Laterally loaded piles in permafrost

1984 ◽  
Vol 21 (3) ◽  
pp. 431-438 ◽  
Author(s):  
J. F. (Derick) Nixon
Keyword(s):  
Numerical Procedure ◽  
Ground Surface ◽  
Surface Displacement ◽  
Field Tests ◽  
Creep Model ◽  
Sustained Load ◽  
Laboratory Model ◽  
Secondary Creep ◽  
Laterally Loaded Piles ◽  
Laterally Loaded

A theory for the design of laterally loaded piles in permafrost is presented. The approach is valid for icy soils or ice, where secondary creep displacements will be responsible for the majority of the soil strain under sustained load. Initially, the paper studies in some detail the response of a short, rigid pile embedded in a nonlinear viscous medium. The concept of a flexible elastic pile in a viscous continuum is then introduced, and a relatively straightforward numerical procedure must be introduced to obtain a solution. Once the limiting or design ground surface displacement rate is established by the designer, the paper shows how a typical chart relating lateral pile load to average ground temperature can be prepared.The available (but limited) data base is reviewed for field pile load tests carried out in the early 1970's in Inuvik, N.W.T. and some laboratory model pile tests carried out in connection with this study. Using available long-term secondary creep data for ice and icy silts, predictions for the lateral creep response of piles can be carried out. Agreement between prediction and observation is certainly encouraging and points the way to further research and field testing in this area. Finally, the paper briefly discusses the resistance of rigid fixed-headed piles to lateral loads, and the resistance of a pile in permafrost to the application of a pure moment. Key words: lateral piles, permafrost, creep, model, field tests.

scholarly journals A Simplified Calculation Method for the Near-Slope Laterally Loaded Pile Based on a Passive Wedge Model

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Minghui Yang ◽  
Bo Deng ◽  
Yuhui Wang
Keyword(s):  
Slope Angle ◽  
Field Tests ◽  
Internal Force ◽  
Laboratory Model ◽  
Loading Capacity ◽  
Soil Resistance ◽  
Laterally Loaded Piles ◽  
Solution Methods ◽  
Simplified Calculation ◽  
Laterally Loaded

When a pile is placed near the slope, the lateral loading capacity of the pile decreases significantly due to the weakening effect of soil resistance near the slope. As such, a modified soil passive wedge model for near-slope laterally loaded piles is presented to consider the weakening effect in this paper. According to development depth of different wedges, the shapes of soil passive wedge can be classified into three sorts, so as to fully analyze the influence of the slope shape and the distance from the pile center to the slope crest. On this basis, a concept of equivalent depth is proposed considering the differences of laterally loaded piles near the slope and in the horizontal ground. Besides, the unit ultimate soil resistance, which can be obtained along the different depths of pile, is introduced into the p-y curve of the soil, for achieving solution methods of internal force and displacement of laterally loaded piles under the slope weakening effect. The results of laboratory model and field tests on laterally loaded piles are compared with the proposed method, demonstrating its validity and accuracy. Furthermore, the influence of the near-slope distance on the loading capacity of the pile is fully analyzed in detail, indicating the critical near-slope distance is increasing with the increase of the undrained strength, while independent of the slope angle.

scholarly journals Experimental observation on laterally loaded pile in unsaturated silty soil

2019 ◽  
Vol 56 (11) ◽  
pp. 1545-1556 ◽  
Author(s):  
L.M. Lalicata ◽  
A. Desideri ◽  
F. Casini ◽  
L. Thorel
Keyword(s):  
Water Table ◽  
Ground Surface ◽  
Bending Moment ◽  
Data Interpretation ◽  
Partial Saturation ◽  
Laterally Loaded Piles ◽  
Silty Soil ◽  
Centrifuge Tests ◽  
Surface Data ◽  
Laterally Loaded

An experimental study was carried out to investigate the effects of soil partial saturation on the behaviour of laterally loaded piles. The proposed study was conducted by means of centrifuge tests at 100g, where a single vertical pile was subjected to a combination of static horizontal load and bending moment. The study was conducted on a silty soil characterized with laboratory testing under saturated and unsaturated conditions. During flight, two different positions of water table were explored. The influence of density was investigated by compacting the sample with two different void ratios. Finally, the effects of a variation of saturation degree on the pile response under loading were studied by raising the water table to the ground surface. Data interpretation allows drawing different considerations on the effects of partial saturation on the behaviour of laterally loaded piles. As expected, compared to saturated soils, partial saturation always leads to a stiffer and resistant response of the system. However, the depth of the maximum bending moment is related to the position of the water table and the bounding effects induced by partial saturation appear to be more important for loose soils.

Laterally Loaded Piles With Bulge

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Jan Dührkop ◽  
Jürgen Grabe
Keyword(s):  
Bearing Capacity ◽  
Ground Surface ◽  
Steel Plates ◽  
Small Scale ◽  
Calculation Methods ◽  
Laterally Loaded Piles ◽  
Standard Methods ◽  
Theoretical Investigations ◽  
Innovative System ◽  
Laterally Loaded

This paper contains several investigations on the behavior of bulged piles. Bulge means the application of vertical steel plates somewhere near the ground surface to improve the lateral bearing capacity. The results of small scale tests in sand are illustrated, which demonstrate the effectiveness of such bulge. Some theoretical investigations are presented trying to apply standard methods like the p‐y-curve procedure to the design of bulged piles. An outline of possible calculation methods is given. Investigations on two different exemplary pile systems demonstrate the behavior of the bulged structure and give an idea of the advantages of this innovative system.

Laterally Loaded Piles With Bulge

2007 ◽  
Author(s):  
Ju¨rgen Grabe ◽  
Jan Du¨hrkop
Keyword(s):  
Bearing Capacity ◽  
Ground Surface ◽  
Steel Plates ◽  
Small Scale ◽  
Calculation Methods ◽  
Laterally Loaded Piles ◽  
Standard Methods ◽  
Theoretical Investigations ◽  
Innovative System ◽  
Laterally Loaded

This paper contains several investigations on the behaviour of bulged piles. Bulge means the application of vertical steel plates somewhere near ground surface to improve the lateral bearing capacity. The results of small scale tests in sand are illustrated, which demonstrate the effectiveness of such bulge. Some theoretical investigations are presented trying to apply standard methods like the p-y-curve procedure to the design of bulged piles. An outline of possible calculation methods is given. Investigations on two different exemplary pile systems demonstrate the behaviour of the bulged structure and give an idea of the advantages of this innovative system.

Design of Laterally Loaded Piles With Bulge

2009 ◽  
Author(s):  
Jan Du¨hrkop ◽  
Ju¨rgen Grabe
Keyword(s):  
Power Plants ◽  
Ground Surface ◽  
Steel Plates ◽  
Offshore Wind ◽  
Laterally Loaded Piles ◽  
Offshore Wind Power ◽  
Wind Power Plants ◽  
Design Charts ◽  
Curve Method ◽  
Laterally Loaded

Several investigations on the behaviour of bulged piles have shown the benefit of this construction. Bulge means the application of vertical steel plates somewhere near ground surface to improve the lateral bearing capacity. This paper contains the description of a modified P-y curve method which is capable of calculating piles with bulge. Based on this procedure hundreds of different monopile foundations for offshore wind power plants are analysed and results are used to create design charts. Therefore the Characteristic Load Method (CLM) is expanded to considere the effect of a bulge.

Laboratory model tests on laterally loaded piles in plastic clay

2013 ◽  
Vol 7 (3) ◽  
pp. 241-250 ◽  
Author(s):  
Y E-A Mohamedzein ◽  
F A E Nour Eldaim ◽  
A B Abdelwahab
Keyword(s):  
Model Tests ◽  
Laboratory Model ◽  
Laterally Loaded Piles ◽  
Plastic Clay ◽  
Laterally Loaded

A streamline solution for rigid laterally loaded piles in permafrost

1989 ◽  
Vol 26 (4) ◽  
pp. 568-574 ◽  
Author(s):  
A. Foriero ◽  
B. Ladanyi
Keyword(s):  
Velocity Field ◽  
Creep Rate ◽  
Secondary Creep ◽  
Laterally Loaded Piles ◽  
Creep Response ◽  
Soil Movement ◽  
State Of Stress ◽  
Bound Theorem ◽  
Laterally Loaded ◽  
Secondary Creep Rate

A streamline solution for the design of laterally loaded rigid piles in permafrost is presented. The proposed method relies on a power law to describe the rate dependence of permafrost creep response. It describes the soil movement with a kinematically admissible velocity field and estimates the overall reaction at a given pile section with the bound theorem for a creeping material. The approach is valid only for a secondary creep rate and a stationary state of stress. Key words: pile, lateral load, velocity field, secondary creep rate.

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