scholarly journals CUMULATIVE DAMAGE EVALUATION FOR COLLAPSE OF STEEL PILE IN LIQUEFIED SOIL SUBJECTED TO MULTIPLE EARTHQUAKES BASED ON CENTRIFUGAL TESTS OF SUPERSTRUCTURE-PILE FOUNDATION AND LIQUEFIED SOIL SYSTEM

2021 ◽  
Vol 86 (783) ◽  
pp. 749-760
Author(s):  
Moeko MATOBA ◽  
Yoshihiro KIMURA ◽  
Shuji TAMURA
Keyword(s):  
Pile Foundation ◽  
Cumulative Damage ◽  
Damage Evaluation ◽  
Soil System ◽  
Multiple Earthquakes

Model for Machine-Pile Foundation-Soil System

1971 ◽  
Vol 97 (1) ◽  
pp. 295-299
Author(s):  
M. R. Madhav ◽  
N.S.V. Kameswara Rao
Keyword(s):  
Pile Foundation ◽  
Foundation Soil ◽  
Soil System

scholarly journals Cumulative Damage Evaluation under Fatigue Loading

2008 ◽  
Vol 13-14 ◽  
pp. 141-150 ◽  
Author(s):  
L.E. Granda Marroquín ◽  
Luis Héctor Hernández-Gómez ◽  
G. Urriolagoitia-Calderón ◽  
G. Urriolagoitia-Sosa ◽  
E.A. Merchán-Cruz
Keyword(s):  
Damage Model ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Cumulative Damage ◽  
Damage Evaluation ◽  
Strain Gages ◽  
Damage Rate ◽  
Heat Treated ◽  
History Of ◽  
Nonlinear Damage Model

The goal of this paper is to present the results obtained from damage evaluation in automotive axles, which are under torsion fatigue. For this purpose, a Nonlinear Damage Model is used. The mentioned shafts have to satisfy geometry requirements and their material has to be heat treated in order to improve their performance. One has to keep in mind that fatigue strength depends on material properties and geometry. In order to make a precise evaluation of the accumulated damage, the manufactured shafts were tested. In the first instance, the mechanical properties of the material were evaluated with static torsion tests. In the next step, the S-N curves were obtained with torsion fatigue tests. In all these cases, temperature was controlled. Experimental data at different load levels was gathered with strain gages in conjunction with a data acquisition system. The life cycle history of each tested shaft was stored and with this experimental evidence, damage curves were obtained and the cumulative damage of the axle was established. With these damage curves, it is possible to define the relation between damage rate and life for different stress levels.

scholarly journals Experimental Study on Whole Wind Power Structure with Innovative Open-Ended Pile Foundation under Long-Term Horizontal Loading

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5348
Author(s):  
Junwei Liu ◽  
Zhipeng Wan ◽  
Xingke Dai ◽  
Dongsheng Jeng ◽  
Yanping Zhao
Keyword(s):  
Wind Power ◽  
Dynamic Characteristics ◽  
Pile Foundation ◽  
Large Diameter ◽  
Offshore Wind ◽  
Cyclic Loads ◽  
Loading Frequency ◽  
Soil System ◽  
Comparison Results

The offshore wind energy (OWE) pile foundation is mainly a large diameter open-ended single pile in shallow water, which has to bear long-term horizontal cyclic loads such as wind and waves during OWE project lifetime. Under the complex cyclic loads, the stress and displacement fields of the pile-soil system change continuously, which affects the dynamic characteristics of the pile foundation. Within the service life of the pile foundation, the pile-soil system has irreversible cumulative deformation, which further causes damage to the whole structure. Therefore, it is important to examine the overall dynamic characteristics of wind power foundation under high cycle. In this paper, in the dry sand foundation, taking the Burbo Bank 3.6 MW offshore turbine-foundation structure as the prototype, the horizontal cyclic loading model tests of the wind power pile foundation with the scale of 1:50 were carried out. Considering the factors such as loading frequency and cyclic load ratio, the horizontal dynamic characteristics of the whole OWE pile foundation are studied. The comparison results between the maximum bending moment of pile and the fitting formula are discussed. In conclusion, moment of OWE pile shaft is corresponding to the loading frequency (f = 9 HZ) and loading cycles by fitting formulas. The fatigue damage of the OWE pile does not occurs with low frequencies in high cycles.

scholarly journals Numerical analysis of the forming process of the bearing capacity of the auxiliary pile foundation in Permafrost area

2020 ◽  
Vol 198 ◽  
pp. 02002
Author(s):  
Sun Jianzhong ◽  
Guo Chunxiang ◽  
Wang Xu ◽  
Zhang Weijia
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Initial Conditions ◽  
Interface Temperature ◽  
Engineering Practice ◽  
Confined Water ◽  
Foundation Soil ◽  
Soil System ◽  
Heat Transfer Theory ◽  
Bridge Pile Foundation

Bore Cast-in-place Piles broke the original water and heat balance state of the stratum in the bridge construction of Qinghai Tibet railway. The settlement of a bridge pile foundation was relatively large after more than ten years of operation. It was found that there is confined water in the foundation soil after investigation. Engineers planned to add auxiliary piles at the original pile side to reduce the settlement of the pile foundation.This paper studied the temperature change, bearing capacity formation rule and long-term bearing capacity change trend of the new pile-soil system after adding auxiliary piles on the original foundation, which provides certain theoretical basis and reference basis for engineering practice. A three-dimensional model of a bridge pile foundation was established by numerical method. Considering the influence of atmospheric temperature, hydrogeological conditions, concrete temperature into the mold, and the temperature of underground confined water, based on the heat transfer theory, the boundary conditions and initial conditions are given. The influence of the change of ground temperature field and the change of pile-soil interface temperature on the bearing capacity of the foundation was studied after the auxiliary pile was poured. The analysis shows that the measure to increase the bearing capacity by adding auxiliary piles is a double-edged sword. On the one hand, the auxiliary piles themselves constitute the bearing capacity together with the original pile foundation after thawing, on the other hand, the auxiliary piles are constructed by the method of pouring concrete in the field. The hydration heat of concrete makes the temperature of the original foundation soil rise, and reduces its bearing capacity. The whole bearing capacity will not be increased at the initial stage, but also will be temporarily reduced, and the whole bearing capacity will be formed after the frozen soil is frozen back in the later stage.

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