A Study of the Deflections of Metal Road Guardrail Elements

Abstract

Abstract. Statistical data on traffi c accidents in 2008 inLithuania is presented. Referring to statistical data, 'grounding on an obstacle' makes one-tenth of all registered traffi c accidents -9.4% (an obstacle may be a road guardrail, a lamp post, a tree, a bar, a gate, etc.). Road guardrails of various types are installed on the shoulders and dividing strips of urban and suburban roads. Th ey are as follows: reinforced concrete guardrails, cable guardrails and metal guardrails. Metal guardrails, consisting of Σ-shape metal posts and a protective W-shape horizontal beam, are most popular. Th e authors of the present paper examine the deformation processes of the elements of the above mentioned guardrail. A mathematical model of metal road guardrail was developed. Metal road guardrail was modelled using onedimensional fi rst-order fi nite elements, taking into account only elastic deformations, as well as the eff ect of soil on the buried post section of the guardrail. Based on the developed mathematical model of metal road guardrail, the defl ections of its elements caused by the impact of a vehicle moving at varying speed were determined. Th e obtained values of defl ections of guardrail elements (a protective W-shape horizontal beam and a Σ-shape post) presented in paper do not exceed the admissible values (of beam defl ections).

The Improvement Conception of Drivers Training and Examination System in Lithuania / Vairuotojų Rengimo Ir Egzaminavimo Sistemos Lietuvoje Tobulinimo Koncepcija / Концепция Совершенствования Системы Подготовки И Аттестации Водителей В Литве

“…A considerable harm is caused by traffic accidents when humans perish and are injured, vehicles and road constructions are damaged, the environment is polluted by spilled fuels, oils and transported materials (Baltrenas, Kazlauskiené 2009;Baltrenas et al 2008;Baltrenas, Puzinas 2009;Peceliünas, Prentkovskis 2006;Vaisis, Januáevicius 2009;Prentkovskis et al 2009aPrentkovskis et al , 2010aPrentkovskis et al , 2010bSapragonas, Darguzis 2011;Rukuiza, Eidukynas 2009;Cygas et al 2009;Leipus et al 2010;Pellegrino 2009;Antov et al 2009;Cerniauskas et al 2010;Vitkùnas, Meidute 2011;Jagniatinskis et al 2011).…”

The Analysis of the Deformation State of the Double-Wave Guardrail Mounted on Bridges and Viaducts of the Motor Roads in Lithuania and Ukraine

“…In particular, some of them (Mučinis et al 2009;Ambrozi-ak, Korzeniowski 2010;Hassan, Al-Jabri 2011;Hartleb, Ketting 2011;Wang et al 2011a;Sivilevičius 2011a;Sivilevičius et al 2011;Krayushkina et al 2012;Li et al 2012, etc. ) focus on the study of pavement quality, while others (Beljatynskij et al 2009;Prentkovskis et al 2009Prentkovskis et al , 2010aČerniauskas et al 2010;Žiliūtė et Stanić et al 2011, etc. ) and interaction between various elements of transport systems (Beljatynskij et al 2009;Prentkovskis et al 2009 Road traffic infrastructure plays an important part in ensuring traffic safety on urban roads and highways.…”

“…) focus on the study of pavement quality, while others (Beljatynskij et al 2009;Prentkovskis et al 2009Prentkovskis et al , 2010aČerniauskas et al 2010;Žiliūtė et Stanić et al 2011, etc. ) and interaction between various elements of transport systems (Beljatynskij et al 2009;Prentkovskis et al 2009 Road traffic infrastructure plays an important part in ensuring traffic safety on urban roads and highways. It includes guardrails, speed bumps, pedestrian safety islands, traffic regulation systems, road information infrastructure, etc.…”

“…Theoretical aspects of guardrail analysis A guardrail is a mechanical system. To derive an equation of motion of the finite element, the Lagrange equation of the second kind is used (Zienkiewicz et al 2005;Prentkovskis et al 2009Prentkovskis et al , 2010a.…”

“…Then, the expressions of the kinetic and potential energy, as well as dissipative finite element function and the vector of the external forces, acting on the finite element, are written (Prentkovskis et al 2009(Prentkovskis et al , 2010a, taking into account that the displacements in the finite element are approximated as follows: Substituting the expressions of the kinetic and potential energy, the dissipative function of the finite element and the vector of the external forces, acting on it, into the Lagrange equation of the second kind, a system of motion equations for the finite element is obtained in the matrix form:…”