Yazar "Ertugrul, Ozgur L." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Effect of dilatancy on tension response of completely rough piles embedded in granular soils
    (Pergamon-Elsevier Science Ltd, 2024) Tolun, Mustafa; Emirler, Buse; Ertugrul, Ozgur L.; Yildiz, Abdulazim
    Pile surface roughness is an important characteristic determining the displacement response of piles under various loading conditions since it leads to surface friction resistance. Considering that no capacity contribution is acquired from the pile tip, the effect of surface friction becomes more pronounced for tension piles. Pile surfaces can be classified as smooth, rough, or completely rough according to the normalized surface roughness value (Rn) of piles, and this paper focuses only on the uplift capacity of piles with normalized surface roughness values greater than 0.1 (i.e., completely rough) by employing the PLAXIS3D code verified against results of twelve physical modelling tests reported in the literature. The reason of selecting piles with completely rough surfaces in this study is that dilatancy behaviour can be only observed in the uplift load-displacement relationships of such piles, unlike the piles with smooth or rough surfaces. While numerical simulations are repeated for different normalized surface roughness values (Rn = 0.2, 0.5, 1.0, and 2.0) and different relative densities of sandy backfill (Dr = 25%, 50%, and 75%), the effect of the pile surface friction resistance on the uplift capacity, which occurs as a result of the interaction between the pile surface and sandy soil grains, is studied with special emphasis on soil dilatancy. It is observed that the numerical results are quite compatible with the physical test results. In addition, increasing the pile surface roughness and relative density of sandy soil causes an increase in the uplift capacity, and those capacity increments can only be modelled properly by increasing the dilatancy angle of sandy soil in finite element analyses.
  • [ X ]
    Öğe
    Effect of surface roughness characteristics on the uplift capacity of piles: A physical modelling study
    (Taylor & Francis Inc, 2023) Tolun, Mustafa; Emirler, Buse; Ertugrul, Ozgur L.; Yildiz, Abdulazim
    Pile surface roughness is one of the significant variables affecting the load-bearing capacity of piles. Especially for piles subjected to uplift loads, this parameter can be considered as the main factor that affects the uplift capacity since there is no contribution originating from the pile tip. According to limited previous research, a pile surface can be evaluated as smooth if pile surface roughness parameter (R-n) is less than 0.02, whereas the pile surface is considered completely rough when R-n value is greater than 0.10. This paper, therefore, is aimed to investigate the validity and effectiveness of the numerical limits previously suggested for R-n and intends to determine the relationship between R-n and soil-pile friction angle. For this purpose, laboratory model tests were performed on 12 small-scale pile models embedded in cohesionless soils having varying densities (D-r=25%, 50%, and 75%). Pile surfaces were specially textured to produce different surface roughness values from 0 to 2. Test results indicated that increasing the relative density of cohesionless soil and the pile surface roughness had a considerable contribution to the uplift capacity and soil-pile friction angle. Furthermore, some typical values of R-n like 0, 0.04, and 0.10 were found to be critical for pile uplift behaviour and capacity, and R-n value should be accepted as zero to consider the pile surface as completely smooth.