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%.