Dynamic Response of a Single Pile Embedded in Sand Including the Effect of Resonance

In this paper, responses of a single pile embedded in sand soil (loose and dense) under dynamic loading (sinusoidal dynamic vibrations of 0.1 g to 0.5 g) have been investigated by two-dimensional analysis using the finite element method (FEM). Viscous (dashpot) boundaries have been used for taking the boundary effects of far-field into account. The applicability and accuracy of site responses of two-dimensional analysis due to the FEM modelling have been well verified with one-dimensional site responses. The results indicate that the relative density of sand (loose, dense) becomes prominent for the displacements of the pile, specifically under the frequency effects of resonance. While the pile in loose sand causes the displacements of 0.1 m to 0.5 m, the pile in dense sand leads to the displacements of 0.05 m to 0.25 m, proportionally with the dynamic loads from 0.1 g to 0.5 g. Moreover, the displacements reach their peak value at the frequency ratio of the resonance case. Viscous boundaries are found sufficient for modelling excessive displacements due to dynamic loading. However, the displacements reveal that high vibrations (> 0.1 g for loose sand, > 0.2 g for dense sand) influencing the pile deformations are critical for the issues of settlements. This is more significant for the resonance case in order for ensuring sufficient design. Consequently, the findings from the study are promising good contributions for pile design under the dynamic effect

3D Numerical Modeling of a Single Pipe Pile Under Axial Compression Embedded in Organic Soil

The objective of this paper is to numerically study the behavior pipe pile under axial compression embedded in organic soil has been numerically predicted. The pipe pile used in the study has been produced by steel and it has outer and inner diameters of 20 mm and 15 mm, respectively. The pile embedded in organic soil, which has the pile length ratios of 10, 20 and 30 (L/D), has been exposed to the axial load for different diameter ratios (d/D = 0, 0.25, 0.50 and 0.75). Numerical analyses have been performed by using Plaxis 3D computer program which is based on finite element method. The capability of the numerical analysis in the prediction of the load capacity of pipe pile has been studied. It has been understood that the results obtained from numerical analysis and experiment are in a good agreement, and then it has been observed in the parametric study that the load capacity of single pipe pile increases with the increase of the pile length and the wall thickness. © 2020, Springer Nature Switzerland AG

Investigation of the behaviour of single pile and pile groups under uplift load embedded in sand soil.

TEZ12284Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2019.Kaynakça (s. 203-209) var.XXV, 211 s. :_res. (bzs. rnk.), tablo ;_29 cm.Bu çalışmada, kum zemine gömülü tekil kazık ve kazık gruplarının çekme yükü etkisindeki davranışları deneysel ve sayısal olarak incelenmiştir. Deneylerde; kazık yüzeyi, kazık gömülme oranı (L/D) ve zemin sıkılığı (Dr) gibi parametrelerin çekme kapasitesi üzerindeki etkileri araştırılmıştır. İki farklı kazık yüzeyi (pürüzlü ve pürüzsüz) ve zemin sıkılığı (%30 ve %80) için kazıklar arası mesafe oranının (S/D) etkisi incelenmiş ve en büyük çekme yükü değerini veren optimum mesafe oranı belirlenmiştir. Ayrıca kazık grubundaki her bir kazığa yük hücresi bağlanarak kazık yerleşiminin çekme kapasitesini ne oranda değiştirdiğinin tespiti amaçlanmıştır. Çalışmada, sıkı kum zemine gömülü kazıkların PLAXIS 3D bilgisayar programı kullanılarak üç boyutlu sonlu elemanlar yöntemi ile sayısal çözümü yapılmıştır. Deneysel ve sayısal çalışmalardan elde edilen sonuçların uyumlu olduğu görülmüş ve çalışmanın sonucunda, araştırılan parametrelerin kazıkların çekme yükü üzerinde önemli bir etkiye sahip olduğu belirlenmiştir.In this study, the behaviour of single pile and pile groups embedded in sand soil under the uplift load have been investigated both experimentally and numerically. The effects of some variables such as pile surface, pile embedment ratio (L/D) and relative density of sand (Dr) on the uplift capacity have been studied in the experiments. The effect of the spacing ratio between piles (S/D) has been observed for two different pile surface (rough and smooth) and relative density of sand (30% and 80%), and then the optimum spacing ratio between piles, where the maximum uplift load value is reached, has been determined. Moreover, by connecting a load cell to each pile in the group, it is aimed to detect the extent to which the pile placement changes the uplift capacity. In the study, the piles embedded in dense sand soil have been analysed with the three-dimensional finite element method by using PLAXIS 3D computer software. It has been understood that the results obtained from the experimental and numerical studies are in a good agreement, and the results show that the investigated variables have a significant effect on the uplift load of the piles

Investigation of uplift behavior of group anchors.

TEZ10247Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2013.Kaynakça (s. 121-124) var.xvii, 125 s. : res. (bzs. rnk.), tablo ; 29 cm.Bu çalışmada, kum zeminlere gömülü ankraj plakalarının çekme kapasitesi model deneyler yapılarak araştırılmıştır. Deneylerde kare geometride ankraj plakaları kullanılmıştır. Model deneylerde, gömülme oranı, kum sıkılığı, ankrajlar arası mesafe ve yerleşim düzeni parametrelerinin çekme kapasitesi üzerindeki etkileri araştırılmıştır. Çalışmada ayrıca, kum zemine gömülü ankrajların, PLAXIS 3D Foundation bilgisayar programı kullanılarak, 3 boyutlu sonlu elemanlar yöntemi ile sayısal çözümü yapılmıştır. Elde edilen deneysel ve sayısal sonuçlar karşılaştırılarak temel mühendisliğinde kullanılmak üzere tasarım parametreleri önerilmiştir.PLAXIS 3D. In this study, uplift capacity of anchor plates embedded in sand was investigated by conducting model tests. Square shaped plate anchors were used in the tests. The parameters investigated are the uplift capacity of embedment ratio, density of sand, spacing between anchors and configuration. FE analysis of the test models were also carried out by using the FEM program, PLAXIS 3D Foundation. The numerical analysis were conducted under 3D. The results obtained from the numerical method are compared with the experimental values. After comparing the results of experiments and the numerical studies some practical design parameters were suggested for the relevant foundation engineering applications.Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir. Proje No: MMF2012YL21

Geogrid Donatılı Kumda Grup Ankraj Plakalarının Çekme Kapasitesinin İncelenmesi

Bu çalışmada, geogridle güçlendirilmiş ve güçlendirilmemiş kum zemindeki grup ankrajların çekme kapasitesi deneysel ve sayısal olarak incelenmiştir. Tek ve 2x2 yerleşim düzenindeki ankraj plakalarında gömülme oranı ve geogrid tabakası sayısının çekme kapasitesine etkisi araştırılırken, ankrajlar arası mesafe oranı, geogrid tabakasının ilk derinliği, geogrid tabakaları arası düşey mesafe ve geogrid tabakasının uzunluğu sabit tutulmuştur. Deneyler sonlu elemanlar programına dayalı Plaxis 3D bilgisayar programı ile sayısal olarak modellenmiş ve analiz edilmiştir. Deneysel çalışmalar ve sayısal analizlerden elde edilen sonuçlar karşılaştırılmış ve sayısal analizin ankraj plakasının çekme kapasitesini tahminindeki başarısı araştırılmıştır. Sonuç olarak, geogridle güçlendirmenin ankraj plakasının çekme kapasitesini 2 kata kadar artırdığı görülmüştür.In this study, the uplift capacity of group anchors has been investigated in sand with and without geogrid reinforcement experimentally and numerically. While the investigated parameters are the effect of embedment ratio of anchors and number of geogrid layers for a single anchor plate and 2x2 anchor configuration, the constant parameters are spacing ratio between anchors, depth of the first layer of geogrid, vertical spacing ratio of geogrid layers and length of geogrid. Experimental studies have been modelled and analyzed with Plaxis 3D which is a finite elements software. The results obtained from both of the studies have been compared and the validity of the numerical analysis has been investigated on the uplift capacity of anchor plate. As a result, it was shown that depending on the reinforcement geogrid, the uplift capacity of anchor plate can be improved by up to 2 times that of the unreinforced sand