Longitudinal-vibration analysis method of pile foundation in radial-heterogeneity and longitudinal-stratification soil body

Abstract

The invention discloses a longitudinal-vibration analysis method of a pile foundation in a radial-heterogeneity and longitudinal-stratification soil body. For the soil body around a pile, a three-dimensional axisymmetric model is adopted, vertical wave effect is considered, and the soil body around the pile is divided into any number of layer sections along a longitudinal direction; each layer section of the soil body around the pile is divided into an internal disturbance zone and an external zone along a radial direction; the internal disturbance zone is divided into any number of circle layers along the radial direction, and each circle layer of the soil body is respectively a homogeneous, isotropic, linear and viscoelastic body; a soil body in the external zone infinitely extends alongthe radial direction; for soil body material damping, viscous damping is adopted to establish a longitudinal-vibration equation of the soil body around the pile and a pile body under a three-dimensional axisymmetric condition according to basic theory of elastic dynamics; and Laplace transform and a method of separation of variables are used to solve the vibration equation to obtain a time-domainvelocity response function of any excitation force acting on a pile top.

Description

technical field [0001] The invention relates to the field of civil engineering, in particular to a method for analyzing the longitudinal vibration of pile foundations in radially heterogeneous and longitudinally layered soil bodies. Background technique [0002] The research on the coupled vibration characteristics of the pile-foundation interaction system in the longitudinally layered soil is the theoretical basis of engineering technology fields such as pile foundation anti-seismic design and pile foundation dynamic testing. Cross-cutting hot issues in the field of interaction. [0003] The study of pile-soil coupled vibration characteristics is the theoretical basis of engineering technology fields such as seismic design of pile foundations and dynamic testing of pile foundations, and has always been a hot issue in geotechnical engineering and solid mechanics. [0004] As we all know, in the process of pile foundation construction, due to the influence of soil compaction...

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Problems solved by technology

However, for the problem of anharmonic vibration (transient vibration or random vibration), the hysteretic damping model is not suitable, especially when studying the time domain response of piles under transient excitation conditions, the soil damping force is also related to the amplitude Related to the strain rate, the use of the hysteretic damping model will cause contradictions in the concept, resulting in the so-called "non-causality of dynamic response", while the viscous damping model is more suitable and more reasonable in physics

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