Analysis of floating and end-bearing pile foundations affected by deep-excavations

TY - JOUR

T1 - Analysis of floating and end-bearing pile foundations affected by deep-excavations

AU - Zheng, Chen

AU - Franza, Andrea

AU - Jimenez, Rafael

PY - 2023/1

Y1 - 2023/1

N2 - This paper investigates the response of pile foundations to deep-excavations. An elastoplastic two-stage model is used to study the response of pile groups (with free- or rigidly capped-heads) and of piled structures (grade beams or bearing walls), considering piles embedded in either uniform or layered ground. The model is validated using results of analytical solutions, as well as data from centrifuge tests and from real case histories. Then, a parametric study investigates excavation-induced displacements and internal forces of piles, and deformations of the superstructure. Soil–pile transfer mechanisms and pile–superstructure interactions are analysed for various foundations and ground conditions, with results showing that settlements and slopes between piles are larger for floating piles than for end-bearing piles. Results show that rigidly capped piles and semi-flexible piled structures cause bending moments at the foundation heads that increase with the excavation-induced slope between piles, whereas the risk for tensile failure of piles is low. Also, results indicate that the superstructure stiffness is more relevant to decrease the slope and deflection ratio of foundations when composed of floating piles, compared to end-bearing piles. Finally, modelling end-bearing piles embedded in a stiff base using hinged connections to such stiff base may not be appropriate.

AB - This paper investigates the response of pile foundations to deep-excavations. An elastoplastic two-stage model is used to study the response of pile groups (with free- or rigidly capped-heads) and of piled structures (grade beams or bearing walls), considering piles embedded in either uniform or layered ground. The model is validated using results of analytical solutions, as well as data from centrifuge tests and from real case histories. Then, a parametric study investigates excavation-induced displacements and internal forces of piles, and deformations of the superstructure. Soil–pile transfer mechanisms and pile–superstructure interactions are analysed for various foundations and ground conditions, with results showing that settlements and slopes between piles are larger for floating piles than for end-bearing piles. Results show that rigidly capped piles and semi-flexible piled structures cause bending moments at the foundation heads that increase with the excavation-induced slope between piles, whereas the risk for tensile failure of piles is low. Also, results indicate that the superstructure stiffness is more relevant to decrease the slope and deflection ratio of foundations when composed of floating piles, compared to end-bearing piles. Finally, modelling end-bearing piles embedded in a stiff base using hinged connections to such stiff base may not be appropriate.

KW - Building deformations

KW - Deep-excavations

KW - Layered soil

KW - Piles

KW - Soil movements

KW - Soil–structure interaction

UR - https://www.scopus.com/pages/publications/85143504470

U2 - 10.1016/j.compgeo.2022.105075

DO - 10.1016/j.compgeo.2022.105075

M3 - Journal article

SN - 0266-352X

VL - 153

JO - Computers and Geotechnics

JF - Computers and Geotechnics

M1 - 105075

ER -