Helena Vrecl-Kojc (Author), Stanislav Škrabl (Author)

Abstract

Prispevek prikazuje modificiran prostorski porušni mehanizem za določitev 3D koeficienta pasivnega zemeljskega pritiska ob uporabi teorema zgornje vrednosti metode mejne analize. V analizi je upoštevan translatorni kinematično dopustni porušni mehanizem, ki je generaliziran z globino h = 1.0. Mehanizem geometrijsko predstavlja prostorski togi blok sestavljen iz osrednjega dela in dveh stranskih togih blokov, ki ju sestavljajo ovojnice bočnih trenjskih stožcev. Sprednja ploskev osrednjega dela mehanizma je v interakciji s podporno konstrukcijo, medtem, ko je zgornja ploskev lahko obremenjena z dodatno obtežbo. Bočni segmenti predstavljajo štiri ali tristrani mnogokotnik v prerezni ravnini z osrednjim delom, zaradi tega definirajo poligonalno drsino osrednjega dela. Na zunanji strani je vsak segment sestavljen iz infinitizimalno oddaljenih togih polstožcev, ki tvorijo ovojnico. Numerični rezultati mejnih vrednosti tridimenzionalnega (3D) pasivnega zemeljskega pritiska so predstavljeni v obliki brezdimenzijskega koeficienta Kpg kot posledica lastne teže zemljine ter Kpq zaradi dodatne površinske obtežbe. Namen raziskave je bil izboljšanje do sedaj najnižjih vrednosti rešitev pridobljenih po teoriji mejne analize. Rezultati analize predstavljenega modela so prikazani v grafični obliki v odvisnosti od geometrijskih parametrov in lastnosti temeljnih tal. V prispevku sta tudi predstavljena dva v svetovem merilu priznana prostorska porušna mehanizma, ki prav tako temeljita na metodi mejne analize ter primerjava rezultatov med vsemi tremi porušnimi mehanizmi.

Keywords

geomehanika;pasivni zemeljski pritisk;teorem zgornje vrednosti;optimiranje;tridimenzijski porušni mehanizem;soil mechanics;passive earth pressure;upper bound theorem;optimization;three-dimensional failure mechanism;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UM FGPA - Faculty of Civil Engineering, Transportation Engineering and Architecture
UDC: 624.131.3
COBISS: 11581462 Link will open in a new window
ISSN: 1854-0171
Parent publication: Acta geotechnica Slovenica
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Other data

Secondary language: Slovenian
Secondary title: Določitev pasivnega zemeljskega pritiska z uporabo tridimenzionalnega porušnega mehanizma
Secondary abstract: This paper presents a modified three-dimensional (3D) failure mechanism for determining the 3D passive earth pressure coefficient using the upper bound theorem within the framework of the limit analysis theory. The translational kinematically admissible failure mechanism generalized with a depth of h = 1.0 is considered in the analysis. The mechanism geometry presents a volume of rigid blocks composed of the central body and two lateral rigid bodies, which are connected by a common velocity field. The front surface of the central body interacts with the retaining wall, while the upper surface can be loaded by surcharge loading. The lateral body segments represent four- and three-sided polygons in the cross section of the central body; therefore, they define the polygonal failure surface of the central part. At the outer side, each segment of the lateral body is bounded by infinitesimally spaced rigid half-cones that describe the envelope of a family of half-cones. The numerical results of 3D passive earth pressure limit values are presented by non-dimensional coefficients of passive earth pressure influenced by the soil weight Kpg and a coefficient of passive earth pressure influenced by the surcharge Kpq. This research was intended to improve the lowest values obtained until now using the limit analysis theory. The results are presentedin a graphical form depending on the geometrical parameters and soil properties. A brief description of two world-recognized failure mechanisms based on the limit analysis approach, and the comparison of three failure mechanism results are also presented.
Secondary keywords: geomehanika;pasivni zemeljski pritisk;teorem zgornje vrednosti;optimiranje;tridimenzijski porušni mehanizem;
URN: URN:SI:UM:
Type (COBISS): Scientific work
Pages: str. 10-23
Volume: ǂVol. ǂ4
Issue: 1
Chronology: 2007
ID: 10935042