Group interaction effects on laterally loaded piles in clay.
01 Apr 2010-Journal of Geotechnical and Geoenvironmental Engineering (American Society of Civil Engineers)-Vol. 136, Iss: 4, pp 573-582
TL;DR: In this article, the results of static lateral load tests carried out on 1×2, 2×2, 1×4, and 3×3 model pile groups embedded in soft clay are presented.
Abstract: This paper presents the results of static lateral load tests carried out on 1×2 , 2×2 , 1×4 , and 3×3 model pile groups embedded in soft clay. Tests were carried out on piles with length to diameter ratios of 15, 30, and 40 and three to nine pile diameter spacing. The effects of pile spacing, number of piles, embedment length, and configuration on pile-group interaction were investigated. Group efficiency, critical spacing, and p multipliers were evaluated from the experimental study. The experimental results have been compared with those obtained from the program GROUP. It has been found that the lateral capacity of piles in 3×3 group at three diameter spacing is about 40% less than that of the single pile. Group interaction causes 20% increase in the maximum bending moment in piles of the groups with three diameter spacing in comparison to the single pile. Results indicate substantial difference in p multipliers of the corresponding rows of the linear and square pile groups. The predicted field group be...
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Journal Article•
TL;DR: In this article, a large-scale group of steel pipe piles and an isolated single pile were subjected to two-way cyclic lateral loading in a submerged firm to dense sand that was placed and compacted around the piles.
Abstract: A large‐scale group of steel pipe piles and an isolated single pile were subjected to two‐way cyclic lateral loading. The tests were conducted in a submerged firm to dense sand that was placed and compacted around the piles. All of the piles were extensively instrumented so that the variation in soil resistance within the group could be determined. The response of the piles in the group was also compared with the response of the isolated single pile. The loss of efficiency of the piles in the group was related principally to “shadowing” (i.e., the loss of soil resistance of piles in the trailing rows). Piles in the leading row supported a large proportion of the group load and behaved similarly to the isolated single pile. Two‐way cyclic loading had little effect on the distribution of load to the piles in the group, but tended to densify the sand around both the single pile and the group piles.
42 citations
TL;DR: In this paper, a series of seismic centrifuge model tests were performed to study the behavior of pile groups in soft kaolin clay, and several small-scale pile-raft models were fabricated, ranging from a 2×1 to a 4×3 pile group.
40 citations
TL;DR: In this article, the authors investigated the behavior of laterally loaded pile groups with a rigid head and correlated the response of a pile group to that of a single pile in clayy soils.
Abstract: The aim of this paper is to investigate the behaviour of laterally loaded pile groups with a rigid head, and correlate the response of a pile group to that of a single pile. For this purpose, a computationally intensive study using three-dimensional non-linear numerical analysis was carried out for different pile group arrangements in clayey soils. The responses of the pile groups were compared with that of the single pile, and the variation of the displacement amplification factor Ra was then quantified. The influence of the number of piles, the spacing and the deflection level on the group response is discussed. A previously proposed relationship for predicting the response of a pile group, based on its configuration and the response of a single pile, has been modified to allow for soil shear strength that was found to affect the group response. The modified relationship provides a reasonable prediction for various group configurations in clayey soils.
38 citations
TL;DR: In this article, the results of static lateral load test carried out on a single aluminium model pile embedded in soft clay (consistency index, Ic 0.42) on a sloping ground.
Abstract: This paper presents the results of static lateral-load test carried out on a single aluminium model pile embedded in soft clay (consistency index, Ic = 0.42) on a sloping ground. A series of laboratory model tests had been carried out on the instrumented aluminium pile with outer diameter of 25.46 mm on a sloping ground of varying slopes (1V:1H, 1V:1.5H, 1V:2H, 1V:3H and 1V:5H) and with varying embedment length-to-diameter ratio (L/D) of 20, 25 and 30. To quantify the effect of slopes, the tests were also carried out on a horizontal ground surface. From the experimental results, the lateral load-carrying capacity of the pile, load–deflection response of the pile at pile head, effect of slopes and embedment length on pile capacity and bending-moment profile along the pile shaft were studied. The experimental results have been compared with those obtained from finite element analysis PLAXIS 3D and found to be in good agreement.
38 citations
Cites background or methods from "Group interaction effects on latera..."
...In the present study, the clay bed was prepared similar to the procedure adopted by Narasimha Rao et al. (1998) and Chandrasekaran et al. (2010)....
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...2D) and the corresponding load was taken as allowable lateral-load capacity of the pile (Narasimha Rao et al. 1998; Chandrasekaran et al. 2010)....
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...(1998) and Chandrasekaran et al. (2010). First, the model aluminium piles placed in the centre of the test tank using templates and then uniformly mixed clay was placed and hand packed in the test tank in layers of 50 mm thickness....
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...The lateral load was applied till the lateral deflection reaches 20% of pile diameter (0.2D) and the corresponding load was taken as allowable lateral-load capacity of the pile (Narasimha Rao et al. 1998; Chandrasekaran et al. 2010)....
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TL;DR: In this article, a detailed literature review on soil-structure interaction analysis of laterally loaded piles is presented, which is highly essential for predicting a more accurate structural behavior so as to improve the safety of structures under extreme loading conditions.
Abstract: Soil–structure interaction plays an important role in the behavior of structure under static or dynamic loading. It influences the behavior of soil, as well as the response of pile under loading. The analysis is highly essential for predicting a more accurate structural behavior so as to improve the safety of structures under extreme loading conditions. The soil–pile system behavior is predominantly nonlinear and this makes the problem complicated. In a laterally loaded pile the load is resisted by the soil–pile interaction effect, which in turn depends on soil properties, pile material, pile diameter, loading type and bed slope of ground. The difficulty in the accountability of the influencing factors necessitates a careful study on soil–structure interaction problem. The analysis became easier with the debut of powerful computers and simulation tools such as finite element analysis software. A detailed literature review on soil–structure interaction analysis of laterally loaded piles is presented in this paper.
37 citations
References
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Book•
01 May 1990
TL;DR: In this paper, the authors present a consistent theoretical approach to the prediction of pile deformation and load capacity, and present parametric solutions for a wide range of cases, demonstrating how such solutions can be used for design purposes, and review the applicability of these approaches to practical problems.
Abstract: This book deals with methods of analysis that may be useful in design of pile foundations. The aims are to: 1) present a consistent theoretical approach to the prediction of pile deformation and load capacity, 2) present parametric solutions for a wide range of cases, 3) demonstrate how such solutions can be used for design purposes, and 4) review the applicability of these approaches to practical problems. (TRRL)
1,415 citations
01 Jan 1970
1,104 citations
TL;DR: In this article, a large-scale group of steel pipe piles and an isolated single pile were subjected to two-way cyclic lateral loading in a submerged firm to dense sand that was placed and compacted around the piles.
Abstract: A large‐scale group of steel pipe piles and an isolated single pile were subjected to two‐way cyclic lateral loading. The tests were conducted in a submerged firm to dense sand that was placed and compacted around the piles. All of the piles were extensively instrumented so that the variation in soil resistance within the group could be determined. The response of the piles in the group was also compared with the response of the isolated single pile. The loss of efficiency of the piles in the group was related principally to “shadowing” (i.e., the loss of soil resistance of piles in the trailing rows). Piles in the leading row supported a large proportion of the group load and behaved similarly to the isolated single pile. Two‐way cyclic loading had little effect on the distribution of load to the piles in the group, but tended to densify the sand around both the single pile and the group piles.
355 citations
TL;DR: In this article, a static lateral load test was performed on a full-scale pile group to determine the resulting pile-soil-pile interaction effects, and good agreement between the measured and computed pile group responses was obtained using the p-multiplier approach.
Abstract: A static lateral load test was performed on a full-scale pile group to determine the resulting pile-soil-pile interaction effects. The 3 × 3 pile group at three-diameter spacing was driven into a profile consisting of soft to medium-stiff clays and silts underlain by sand. The piles were instrumented with inclinometers and strain gages. The load carried by each pile was measured. A single pile test was conducted for comparison. The pile group deflected over two times more than the single pile under the same average load. Group effects significantly reduced load capacity for all rows relative to single pile behavior. Trailing rows carried less than the leading row, and middle row piles carried the lowest loads. Maximum moments in the group piles were 50–100% higher than in the single pile. P-multipliers were 0.6, 0.38, and 0.43 for the front, middle, and back row piles, respectively. Good agreement between the measured and computed pile group responses was obtained using the p-multiplier approach. Design c...
246 citations