Boundary Effects of Pile Cap on the Integrity Testing of Group Piles

Study on Group Piles Effects of Offshore Engineering under Lateral Load

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.919-921.824 ◽

2014 ◽

Vol 919-921 ◽

pp. 824-827

Author(s):

Sheng Jie Di ◽

Ming Yuan Wang ◽

Wen Bo Du

Keyword(s):

Lateral Load ◽

Soil Reaction ◽

Single Pile ◽

Soil Pressure ◽

Lateral Capacity ◽

Offshore Engineering ◽

Complex Process ◽

Pile Cap ◽

Practical Engineering ◽

Group Piles

The mechanical behavior of group piles under lateral load is a very complex process of pile-soil interaction. Due to the group effect, the lateral capacity of individual piles can not be fully developed. Deduction factors are applied to the lateral soil reaction, and then lateral analysis is performed for individual piles. After p-y curve for each pile is constructed, the soil pressure of group piles is the sum of soil pressure of single pile at the same deflection under one pile cap. The mechanical different behaviors of the front piles and the back piles are analyzed and compared based on a practical engineering.

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Integrity Testing of Three Model Piles with a Pile Cap

Journal of Testing and Evaluation ◽

10.1520/jte20170770 ◽

2018 ◽

Vol 47 (3) ◽

pp. 20170770

Author(s):

Jiunnren Lai ◽

Pei-Cheng Yang ◽

Bo-Huan Yang

Keyword(s):

Integrity Testing ◽

Pile Cap

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Study on Bearing Capacity of Prestressed Pipe Pile Foundation Under Horizontal Load

The Open Construction and Building Technology Journal ◽

10.2174/1874836801711010301 ◽

2017 ◽

Vol 11 (1) ◽

pp. 301-312 ◽

Cited By ~ 2

Author(s):

Jin Xu ◽

Lin Ma

Keyword(s):

Bearing Capacity ◽

Bending Moment ◽

High Strength ◽

Horizontal Load ◽

Horizontal Force ◽

Pipe Pile ◽

Steel Bar ◽

Steel Bars ◽

Pile Cap ◽

Group Piles

Background and Objective: Prestressed high strength concrete pipe pile (PHC) shows brittle fracture when subjected to more than its own bearing capacity. Therefore, the non-prestressed steel bar is added to the PHC pipe pile, that is, the mixed reinforced pipe pile (PRC). The mechanical behavior of PRC group piles and PHC group piles under horizontal force is studied, and the bending moment diagram and displacement diagram of the pile body are compared so as to find the weak parts. Material and Method: In this paper, Φ600 pipe piles are chosen, and the PRC pipe piles are made of non prestressed steel bars of the same number as the prestressing steel bars, and the two steel bars are spaced apart. Referring to a specific project of Binhai New Area, the geological parameters are used, and the force analysis of group piles under horizontal force is carried out by using the ANSYS software. Results: ANSYS simulation results show that, under the horizontal loading, when the number of piles in group piles is different, the locations of maximum bending moments are different. Increasing the number of the PRC pipe pile with non prestressed reinforcement can effectively reduce the maximum bending moment of the pile body. Conclusion: Under horizontal load, with the increase of pile number and the pile cap aggrandizement, the position of maximum moment of pile body is shifted from 5-8 times diameter of pile to the top of pile. When the pile number reaches a certain amount, the maximum bending moment will appear at the joint between the pile cap and the pile body. At the same time, increasing the non prestressed steel bar does not influence the bending moment, and the reinforcement of the pile cap and the pile top should be strengthened.

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Theoretical solutions of laterally loaded fixed-head piles in elastoplastic soil considering pile-head flexural yielding

Canadian Geotechnical Journal ◽

10.1139/cgj-2018-0593 ◽

2020 ◽

Vol 57 (5) ◽

pp. 650-660

Author(s):

Jiunn-Shyang Chiou ◽

Jia-Qi You

Keyword(s):

Analytical Solutions ◽

Flexural Behavior ◽

Pile Head ◽

Capacity Curves ◽

Beam Elements ◽

Nonlinear Responses ◽

Pile Cap ◽

Yield Displacement ◽

Group Piles ◽

Laterally Loaded

Group piles with a cap under lateral loading behave like fixed-head piles because of the rotational restraint of the pile cap. They are susceptible to flexural yielding at the pile head due to high bending strains. In addition to soil nonlinearity, the pile-head flexural nonlinearity also significantly contributes to nonlinear responses of the piles, which is not covered in most existing analytical solutions. For a fixed-head pile buried in uniform elastoplastic soils, this study derives analytical solutions for the lateral responses to account for soil yielding, and flexural yielding and failure of the pile section at the pile head. The model assumes elastoplastic Winkler-type soil with constant subgrade stiffness and yield strength and a nonlinear moment–curvature curve for the pile section. Examples are provided to apply the solutions to determine the complete capacity curves (moment and horizontal load) of a fixed-head pile and the derived analytical capacity curves are in good agreement with those from numerical analyses that use nonlinear beam elements to reflect the nonlinear flexural behavior of the pile section. The solutions are also applied to evaluate the influences of the yield displacement of the soil and different forms of simplified nonlinear moment–curvature curves of the pile section on the lateral load–displacement curves.

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