Soil based design of highway guardrail post depths using pendulum impact tests

Abstract

Guardrails are passive road restraint systems (RRS) used at roadsides and medians to improve road safety. In the case of inadequate post embedment depth of soil driven posts may not function as intended and design cannot provide adequate safety nor security for the impacting vehicles. In general, the height of the steel guardrails varies between 1600 and 2400mm. However, the characteristics of the soil where the guardrails are driven are not taken into consideration. In other words, a constant depth of guardrail is used regardless of the type of soil. Post embedment depths (PED) in steel guardrail systems are currently determined based on strong soil properties. The crash performance of these designs may not be appropriate for locations where soil conditions are weaker than tested conditions. In this study, a series of field impact tests were performed on soil embedded posts to determine optimum PED for M. Musab Erdem Iskenderun Technical University, Faculty of Engineering and Natural Sciences, Civil Engineering Department 31200, Iskenderun, Hatay, Turkey E-mail: musab.erdem@iste.edu.tr Murat Büyük Sabancı University, Integrated Manufacturing Technologies R&A Center 34956, Istanbul, Turkey E-mail: muratbuyuk@sabanciuniv.edu