Abstract

geosynthetic, reinforced, piled embankment is an effective and economic method to solve the problems of possible bearing failure, unacceptable settlement and slope instability for an embankment built over soft soil this has led to its widespread use, especially for high-speed railway embankments. Some design methods have been developed to assess the performance of these reinforced structures, which are mainly based on the results from small-scale models and numerical simulations. However, the reliability of these methods needs to be validated under full-scale field tests. This paper presents a numerical and analytical study for a full-scale field test of the Fengyang high-speed railway embankment. The results were analyzed and discussed in terms of the settlement of subsoil, the stressconcentration ratio (SCR), the axial force and the frictional stress of the pile. They showed that the settlement of the subsoil, from both the finite-element method (FEM) and the analytical method, were in good agreement with the measurement, and thus was a reliable parameter to assess the performance of the piled embankment with reasonable accuracy. The SCR was overestimated by the modified Terzaghi method, with a difference of 25%, while it was underestimated by the FEM, with a difference of approximately 20%. It was also shown that the tensile force in the reinforcement could be effectively assessed using the proposed analytical method, while it was overestimated by the FEM with a difference of 44%. Z geosintetiki ojačan pilotni nasip predstavlja učinkovito in gospodarno metodo za reševanje težav glede nosilnosti temeljnih tal in nesprejemljivih posedkov ter nestabilnosti brežin nasipov zgrajenih na mehkih tleh, kar vodi do široke uporabe, zlasti za nasipe železnic visokih hitrosti. Razvite so bile nekatere metode projektiranja za ocenjevanje uspešnosti teh ojačanih konstrukcij, ki v glavnem temeljijo na rezultatih iz modelov v zmanjšanem merilu in numeričnih simulacij. Zanesljivost teh metod mora biti preverjena s terenskimi preizkusi v naravni velikosti. V članku je predstavljena numerična in analitična študija na terenskem preizkusu v naravni velikosti, in sicer, na nasipu za železnico visokih hitrosti Fengyang. Rezultati so bili analizirani in komentirani za posedke zemljine, razmerje koncentracije napetosti (RKN), osno silo in trenjsko napetost v pilotu. Pokazalo se je, da so rezultati posedkov dobljeni z metodo končnih elementov (MKE) in analitično metodo bili zelo blizu merjenim, in to je bil zanesljiv parameter, da bo ocenitev obnašanja s piloti ojačanega nasipa sprejemljivo natančna. RKN je bil po modificirani Terzaghijevi metodi precenjen za 25%, medtem, ko je bil po MKE podcenjen za približno 20%. Pokazano je bilo tudi, da bi se natezna sila v ojačitvi lahko učinkovito ocenila s predlagano analitično metodo, medtem ko je bila s FEM precenjena za 44%.

Abstract

Traffic is the most widespread source of environmental noise. Railway noise has become increasingly common in urban areas in the past few decades. Therefore environmental requirements for railway operations regarding noise are becoming very strict and will become even tighter in future. In the present paper we present actual track- based field test performed on Slovenian Railways. The significant noise reduction (up to 30dBA) was achieved by the application of CHFC material on the rail using CL-E1 top anti noise system. Der Verkehr ist die am weitesten verbreitete Quelle von Umgebungslärm. Eisenbahnlärm nahm in den letzten Jahrzehnten in städtischen Gebieten immer mehr zu. Aus diesem Grund wurden die Umweltanforderungen für den Bahnverkehr bezüglich des Lärms immer strenger und werden in der Zukunft noch höher. In der vorliegenden Arbeit stellen wir den tatsächlichen Track-basierten Feldversuch auf der Slowenischen Bahn dar. Die deutliche Lärmreduzierung (bis 30 dBA)wurde durch die Anwendung von CHFC-Material auf der Schiene mithilfe des Cl-E1 Antirauschsystems erreicht. Document type: Article

Abstract

The paper deals with the estimation of demand functions for services of publicrailway passenger transportation in the case of Slovenia. Six demand functions were selected and separately interpreted. The aggregate values of demand elasticities reported in this paper suggest that the railway passenger demand is price and income inelastic. Coefficients of income elasticity below unity show that the services of railway passenger transportation in Slovenia can be classified among normal goods. A hypothetical increase in average real fares leads to a percentage decrease in the number of passengers traveling by rail that is smaller than the percentage increase in fares. The estimated price elasticities imply that, in the short run, there is potential for improving revenues of the railway operator by increasing average real fares. Prispevek se ukvarja z ocenjevanjem funkcij povpraševanja po storitvah železniškega potniškega prometa v primeru Slovenije. V procesu selekcije je bilo izbranih šest agregatnih funkcij, katerih ocene posebej navajamo in komentiramo. Iz ocen funkcij izhaja, da je povpraševanje po storitvah železniškega potniškega prometa cenovno in dohodkovno neelastično. Koeficientidohodkovne elastičnosti povpraševanja manjši od ena kažejo, da je moč prevoze v notranjem železniškem prometu za povprečnega kupca storitev železniškega potniškega prometa v Sloveniji uvrstiti med normalne dobrine. V primeru povečanja povprečnih realnih voznin se število prepeljanih potnikov naželeznici zmanjša odstotno za manj kot znaša odstotni dvig voznin. Evidentirana cenovna neelastičnost povpraševanja nas navaja k sklepu, da se prihodki operaterja notranjega železniškega prometa pri zviševanju povprečne realne voznine povečujejo.