOR THE THRIE BEAM BULLNOSE GUARDRAIL SYSTEM

Authors

Robert W. Bielenberg, University of Nebraska - LincolnFollow
Ronald K. Faller, University of Nebraska - LincolnFollow
John R. Rohde, University of Nebraska - LincolnFollow
John D. Reid, University of Nebraska - LincolnFollow

Date of this Version

2007

Document Type

Article

Citation

MwRSF Research Report No. TRP-03-193-07

Abstract

Recently, the Minnesota Department of Transportation (MnDOT) funded a research project through the Midwest States Regional Pooled Fund to evaluate an existing steel post alternative for the thrie beam bullnose barrier system previously developed at the Midwest Roadside Safety Facility (MwRSF). MnDOT had an interest in the replacement of the wooden breakaway posts used in the current bullnose system with proprietary breakaway steel posts. The research project consisted of evaluation of current breakaway steel post designs, investigation and selection of a candidate post design, and full-scale testing of the bullnose system with a steel post alternative. The full-scale testing was to consist of two tests conducted according to the evaluation criteria of NCHRP Report 350:

1. 1) Test 3-38, an impact of a 2000P vehicle on the Critical Impact Point (CIP) of the system at a speed of 100 km/h and an angle of 20 degrees, and

2. 2) Test 3-31, an impact of a 2000P vehicle with the center of the vehicle aligned with the center of the nose of the system at a speed of 100 km/h and an angle of 0 degrees.

The evaluation of the steel post alternative for the bullnose system project has been completed. A steel post alternative was selected followed by two full-scale crash tests. Unfortunately, both crash tests failed as the vehicle in each test ramped up the guardrail and vaulted the system. This letter summarizes the work completed.