Pavement roads and transportation systems are crucial assets for promoting political stability, as well as economic and sustainable growth in developing countries. However, pavement maintenance backlogs and the high capital costs of road rehabilitation require the use of pavement evaluation tools to assure the best value of the investment. This research presents a methodology for analyzing the collected pavement data for the implementation of a network level pavement management program in Kazakhstan. This methodology, which could also be suitable in other developing countries' road networks, focuses on the survey data processing to determine cost-effective maintenance treatments for each road section. The proposed methodology aims to support a decision-making process for the application of a strategic level business planning analysis, by extracting information from the survey data.
In this study, a simple guardrail end treatment, called TWINY, designed particularly for use with a thrie-beam guardrail system is developed. In the first phase, the system is designed and analyzed using a versatile, highly nonlinear finite-element analysis program LS-DYNA. Two different crashes involving a head on impact and a 15 S angle impact are simulated using LS-DYNA. In both simulations, a nominal 900 kg car traveling at 80 km/h is used to impact the end treatment as outlined in European Crash Testing Guidelines EN1317 section 4. Based on the successful simulation results, both tests are repeated in a crash test facility in Germany to substantiate simulation predictions. Full-scale crash testing results compared favorably with those obtained from LS-DYNA simulation. Based on the results, a final full-scale crash testing was carried out on the system to fully verify its compliance with the EN1317 section 4. A 1,300 kg compact car traveling at 80 km/ h impacted the end terminal at its midlength at an angle of 15 S. The vehicle is successfully redirected with minimal damage to both vehicle and terminal. Based on the simulation and full-scale crash test results, it can be concluded that TWINY is a promising end treatment for steel thrie-beam guardrail terminals and can be implemented at the European Highway System with confidence
In this paper, a finite element model of a 30,000 kg Heavy Goods Vehicle (HGV) was developed and validated against full-scale crash test data. Since this vehicle is a standard test vehicle in the European crash test standards, EN1317, development of an accurate vehicle model was deemed to be a positive contribution to the evaluation of roadside safety hardware. The vehicle model reproduces a FIAT-IVECO F 180 truck, a vehicle with four axles and a mass of 30,000 kg when fully loaded. The model consisted of 12,337 elements and 11,470 nodes and was built for and is ready to use with LS-DYNA finite element code from Livermore Software Technology Corporation. Data available from two previously performed full-scale crash tests, one on a steel bridge rail and the other on a portable concrete barrier, were used to validate the accuracy of the HGV model. Results of the finite element simulation study show that the developed HGV model shows promise and can accurately replicate the behaviour of an actual HGV in a full-scale crash test. Improvements such as the steering mechanism in the front axles and the suspension system are currently underway to make model more realistic
The use of roadside safety barriers in Italy has changed in recent years: the number of installed devices has increased, and so have their stiffness and resistance. These changes were necessary because early barrier design was inadequate to contain and redirect heavy vehicles. The change in barrier design led to an increase in stiffness and resistance; consequently, the action transferred to the structure by the device increased. The need for resistance on the bridge slabs can be too high because the peculiar action of the roadside barriers was not adequately taken into account in the oldest bridge design codes. In addition, characterizing the actions transferred to the bridge slab is difficult because of the dynamic nature of vehicle impacts on roadside barriers. Given the impossibility of performing a full-scale laboratory test for every bridge deck, the use of computational mechanics applied to dynamic impact/interaction problems is one of the best ways to establish these actions in the project phase. Research was conducted into the use of a three-dimensional finite element model of the bridge slab-barrier-vehicle system to perform a numerical simulation of the impact, according to the procedure used for the roadside barrier homologation crash test, described in the European Standard EN 1317.
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