Ionuţ Radu Răcănel, Marian Daraban and Răzvan Stănescu
The carrying structure of the bridge over the Jiu River at Aninoasa consists in two parallel concrete arches with variable height of the cross section, sustaining a concrete deck through vertical concrete hangers. In the time period passed since the bridge was erected, some structural elements shown damages. In order to establish the technical state of the bridge, a technical appraisement was performed and according to this, the most exposed elements to the risk of failure are the hangers.
The purpose of this paper is to present briefly both, the method used to test the actual bridge carrying capacity in situ and the finite element model developed for the static and dynamic analysis of the structure.
In order to estimate the state of the structural elements, two ways were followed. In the first stage, a test project was carried out and in the second stage, a complete 3D finite element model was developed to analyze the bridge structure.
The test project has foreseen the loading of the bridge by heavy unloaded trucks, disposed in some positions on the deck and the measurements of the deck and arches displacements. The positions of the trucks were established in order to obtain the maximum values both for arches transverse displacements and vertical displacements of the deck. Using electro-resistive transducers the hangers elongations and strains values on their cross section were also measured. These measured values were compared with those obtained from the numerical calculations performed by using the complete finite element model. By means of the finite element model, also the response of the structure following the dynamic action of vehicles was investigated.
In Romania, with time, settlements located along the main roads have developed and transformed into linear towns, with significant local and connection traffic, important administrative, economic, commercial and touristic activities concentrated in the central area, as well as pedestrian traffic of over 200 pedestrians per hour in the main pedestrian crossings on the route.
The object of the present study is made by a series of junctions situated on National Road 1 in Busteni town, on a dangerous road sector. For this study, traffic measurements, simulations and suggestions for improving the existing situation were made.
Based on the simulated traffic flows, there were performed capacity analysis with PTV Vissim and Traficware Synchro softwares, and were developed appropriate planning solutions for the intersections, resulting in tables with extracted performance indicators based on micro simulation of the traffic values. Also planning solutions for horizontal design and proposals for traffic lights were made for junctions that can not operate under priority traffic on one direction or which are presenting traffic safety risk.
Based on the traffic data, it was taken in consideration the necessity to make planning proposals and to develop design solutions immediately applicable, with minimum intervention.
Solutions will refer to the geometric planning of the intersections, but with new plans and timings for traffic lights, including proposals for new equipment; regulating the traffic flow: development/ refurbishment of intersections and pedestrian crossings; optimization of routing programs in order to achieve a higher level of service and more efficient traffic control indicators; segregation of pedestrian movements by vehicles traffic, implementation of physical devices to lock / channel the traffic.
Transport demand forecast is a crucial parameter for transport planning. It defines the infrastructure dimensioning for a required level of service in a planning period, but moreover, it is determinative in the socioeconomic and financial feasibility study of transport projects. This paper presents the methodology and the results of the traffic flows forecasting exercise for the Pan-European Corridor X, which was elaborated to serve as a sound basis for documentation of the transport investments priorities, and the assessment of the results of the forecasted demand through comparisons with actual demand.