Load transfer to piles due to the relative movement between the piles and the moving soil is a fa... more Load transfer to piles due to the relative movement between the piles and the moving soil is a fairly complex soil-pile interaction problem. Different analysis methods are available in literature to estimate the loads on piles. However, the predicted loads on the piles calculated by these methods vary due to insufficient representation of loading conditions and ignoring relative pile and soil movement. In this paper, three dimensional finite element analyses have been performed to evaluate the load transfer mechanism of free head passive pile groups in purely cohesionless soils. Numerical analyses are classified to address two most common passive pile cases, namely piles adjacent to embankments and piles used for slope stabilization. The effects of relative pile and soil displacement, pile spacing and pile arrangement on soil arching are investigated by numerical simulations. It is observed that load transfer decreases parallel to a decrease in pile spacing for piles adjacent to embankments contrary to piles used for slope stabilization.
Neogene aged units of a densely populated region of Western Turkey along the Aegean Sea coastline... more Neogene aged units of a densely populated region of Western Turkey along the Aegean Sea coastline is susceptible to landslides causing frequent economic loss especially following raining seasons. Several landslides took place in the area covering a narrow band of the coastline between Izmir and Soke (Aydin). Countermeasures against these relatively small-scale slope failures in the region often involve construction of either reinforced concrete retaining walls or stabilizing piles, which can be easily constructed by local contractors. In this study borings, in-situ and laboratory soil mechanics tests, geophysical and geological investigations have been performed in order to investigate the landslide occurred in the yard of an elementary school in Soke township. The analysis of two rows of piled retaining system constructed to reuse the school building against a potential slides are presented. Three inclinometer measurements have been performed after completion of the bored pile syst...
A catastrophic landslide following a rainy season occurred in the backyard of a school building i... more A catastrophic landslide following a rainy season occurred in the backyard of a school building in Söke, Turkey. The landslide caused property damage and adversely affected the present forest cover. Immediately after the landslide, double-row stabilizing piles were designed and constructed based on the findings of twodimensional (2D) finite element (FE) analyses to take an urgent precaution. To remedy the problem, pile displacements were monitored using inclinometers, and it was observed that the measured displacements were greater than the values calculated in the design stage. Accordingly, two different three-dimensional (3D) numerical FE models were used in tandem with the inclinometer data to determine the load transfer mechanism. In the first model, numerical analyses were made to predict the pile displacements, and while the model predicted successfully the displacement of the piles constructed in the middle with reasonable accuracy, it failed for the corner piles. In the second model, the soil load transfer between piles was determined considering the sliding mass geometry, the soil arching mechanism and the group interaction between adjacent piles. The results of the second model revealed that the middle piles with large displacements transferred their loads to the corner piles with smaller displacements. The generated soil loads, perpendicular to the sliding direction, restricted pile deformations and piles with less displacement were subjected to greater loads due to the bowl-shaped landslide. A good agreement between the computed pile displacements and inclinometer data indicates that the existing soil pressure theories should be improved considering the position of the pile in the sliding mass, the depth and deformation modulus of stationary soil, the relative movement between the soil and piles and the relative movement of adjacent piles.
In this study, 3D finite element analysis is carried out to investigate the behavior of single pi... more In this study, 3D finite element analysis is carried out to investigate the behavior of single pile and a group of free-head piles subjected to lateral soil movements. The mobilization mechanism of resistance from passive pile groups is discussed from the standpoint of the arching effect. Lateral pressure distributions along piles that vary with pile spacing, interface roughness and relative displacement between the pile and soil are determined. Computational simulations are adopted to consider the effect of pile spacing and the variation of internal friction angle on the lateral response of a pile in a row in cohesionless soil. It is observed that the loads acting on the piles increase with increasing of the pile spacing due to soil arching which is not effective after larger spacing than 8d. It is also revealed that the acting loads arrive at the maximum value and remain constant when the relative displacement exceeds 1.2 fold pile diameter.
Page 1. 405 Limit State Moment Functions for Laterally Loaded Single Piles in Local OC Clay Aşırı... more Page 1. 405 Limit State Moment Functions for Laterally Loaded Single Piles in Local OC Clay Aşırı Konsolide Kil Zeminlerdeki Yanal Yüklü Kazıklar için Limit Durum Moment Fonksiyonları Gökhan İMANÇLI*, Mehmet Rifat KAHYAOĞLU ve Gürkan ÖZDEN ...
Slope reinforcement using piled structures is one of the most appropriate methods for preventing ... more Slope reinforcement using piled structures is one of the most appropriate methods for preventing slope movements. The prediction of loads acting on piles is important in order to properly design of slope stabilizing piles. Despite, different uncoupled analysis methods to estimate the loads on piles are available in literature; the loads acting on piles predicted using these methods may differ depending on soil-pile interaction and loading conditions. Comprehensive experimental works are needed in order to ensure the reliability of these analytical methods. In this study, the simulations of designed experiment for determining the load acting on the flexible piles were performed via two dimensional finite element methods. The parametric study was carried out to determine the effects of the center to center pile spacing on the load transfer behavior. Corresponding to the numerical results, the load acting on the flexible piles was investigated.
A key parameter in the design of a laterally loaded pile is the determination of its performance ... more A key parameter in the design of a laterally loaded pile is the determination of its performance level. Performance level of a pile is usually expressed as the maximum head deflection and bending moment. In general, uncertainties in the performance of a pile originates from many factors such as inherent variability of soil properties, inadequate soil exploration programs, errors taking place in the determination of soil parameters, limited calculation models as well as uncertainties in loads. This makes it difficult for practicing engineers to decide for the reliability of laterally loaded piles both in cohesive and cohesionless soils. In this paper, limit state functions and consequent performance functions are obtained for single concrete piles to predict the maximum bending moment, a widely accepted design criterion along with the permissible pile head displacement. Analyses were made utilizing three dimensional finite element method and soil-structure-interaction (SSI) effects w...
Load transfer to piles due to the relative movement between the piles and the moving soil is a fa... more Load transfer to piles due to the relative movement between the piles and the moving soil is a fairly complex soil-pile interaction problem. Different analysis methods are available in literature to estimate the loads on piles. However, the predicted loads on the piles calculated by these methods vary due to insufficient representation of loading conditions and ignoring relative pile and soil movement. In this paper, three dimensional finite element analyses have been performed to evaluate the load transfer mechanism of free head passive pile groups in purely cohesionless soils. Numerical analyses are classified to address two most common passive pile cases, namely piles adjacent to embankments and piles used for slope stabilization. The effects of relative pile and soil displacement, pile spacing and pile arrangement on soil arching are investigated by numerical simulations. It is observed that load transfer decreases parallel to a decrease in pile spacing for piles adjacent to embankments contrary to piles used for slope stabilization.
Neogene aged units of a densely populated region of Western Turkey along the Aegean Sea coastline... more Neogene aged units of a densely populated region of Western Turkey along the Aegean Sea coastline is susceptible to landslides causing frequent economic loss especially following raining seasons. Several landslides took place in the area covering a narrow band of the coastline between Izmir and Soke (Aydin). Countermeasures against these relatively small-scale slope failures in the region often involve construction of either reinforced concrete retaining walls or stabilizing piles, which can be easily constructed by local contractors. In this study borings, in-situ and laboratory soil mechanics tests, geophysical and geological investigations have been performed in order to investigate the landslide occurred in the yard of an elementary school in Soke township. The analysis of two rows of piled retaining system constructed to reuse the school building against a potential slides are presented. Three inclinometer measurements have been performed after completion of the bored pile syst...
A catastrophic landslide following a rainy season occurred in the backyard of a school building i... more A catastrophic landslide following a rainy season occurred in the backyard of a school building in Söke, Turkey. The landslide caused property damage and adversely affected the present forest cover. Immediately after the landslide, double-row stabilizing piles were designed and constructed based on the findings of twodimensional (2D) finite element (FE) analyses to take an urgent precaution. To remedy the problem, pile displacements were monitored using inclinometers, and it was observed that the measured displacements were greater than the values calculated in the design stage. Accordingly, two different three-dimensional (3D) numerical FE models were used in tandem with the inclinometer data to determine the load transfer mechanism. In the first model, numerical analyses were made to predict the pile displacements, and while the model predicted successfully the displacement of the piles constructed in the middle with reasonable accuracy, it failed for the corner piles. In the second model, the soil load transfer between piles was determined considering the sliding mass geometry, the soil arching mechanism and the group interaction between adjacent piles. The results of the second model revealed that the middle piles with large displacements transferred their loads to the corner piles with smaller displacements. The generated soil loads, perpendicular to the sliding direction, restricted pile deformations and piles with less displacement were subjected to greater loads due to the bowl-shaped landslide. A good agreement between the computed pile displacements and inclinometer data indicates that the existing soil pressure theories should be improved considering the position of the pile in the sliding mass, the depth and deformation modulus of stationary soil, the relative movement between the soil and piles and the relative movement of adjacent piles.
In this study, 3D finite element analysis is carried out to investigate the behavior of single pi... more In this study, 3D finite element analysis is carried out to investigate the behavior of single pile and a group of free-head piles subjected to lateral soil movements. The mobilization mechanism of resistance from passive pile groups is discussed from the standpoint of the arching effect. Lateral pressure distributions along piles that vary with pile spacing, interface roughness and relative displacement between the pile and soil are determined. Computational simulations are adopted to consider the effect of pile spacing and the variation of internal friction angle on the lateral response of a pile in a row in cohesionless soil. It is observed that the loads acting on the piles increase with increasing of the pile spacing due to soil arching which is not effective after larger spacing than 8d. It is also revealed that the acting loads arrive at the maximum value and remain constant when the relative displacement exceeds 1.2 fold pile diameter.
Page 1. 405 Limit State Moment Functions for Laterally Loaded Single Piles in Local OC Clay Aşırı... more Page 1. 405 Limit State Moment Functions for Laterally Loaded Single Piles in Local OC Clay Aşırı Konsolide Kil Zeminlerdeki Yanal Yüklü Kazıklar için Limit Durum Moment Fonksiyonları Gökhan İMANÇLI*, Mehmet Rifat KAHYAOĞLU ve Gürkan ÖZDEN ...
Slope reinforcement using piled structures is one of the most appropriate methods for preventing ... more Slope reinforcement using piled structures is one of the most appropriate methods for preventing slope movements. The prediction of loads acting on piles is important in order to properly design of slope stabilizing piles. Despite, different uncoupled analysis methods to estimate the loads on piles are available in literature; the loads acting on piles predicted using these methods may differ depending on soil-pile interaction and loading conditions. Comprehensive experimental works are needed in order to ensure the reliability of these analytical methods. In this study, the simulations of designed experiment for determining the load acting on the flexible piles were performed via two dimensional finite element methods. The parametric study was carried out to determine the effects of the center to center pile spacing on the load transfer behavior. Corresponding to the numerical results, the load acting on the flexible piles was investigated.
A key parameter in the design of a laterally loaded pile is the determination of its performance ... more A key parameter in the design of a laterally loaded pile is the determination of its performance level. Performance level of a pile is usually expressed as the maximum head deflection and bending moment. In general, uncertainties in the performance of a pile originates from many factors such as inherent variability of soil properties, inadequate soil exploration programs, errors taking place in the determination of soil parameters, limited calculation models as well as uncertainties in loads. This makes it difficult for practicing engineers to decide for the reliability of laterally loaded piles both in cohesive and cohesionless soils. In this paper, limit state functions and consequent performance functions are obtained for single concrete piles to predict the maximum bending moment, a widely accepted design criterion along with the permissible pile head displacement. Analyses were made utilizing three dimensional finite element method and soil-structure-interaction (SSI) effects w...
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