| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

Show document Help

Title:The response of saturated soils to a dynamic load
Authors:ID Lenart, Stanislav (Author)
ID Fakulteta za gradbeništvo, prometno inženirstvo in arhitekturo Univerze v Mariboru (Copyright holder)
Files:.pdf Acta_geotechnica_Slovenica_2008_Lenart_The_response_of_saturated_soils_to_a_dynamic_load.pdf (370,70 KB)
MD5: 805951F03D9548581516944A683A92EA
PID: 20.500.12556/dkum/c6c799aa-5a0b-4c66-ab57-69c4d3b3233e
 
URL http://fgserver3.fg.um.si/journal-ags/2008-1/article-3.asp
 
Language:English
Work type:Scientific work
Typology:1.01 - Original Scientific Article
Organization:FGPA - Faculty of Civil Engineering, Transportation Engineering and Architecture
Abstract:This paper presents the two most significant types of deformation behavior fordynamically loaded, saturated soil. Flow liquefaction and cyclic mobility deserve special attention because of the large deformations that accompany these two phenomena. The submergence of a railway-line embankment due to the newly built Sava-river accumulation reservoir in Boštanj and the large landslide that occurred in the Stože area in the Julian Alps are case histories in Slovenia where flow liquefaction and cyclic mobility were analyzed. The dynamic loading caused by railway traffic and possible seismic activity were taken into account. Material from these two sites, silty sand and lacustrine carbonate silt, were used in extensive laboratory research, with the objective to define a procedure for excess pore-water pressure-generation modeling in dynamically loaded saturated soil. It has been found recently that the change of the pore-water pressure is related to the dissipated energy density calculated from the hysteresis loops caused by dynamic loading. Based on the experimental results an empirical equation defining the generation of pore pressure during dynamic loading has been proposed. The equation is divided into two parts: the first part describing the residual pore-water pressure generation, and the second part describing the increment and decrement of pore-water pressure within the load cycle, the so-called temporary pore-water pressure change. The proper effective stresses and thus the stress path of the dynamically loaded soil can be defined by using the proposed energy-based numerical model. The proposed pore-pressure model can also be used in deformation-behavior modeling. It was observed from the experimental results that after a few cycles of dynamic loading the saturated soil starts to exhibit a very low stiffness at the beginning of a load cycle, after which it begins to strengthen. The strain developed during this softening phase represents the main share of the total strain. The occurrence and duration of this phase are related to the energy dissipated during the cyclic loading as well, and the relation between the dissipated energy, the excess pore pressure and the short-term flow during cyclic mobility, give us an opportunity for a simple response modeling of the dynamically loaded saturated soils.
Keywords:flow liquefaction, cyclic mobility, excess pore pressure, dissipated energy
Publication status:Published
Publication version:Version of Record
Year of publishing:2008
Number of pages:str. 36-49
Numbering:Letn. 5, št. 1
PID:20.500.12556/DKUM-70658 New window
ISSN:1854-0171
UDC:624
ISSN on article:1854-0171
COBISS.SI-ID:1432167 New window
NUK URN:URN:SI:UM:DK:UUFRCFJ4
Copyright:Fakulteta za gradbeništvo, prometno inženirstvo in arhitekturo Univerze v Mariboru
Publication date in DKUM:05.06.2018
Views:1106
Downloads:230
Metadata:XML DC-XML DC-RDF
Categories:Misc.
:
Copy citation
  
Average score:(0 votes)
Your score:Voting is allowed only for logged in users.
Share:Bookmark and Share


Hover the mouse pointer over a document title to show the abstract or click on the title to get all document metadata.

Record is a part of a journal

Title:Acta geotechnica Slovenica
Shortened title:Acta geotech. Slov.
Publisher:Fakulteta za gradbeništvo, prometno inženirstvo in arhitekturo Univerze v Mariboru
ISSN:1854-0171
COBISS.SI-ID:215987712 New window

Secondary language

Language:Slovenian
Title:Odziv zasičenih zemljin na dinamično obremenitev
Abstract:V članku sta predstavljena dva najbolj izrazita načina deformiranja dinamično obremenjenih zasičenih zemljin. Likvifakcija s tečenjem in ciklična mobilnost sta pojava, ki pritegneta posebno pozornost zaradi velikih deformacij, ki ju spremljajo. Potopitev nasipa železniške proge zaradi novozgrajenega akumulacijskega bazena na reki Savi v Boštanju in velik plaz, ki se je sprožilna področju Stože v Julijskih Alpah predstavljata študiji primerov v Sloveniji, kjer sta bili analizirani tudi likvifakcija s tečenjem in ciklična mobilnost. Upoštevana je bila dinamična obremenitev zaradi železniškega prometa in morebitne potresne obtežbe. Materiali iz obeh lokacij: meljni pesek in prodnato-peščeni melj, so bili uporabljeni v obsežnih laboratorijskih preiskavah, katerih namen je bil določiti postopek za modeliranje generiranja dodatnega pornega pritiska v dinamično obremenjenih z vodo zasičenih zemljinah. Novejše ugotovitve kažejo, da je sprememba pornega tlaka povezana s količino disipirane energije, ki jo določajo histerezne zanke dobljene z dinamičnim obremenjevanjem. Na osnovi eksperimentalnih rezultatov je bila predlagana enačba za empirično zvezo, ki definira generiranje pornega tlaka med dinamičnim obremenjevanjem. Enačba je sestavljena iz dveh delov, prvi opisuje generiranje nepovratnih sprememb pornega tlaka, drugi del pa opisuje prirastke in upade tlaka porne vode znotraj enega obremenjevalnega cikla, ti. povratne spremembe pornega tlaka. Z uporabo predlaganega energijskega numeričnega modela je mogoče določiti dejanske efektivne napetosti in s tem napetostno pot dinamično obremenjene zemljine. Predlagani model za porne tlake se lahko uporabi tudi za modeliranje deformacijskega obnašanja. Z eksperimenti je bilo ugotovljeno, da ima dinamično obremenjena zemljina po nekaj ciklih obtežbe na začetku cikla zelo nizko togost, ki pa se kasneje poveča. Deformacija, ki se razvije za časa trajanja te podajne faze zemljine, predstavlja glavnino deleža skupne deformacije. Pojav in trajanje te faze sta prav tako povezana z energijo, ki se disipira med cikličnim obremenjevanjem. Odnos med disipirano energijo in dodatnim pornim tlakom ter kratkotrajnim tečenjem med pojavom ciklične mobilnosti, omogoča preprosto modeliranje odzivadinamično obremenjenih zasičenih zemljin.
Keywords:likvifakcija s tečenjem, ciklična mobilnost, dodatni porni tlak, disipirana energija


Collection

This document is a part of these collections:
  1. Acta geotechnica Slovenica

Comments

Leave comment

You must log in to leave a comment.

Comments (0)
0 - 0 / 0
 
There are no comments!

Back
Logos of partners University of Maribor University of Ljubljana University of Primorska University of Nova Gorica