Civil Engineering / İnşaat Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/13

Browse

Filters

2021 - 20222

Settings

Author: search.filters.author.Ecemiş, NurhanPublisher: search.filters.publisher.Elsevier

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 21
    Citation - Scopus: 23
    Soil Liquefaction-Induced Uplift of Buried Pipes in Sand-Granulated Mixture: Numerical Modeling
    (Elsevier, 2022) Valizadeh, Hadi; Ecemiş, Nurhan
    The significant uplift of buried pipes observed during recent earthquakes has showed the need for further research in remediation methods for soil liquefaction. Sand-granulated rubber mixture is reported as a new soil improvement method that can be applied as a liquefaction mitigation filling material around buried pipe. In this study, the effects of pipe size, burial depth, and shaking intensity on the pipe uplift and the liquefaction potential of the sand-tire derived granulated rubber mixture placed around the buried pipes were investigated using numerical models. First, the result of 1-g shaking table tests was used for the verification of the numerical analysis. Comparing the numerical results and the experimental measurements showed that the numerical simulation using the UBCSAND constitutive model could accurately estimate the liquefaction-induced uplift of the buried pipes as well as the related failure. Then, a parametric study was conducted to investigate the effects of the pipe diameter, the pipe depth, and the value of the acceleration on pipe uplift and liquefaction potential when the SGR mixture was placed as filling material. Eventually, an analytical formula was proposed to estimate the liquefaction-induced uplift of buried pipes, and the soil failure mode was categorized according to the pipe's burial depth ratio.
  • Article
    Citation - WoS: 39
    Citation - Scopus: 44
    Experimental and Numerical Modeling on the Liquefaction Potential and Ground Settlement of Silt-Interlayered Stratified Sands
    (Elsevier, 2021) Ecemiş, Nurhan
    Recent seismic events indicate that the simplified liquefaction-evaluation procedures are incapable of depicting general trends in liquefaction damage for stratified sands interlayered with silts. The conditions and mechanisms affecting the liquefaction potential of stratified sands exist in the field and ground settlement after liquefaction remain poorly understood. This work aims to investigate the seismic response of nonhomogeneous soil deposits by large-scale model tests and numerical simulations using an advanced constitutive model. A comprehensive experimental program was undertaken in which a total of three shake-table tests were performed on uniform sand and two stratified-sand deposits interlayered with different thicknesses of silt to investigate the ground settlement and distribution and dissipation of excess pore pressure during and after shaking. The shake-table test results and the numerical simulations of the silt-interlayered stratified sands, first indicate that the thickness of the silt seam has a significant influence on the liquefaction resistance of stratified-sand deposits beneath the silt layer. The second conclusion of this study reveals that the thickness and coefficient of consolidation of the silt and the liquefied sand below the silt layer significantly alter the degree of dissipation after the shake, and this causes different deformation/settlement at the ground surface. Therefore, there will be probably inaccuracies in applying simplified liquefaction evaluation procedures to the actual soil profile characterized by various patterns of layering in the field.