search query: @keyword fracod / total: 4
reference: 4 / 4
« previous | next »
Author:Suikkanen, Johannes
Title:Modeling slope stability utilising fracture mechanics
Luiskan stabiliteetin rakomekaaninen mallintaminen
Publication type:Master's thesis
Publication year:2014
Pages:84 + 28      Language:   eng
Department/School:Insinööritieteiden korkeakoulu
Main subject:European Mining Course   (R3008)
Supervisor:Rinne, Mikael
Instructor:Antikainen, Juha
Electronic version URL: http://urn.fi/URN:NBN:fi:aalto-201403251640
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
Instructions

Reading digital theses in the closed network of the Aalto University Harald Herlin Learning Centre

In the closed network of Learning Centre you can read digital and digitized theses not available in the open network.

The Learning Centre contact details and opening hours: https://learningcentre.aalto.fi/en/harald-herlin-learning-centre/

You can read theses on the Learning Centre customer computers, which are available on all floors.

Logging on to the customer computers

  • Aalto University staff members log on to the customer computer using the Aalto username and password.
  • Other customers log on using a shared username and password.

Opening a thesis

  • On the desktop of the customer computers, you will find an icon titled:

    Aalto Thesis Database

  • Click on the icon to search for and open the thesis you are looking for from Aaltodoc database. You can find the thesis file by clicking the link on the OEV or OEVS field.

Reading the thesis

  • You can either print the thesis or read it on the customer computer screen.
  • You cannot save the thesis file on a flash drive or email it.
  • You cannot copy text or images from the file.
  • You cannot edit the file.

Printing the thesis

  • You can print the thesis for your personal study or research use.
  • Aalto University students and staff members may print black-and-white prints on the PrintingPoint devices when using the computer with personal Aalto username and password. Color printing is possible using the printer u90203-psc3, which is located near the customer service. Color printing is subject to a charge to Aalto University students and staff members.
  • Other customers can use the printer u90203-psc3. All printing is subject to a charge to non-University members.
Location:P1 Ark Aalto     | Archive
Keywords:slope stability
fracture mechanics
modeling
fracod
luiskan stabiliteetti
rakomekaniikka
mallinnus
fracod
Abstract (eng):The stability of slopes are commonly assessed in ways, which exclude the fractures of the rock mass, rather than including them as extending elements.
The failures of slopes have been noted to advance through internal flaws and failure zones of the rock mass, such as fractures.
By connecting these weakness zones with each other, a surface can be formed, which ultimately acts as a path of failure for the slope.
The reason for this study was to research an alternative approach, based on fracture mechanics, to model the stability of slopes.
The fracture propagation of a slope was approached by the means of numerical modeling, using a fracture mechanics code, Fracod2D.
The software was specifically developed to model the path of fracture propagation, under various thermal-, hydrological-, or time related conditions.
With the means to implement hydrological, and thermal coupling to the models, the slope stability could be assessed under the effect of temperatures affected by winter season, and ice ring expansion.

As a result of this study, a method for reducing the fracture toughness parameters KIC, and KIIC to represent the properties of rock mass was developed.
It was found out, that the effects of temperature change from winter season affect only the surface layer of the rock mass until the depth of 4m, depending on the thermal properties of the host rock.
Regarding the fracturing, it was found out that the fractures do not coalesce with each other, unless the distance between the fracture tips is of very small distance, compared to the model geometry.
In addition, once the process of fracturing itself has begun to occur, the process is very sensitive towards factors having an effect on the prevailing stress-field, such as water pressure and ice expansion.
Abstract (fin):Luiskan stabiliteetti analyysi suoritetaan useimmiten menetelmin, joissa rakojen kasvun vaikutus kalliomassan lujuuteen jätetään huomioimatta.
Kalliomassasta koostuvien luiskien sortumapintojen on huomattu muodostuvan heikkouksista kuten raoista tai rakovyöhykkeistä, jotka yhdistyessään mahdollistavat lopullisen luiskan sortuman.
Tämän tutkimuksen tarkoituksena on lähestyä luiskan stabiliteetin mallintamista rakomekaaniselta pohjalta, jolloin luiskan stabiliteetin menetys oletetaan tapahtuvan rakojen kasvusta johtuen.
Rakojen kasvun aiheuttamaa stabiliteetin muutosta tutkittiin numeerisesti mallintaen, käyttäen rakojen kasvun mallitamiseen erityisesti suunniteltua ohjelmaa nimeltään Fracod2D.
Fracod2D mahdollistaa rakojen kasvun mallintamisen erilaisten hydrologisten, termodynaamisten, sekä aikariippuvaisten kuormitusten alaisena.
Näiden ominaisuuksien avulla luiskan stabiliteettia pystyttiin analysoimaan talvesta johtuvan lämpötilan muutoksen, sekä siitä johtuvan jään lajenemisvaikutuksen aiheuttamasta lisätystä kuormasta.
Työn tuloksena kehitettiin menetelmä rakomekaanisten lujuusparametrien KIC, ja KIIC madaltamiseksi, mittakaavatekijän kasvaessa laboratorionäytteistä kohti kivimassaa.
Talvesta johtuva lämpötilaero sekä jään laajenemispaine vaikuttavat vain kallion pintakerroksissa, noin 4m syvyyteen.
Rakojen huomattiin yhdentyvän vain silloin, kun rakojen päät sijaitsevat hyvin lähellä toisiaan.
Mallinnuksissa selvisi, että luiskat eivät olleet herkkiä rakomekaanisien lujuusparametrien muutoksille.
Kun rakojen kasvua alkaa ilmetä, mallit tulevat erittäin herkiksi jännitystilan muutoksille, kuten jään- tai vedenpaineen aiheuttamaan jännitilan kasvuun.
ED:2014-04-06
INSSI record number: 48880
+ add basket
« previous | next »
INSSI