Evaluation of Liquefaction Potential on Alluvial Soils by Numerical Analysis and Effect of Soil Improvement on the Analysis

Selen Davran; Aşkın Özocak; Sedat Sert; Ertan Bol

Makale detayları

Evaluation of Liquefaction Potential on Alluvial Soils by Numerical Analysis and Effect of Soil Improvement on the Analysis

Yazarlar:

Selen Davran | Aşkın Özocak | Sedat Sert | Ertan Bol

Yayıncı:

Gazi University

Ana Başlıklar:

Mühendislik

Dergi:

Politeknik Dergisi Vol.27 Issue 3, pp.1029-1041

Belge Tipi:

Makale

Yayın Tarihi:

7/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001323374

pISSN:

2147-9429

Anahtar kelimeler:

Özet:

 During earthquakes, liquefaction-induced damages may occur in areas with soft alluvial soils. Therefore, this study deals with the evaluation of the liquefaction potential of a typical section representing the alluvial origin Adapazarı soils with the help of numerical analysis. The analyzes were carried out with Plaxis 2D software, and the soil section was modeled with the UBCSAND material model. In addition, in Adapazarı soil section with high liquefaction potential, the analyzes were repeated in order to determine the effect of soil improvement against liquefaction, in case of application of structural load and modeling of jet-grout columns under the structure. 1999 Marmara Earthquake was used as earthquake data. As a result of the analysis, certain analysis points were selected and the acceleration-time, displacement-time and pore water pressure changes at these points were examined. When the maximum acceleration values were examined at the mentioned analysis points, it was observed that there are soil amplifications due to the undamped liquefaction. In case of the displacement-time changes were examined, it was determined that the improvement reduced the horizontal displacements up to 59. In addition, in the absence of improvement, pore water pressures reach total stress and liquefaction occurs; in the case of improvement, it was observed that liquefaction was prevented since the pore water pressures did not reach the total stress. Based on the results, it was determined that whether the model represents liquefaction behavior should be discussed in more detail.

 During earthquakes, liquefaction-induced damages may occur in areas with soft alluvial soils. Therefore, this study deals with the evaluation of the liquefaction potential of a typical section representing the alluvial origin Adapazarı soils with the help of numerical analysis. The analyzes were carried out with Plaxis 2D software, and the soil section was modeled with the UBCSAND material model. In addition, in Adapazarı soil section with high liquefaction potential, the analyzes were repeated in order to determine the effect of soil improvement against liquefaction, in case of application of structural load and modeling of jet-grout columns under the structure. 1999 Marmara Earthquake was used as earthquake data. As a result of the analysis, certain analysis points were selected and the acceleration-time, displacement-time and pore water pressure changes at these points were examined. When the maximum acceleration values were examined at the mentioned analysis points, it was observed that there are soil amplifications due to the undamped liquefaction. In case of the displacement-time changes were examined, it was determined that the improvement reduced the horizontal displacements up to 59. In addition, in the absence of improvement, pore water pressures reach total stress and liquefaction occurs; in the case of improvement, it was observed that liquefaction was prevented since the pore water pressures did not reach the total stress. Based on the results, it was determined that whether the model represents liquefaction behavior should be discussed in more detail.

 During earthquakes, liquefaction-induced damages may occur in areas with soft alluvial soils. Therefore, this study deals with the evaluation of the liquefaction potential of a typical section representing the alluvial origin Adapazarı soils with the help of numerical analysis. The analyzes were carried out with Plaxis 2D software, and the soil section was modeled with the UBCSAND material model. In addition, in Adapazarı soil section with high liquefaction potential, the analyzes were repeated in order to determine the effect of soil improvement against liquefaction, in case of application of structural load and modeling of jet-grout columns under the structure. 1999 Marmara Earthquake was used as earthquake data. As a result of the analysis, certain analysis points were selected and the acceleration-time, displacement-time and pore water pressure changes at these points were examined. When the maximum acceleration values were examined at the mentioned analysis points, it was observed that there are soil amplifications due to the undamped liquefaction. In case of the displacement-time changes were examined, it was determined that the improvement reduced the horizontal displacements up to 59. In addition, in the absence of improvement, pore water pressures reach total stress and liquefaction occurs; in the case of improvement, it was observed that liquefaction was prevented since the pore water pressures did not reach the total stress. Based on the results, it was determined that whether the model represents liquefaction behavior should be discussed in more detail.

 Depremler sırasında yumuşak alüvyon zeminlerin bulunduğu bölgelerde sıvılaşma kaynaklı hasarlar meydana gelebilmektedir. Bu nedenle bu çalışma, alüvyon kökenli Adapazarı zeminlerini temsil eden tipik bir kesitin sıvılaşma potansiyelinin sayısal analiz yardımıyla değerlendirilmesini konu almaktadır. Analizler, Plaxis 2D yazılımı ile yürütülmüş, zemin kesiti ise UBCSAND malzeme modeli ile modellenmiştir. Ek olarak, sıvılaşma potansiyeli yüksek olan Adapazarı zemin kesitinde, zemin iyileştirmesinin sıvılaşmaya karşı etkisinin belirlenebilmesi adına, yapı yükü uygulanması halinde ve yapı altında jet-grout kolonlarının modellenmesi durumlarında analizler tekrar edilmiştir. Deprem verisi olarak 1999 Marmara Depremi kullanılmıştır. Yapılan analizler sonucunda belirli analiz noktaları seçilerek, bu noktalardaki ivme-zaman, deplasman-zaman ve boşluk suyu basıncı değişimleri incelenmiştir. Söz konusu analiz noktalarında maksimum ivme değerleri incelendiğinde, bazı noktalarda sıvılaşmanın sönümlenememesi ile zemin büyütmelerinin yaşandığı gözlemlenmiştir. Deplasman-zaman değişimlerinde ise iyileştirmenin yatay deplasmanları 59 değerine kadar azalttığı belirlenmiştir. Ek olarak, iyileştirmenin olmadığı durumda boşluk suyu basınçlarının toplam gerilmeye ulaştığı ve sıvılaşmanın gerçekleştiği; iyileştirme durumunda ise boşluk suyu basınçları toplam gerilmeye ulaşmadığından sıvılaşmanın önüne geçildiği gözlemlenmiştir. Sonuçlara dayanarak, modelin sıvılaşma davranışını temsil edip etmediğinin daha detaylı tartışılması gerektiği belirlenmiştir.

Makale detayları

Evaluation of Liquefaction Potential on Alluvial Soils by Numerical Analysis and Effect of Soil Improvement on the Analysis

Yazarlar:

Selen Davran | Aşkın Özocak | Sedat Sert | Ertan Bol

Yayıncı:

Gazi University

Ana Başlıklar:

Mühendislik

Dergi:

Politeknik Dergisi Vol.27 Issue 3, pp.1029-1041

Belge Tipi:

Makale

Yayın Tarihi:

7/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001323374

pISSN:

2147-9429

Jet-grout

liquefaction potential

UBCSAND model

soil improvementJet-grout

sıvılaşma potansiyeli

UBCSAND modeli

zemin iyileştirme

Sayı

Makale detayları

Yazarlar: Selen Davran | Aşkın Özocak | Sedat Sert | Ertan Bol

Yayıncı: Gazi University

Ana Başlıklar: Mühendislik

Dergi: Politeknik Dergisi Vol.27 Issue 3, pp.1029-1041

Belge Tipi: Makale

Yayın Tarihi: 7/2024

Belge Dili: Türkçe

Document ID (Org No.): 2001323374

pISSN: 2147-9429

Sayı

Yazarlar:

Selen Davran | Aşkın Özocak | Sedat Sert | Ertan Bol

Yayıncı:

Gazi University

Ana Başlıklar:

Mühendislik

Dergi:

Politeknik Dergisi Vol.27 Issue 3, pp.1029-1041

Belge Tipi:

Makale

Yayın Tarihi:

7/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001323374

pISSN:

2147-9429