Simplified analytical solution for stress concentration ratio of piled embankments incorporating pile–soil interaction

Abstract

Piled embankments have been extensively used for high-speed rail over soft soils because of their effectiveness in minimizing differential settlement and shortening the construction period. Stress concentration ratio, defined as the ratio of vertical stress carried by pile heads (or pile caps if applicable) to that by adjacent soils, is a fundamental parameter in the design of piled embankments. In view of the complicated load transfer mechanism in the framework of embankment system, this paper presents a simplified analytical solution for the stress concentration ratio of rigid pile-supported embankments. In the derivation, the effects of cushion stiffness, pile–soil interaction, and pile penetration behavior are considered and examined. A modified linearly elastic-perfectly plastic model was used to analyze the mechanical response of a rigid pile–soil system. The analytical model was verified against field data and the results of numerical simulations from the literature. According to the proposed method, the skin friction distribution, pile–soil relative displacement, location of neural point, and differential settlement between the pile head (or cap) and adjacent soils can be determined. This work serves as a fast algorithm for initial and reasonable approximation of stress concentration ratio on the design aspects of piled embankments.

Ground vibration induced by high speed trains on an embankment with pile-board foundation: Modelling and validation with in situ tests

“…Thus, at the interfaces, static friction is considered instead of kinetic friction. More complex pile-soil interaction will be explored in the future [39].…”

Theoretical method for additional horizontal stress of isolation piles due to adjacent loading

“…[23][24][25][26] Considering complex conditions in the interaction between pile and soil, other calculation models for calculating the ultimate soil pressure on pile were proposed. [27][28][29][30][31] Based on the calculated horizontal soil pressure, the horizontal deformation of the pile foundation was then studied. Existing studies showed that the displacement of high-speed railway pile was mainly lateral displacement, 32 which was closely related to the loading conditions.…”

“…Accounting for interaction between pile and soil, p‐y method was used to obtain the stress characteristics 23–26 . Considering complex conditions in the interaction between pile and soil, other calculation models for calculating the ultimate soil pressure on pile were proposed 27–31 …”

Stress distribution in roadbeds of slab tracks with longitudinal discontinuities

“…For CRTS (China Railway Track System) I and CRTS III prefabricated slab tracks [2], the expansion joints of track slabs and concrete bases would reduce the stiffness of track structures, thus affecting the dynamic performance of inhomogeneous, layered foundations through local stress and stress concentration due to irregularities in structural geometry [6,7]. As a result of the geometry of concrete bases in ballastless slab tracks, the vibration intensities of the slabs at both ends were substantially stronger than those in the middle.…”

“…Fig 6. Variation of numerical longitudinal influencing length of stress on roadbed with coefficient of friction, compared against the theoretical and field data[17] …”